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LIST OF TECO COMMANDS, TECO VERSION 839
Last updated 12 November 1979. Z=215667
(Note that an uparrow followed immediately by another character
signifies a control character, except inside FS flag names, where
that is not necessary because control characters are not allowed.)
^@:
<n>^@ for nonnegative <n>, is the same as ".,.+<n>".
For negative <n>, is the same as ".+<n>,.".
"10^@XA" puts the 10 characters after the pointer
in a string in qreg A.
<n>,0^@ returns -<n>; this is often useful.
<m>,<n>*0^@ returns -<m>; it undoes the ",<n>".
In other words, it extracts the first of two args.
If you want <m> instead of -<m>, use another ,0^@.
<m>,<n>^@
returns the value <n>-<m>.
<m>,<n>:^@
returns <n>,<m>.
^A inclusive-or (an arithmetic operator).
^A may be used in a file specification as the first or
the second filename to stand for the default first name.
^B is a command for cleaning up after failing searches.
If the last search was successful, ^B does nothing.
If the last search failed, ^B moves to the end of the
range searched if it was a forward search; to the beginning,
if it was a backward search. :^B does the same thing for
failing searches but does FKC after successful ones.
Note: ^B inside search string is a
special char which is matched by any
delimiter character. The set of delimiter chars is
specified by the contents of q-reg ..D; initially, the
delimiter characters are precisely the non-squoze
characters (that is, all except letters, digits, ".",
"%" and "$").
^B may be used in a file specification as the first
or second file name to stand for the default second name.
^C when typed in from console, terminates the
command string, and starts execution. If
the command executes without error, TECO
returns to its superior without flushing the type-in
buffer. When proceded, it will automatically
redisplay the buffer on display consoles.
When TECO returns, AC 2 will contain
the address of the 7-word "buffer block" describing the current
buffer - see the section "buffer block" at the end.
To type in a ^C in a TECO command string, use ^]^Q^C,
which is specially arranged to inhibit the normal
action of ^C at command string read-in time.
A ^C encountered as a command is an error.
^F inserts its string argument, after deleting the last
thing found with an S search or inserted with I or \
(won't work if pointer has moved since the S, I or \
was done). Precisely, ^F is the same as FKDI.
^G causes a "quit" by setting FS QUIT to nonzero.
The consequences of that depend on the value
FS NOQUIT. Normally, FS NOQUIT is 0; ^G will then
stop whatever TECO is doing and return to its top-level
loop, or to the innermost ^R invocation if any, to
read more commands (but first TECO will
redisplay the buffer). In particular, it will cancel a
partially typed-in command string.
All unread input except the ^G itself is flushed.
On printing terminals, output is also discarded.
(If FS NOQUIT is -2 or less, this is inhibited).
If FS NOQUIT is positive,
^G still sets FS QUIT but that has no effect. Thus,
a program can inhibit quitting temporarily, or quit
in its own manner by testing FS QUIT itself.
If FS NOQUIT is negative, setting FS QUIT nonzero
causes an ordinary error (whose error code is "QIT"),
which may be caught by an errset (:< - >). If FS NOQUIT
is less than -1, then in addition the input and output
on the terminal are not discarded.
^H backspace; it is illegal as a command.
^I tab; in bare TECO, it is a self-inserting character.
In EMACS, or whenever FS ^I DISABLE is appropriately set,
it is equivalent to a space. In bare TECO, it inserts itself
as well as the following string argument, so that Tab is
equivalent to I Tab. This was intended to be typed by the
user himself; using it in a macro is foolish.
^J line feed; flushes current value.
^K valrets a string argument to DDT with
dollar signs replaced by altmodes.
(To cause a dollar sign to be valretted, use
"^]^Q$" (ctl-close ctl-Q dollar)).
If the command string contains an P
command, TECO command execution will
continue with the character after the
altmode ending the text string of the ^K.
^K causes TECO to believe that the screen has
been clobbered, so it will automatically clear the
screen and redisplay everything at the next
opportunity. To avoid this, use "@^K" (if for
example you know DDT will not type anything out,
and will P the TECO).
When TECO executes the .VALUE, AC 2 will contain
the address of the 7-word "buffer block" describing the
current buffer - see the section "buffer block" at the end.
^L form feed; clears screen on displays (when executed,
not when typed). See F+ for more details.
^M carriage return; flushes current value.
If FS STEP MACRO is a string, it is executed (if there is a
^J after the ^M, it is skipped over first). If FS STEP MACRO
is a nonzero number, ^M does these things designed to
step through the program a line at a time:
it displays the buffer unless there was typeout recently,
then reads in a character and acts according to it.
Most characters simply tell ^M to return so that more
commands will be executed. However, there are the
following special characters:
^F quit. Like ^G, but ignores the setting
of FS NOQUIT and does a real quit.
^P end stepping. Zeroes FS STEP MACRO and then
proceeds without stepping.
^R enter ^R mode. On return from ^R,
another character will be read and decoded.
^N:
<n>^N sets the FS LINES flag to <n>. Like "<n>FS LINES".
FS LINES controls the number of lines used for buffer
display and, on display terminals, for all other output.
:^N complements the FS TTMODE flag (initially 0).
TECO normally displays the buffer on printing terminals
only if this flag is set. User buffer display macros
should exhibit similar behavior.
:<n>^N like "<n>^N :^N"
Note: ^N in a search string is a special char which is
matched by any char other than the char after
the ^N in the search string.
^O<filename>
bigprints <filename> on the device open for output.
Note: ^O in a search string is a special character
signifying "OR" i.e., it divides the search string into
two strings either of which will satisfy the search.
Thus, SFOO^OBAR will find either FOO or BAR, whichever is
encountered first.
^P alphabetic (ASCII) or numeric sort command.
The entire buffer, or the part within the virtual boundaries,
is sorted, after being divided into sort records
(i.e., things to be sorted) on the basis of the arguments
given to the command in the form of
three TECO command strings following
the ^P, separated by altmodes
(Notes: (1) two successive null args
will result in a premature end of
command input, so use spaces where
needed; (2) a dollar sign in any
arg will be replaced by an altmode;
(3) the three args will be left in q-regs ..0, ..1, ..2).
The three expressions are used to divide the buffer into sort
records, each of which has a sort key.
A sort key may be any substring of the record, or it may
be a number. The records and keys are found as follows:
1. The pointer is moved to the
beginning of the buffer, which is the
beginning of the first sort record.
2. The first command string is executed.
If the key is to be a substring of the record,
this command string should leave point at the
beginning of the key. If the key is to be a number,
it does not matter what this command string does.
3. The second command string is executed.
If this command string returns a value, that value is the key.
Otherwise, this command string should leave point at the end
of the key.
4. The last command string is executed.
This should move the pointer to the end of the sort record,
which is also the beginning of the next record.
5. If step 3 or 4 leaves the pointer
at the end of the buffer, or
executes a search which fails (this
will not cause an error; those
steps are done as if inside an
iteration), the creation of sort
records is complete, and the sort
takes place. Otherwise, go back
to step 2.
Sort records and keys may be variable length.
No character (i.e., a shorter key) sorts before ^@,
and keys are considered left-justified for the comparison.
Numeric keys are always "less" than any string keys.
There is nothing to prevent overlapping records
from being specified; the sort will copy each record
so the overlap region will be duplicated.
Insertion and deletion are allowed but know that
TECO remembers the boundaries of records and keys as character
numbers, so deleting chars from a record already delimited
will shift chars from the next record into it, etc.
The sort is stable. :^P sorts in reverse order.
If FS ^P CASE is nonzero, ^P ignores case; that is,
it sorts lowercase letters as if they were the
corresponding uppercase letters.
^Q ^Q in a search string causes
the next char to be quoted, i.e.,
it is treated as an ordinary char
even if it normally has a special
meaning ("^Q^Q" is a normal ^Q;
^Q works only at execution time, not at command string
read-in time, so rubout cannot be ^Q'd).
This also works inside file name specifications.
^R MODE
^R real time edit feature, intended mainly for display terminals.
The position of the pointer is represented by the terminal's
hardware cursor, rather than by any printed characters (^R
ignores the contents of ..A, except on printing terminals).
All non-control-non-rubout characters
are normally self inserting; the others are normally
editing commands. The user may redefine any character
by means of the FS ^RCMAC flag.
In ^R mode echoing is turned off, so typed-in characters
manifest themselves only by their effect on the displayed
buffer contents (but see FS ^R ECHO).
Any command may be given a numeric argument, which most
commands (including all characters that insert themselves)
treat as a repetition count. If no argument is specified,
1 is the default, but commands can distinguish between
an explicit 1 and a defaulted 1. The argument is computed as
follows: <arg> = <basic arg> * (4 ** <exponent-of-4>)
where <basic arg> is the explicit argument, if any, or
1 otherwise. An explicit argument is given with ^V or
by control-digits. <expt-of-4> is initially 0
and incremented by ^U. All commands except argument-setting
commands discard their arguments even if they don't use
the arguments. Three flags contain the argument data:
FS ^R ARG contains the explicit argument, if any, else 0;
FS ^R EXPT contains the exponent of 4;
FS ^R ARGP, if zero, indicates that no arg has been
specified (neither the explicit arg nor the exponent of 4);
if 1, indicates that only an exponent of 4 has been
specified, and the basic arg is still 1;
if 3, indicates that an explicit arg has been specified.
The 4 bit, if set, indicates that the argument should
be negated (Control-Minus sets this bit)
All three are zeroed after any command that doesn't identify
itself as an argument setting command by clearing FS ^R LAST.
Any character may have a
program associated with it, using the FS ^RCMACRO command.
If that is done, when that character is typed, TECO
will execute the program instead of inserting the char
or using it as a built-in command. The definition of a
character may also be treated as a q-register in the
"Q", "U", "X", "G", "[", "]", "M" and "FQ" commands;
see "Q" for directions. When the program is executed,
q-reg ..0 will contain the character being handled.
When errors take place inside ^R, or in macros called
from ^R, after printing the error message TECO returns
control to the innermost invocation of ^R (unless
FS *RSET or ..P is nonzero). The same thing happens
for quits. See ..P.
One may wish to have
a mode in which most editing commands are disabled, and
most characters that are normally editing commands are
self-inserting instead. The FS ^RSUPPRESS flag, when
nonzero, suppresses all built-in commands except rubout
and all user defined commands whose definitions do not
begin with "W" (since "W" at the beginning of a macro
is a no-op, the only reason to have one there is to
prevent suppression). When a character is suppressed
as a command, it becomes self-inserting. An additional
feature is the FS CTL MTA flag; when it is negative,
all control-meta-letters (and ctl-meta-[, ], \, ^ and _)
have their definitions suppressed; this mode is useful
when editing TECO commands.
In "replace mode", printing characters overlay a
character instead of making the line longer.
Replace mode is controlled by FS ^R REPLACE, which
see for more details. A more general facility for changing
what ALL printing characters do is FS ^R NORMAL. If this is
nonzero, it counts as the definition of all "normal"
characters. That is, the definition which all printing
characters initially have says to do whatever FS ^R NORMAL
directs, and otherwise (if it is 0) insert or replace.
You can redefine all "normal" characters whose Lisp syntax in
..D is ")" by putting a function in FS ^R PAREN. This
function will be executed IN ADDITION to the actions for
handling all "normal" characters. This is good for something
to point out the location of the matching open-parenthesis.
Normal characters which you don't redefine in one of those
ways will sometimes be subject to system echoing, when that is
implemented. This improves efficiency so it is done whenever
it is safe. Characters which have been redefined and thus
made not normal cannot be echoed by the system. If you
redefine what "normal" means by making FS ^R NORMAL nonzero,
system echoing will be turned off entirely. Sometimes Space
is redefined with a definition which never does anything but
insert a space unless the horizontal position is beyond a
certain point (at which point it will typically break the
line). Then it is desirable to enable spaces to be echoed
when the cursor has not reached that column. This can be done
by means of the FS ^R EC SD flag. Set it to the definition
which Space has in that case, and set FS ADLINE to the column
up to which it is safe to echo Space. Then, when Space
actually has that definition, the system will be told to echo
spaces but only up to that column.
By setting FS ^R INHIBIT nonzero, you inhibit display
updating. But ^R still remembers what is necessary,
and as soon as FS ^R INHIBIT is zero again the
updating will be done.
Conversely, you may wish to inhibit the feature which causes
redisplay to be suspended when input is available. Setting FS
D FORCE nonzero does this.
The ^R-mode input dispatch table is actually indexed by
9-bit TV character code. Each 9-bit code can be redefined.
The list of ^R-mode initial definitions that follows
refers to the characters obtainable on non-TV's - in other
words, the 9-bit characters which are the results of
reading in the 14-bit codes 0000 through 0177, which are
precisely the 9-bit characters which are equivalent to
some 7-bit ASCII character.
A subsystem which is not TV oriented need not worry about
the 9-bit character set; by using FI, and FS ^RCMACRO
always without the atsign modifier, it can handle ASCII
characters throughout. TECO will automatically do the
conversion to and from 9-bit characters on TV's.
For those who wish to handle the 9-bit character set,
the definitions of all 9-bit characters
are listed in the section "TECO's character sets",
along with the appropriate conversions between character
sets.
One may wish to have some operation (such as filing
the buffer away) performed every so often while in ^R
mode. See "..F" for how to do this using the
"secretary macro" feature. FS ^R DISPLAY can be set
to a macro which will be run every time ^R is about
to do nontrivial redisplay.
Although ^R mode is intended for display terminals,
the creation of large macro-systems intended for use
with ^R mode has made it necessary for ^R to work
at least marginally on printing terminals.
Since the physical cursor is not suitable, the ordinary
TECO cursor is used (whatever is in ..A). The buffer
is displayed only when the screen is "cleared", such as by
giving the built-in ^L command.
Also, unless FS ^RECHO > 0, characters actually read
by the ^R-mode command loop are typed out, although
echoing is still turned off.
This echoing can be made to happen even on displays
by making FS ^RECHO negative (this is unwise to do
if there is no echo area).
Setting FS ^R SCAN to nonzero causes ^R commands to
try to imitate printing terminal line editors by
echoing the characters that they insert/delete/move over.
In this case, FS ^R ECHO should be set to 1.
FS ^R MAX is the maximum size deletion or insertion
which ^R will try to print in the fancy way.
Note that ^R recognizes insertion, deletion, and cursor
motion from the values returned by the user's command
definitions - see the following paragraph.
Macros and ^R - reducing redisplay:
Whenever control passes from normal TECO to ^R
(that is, when a ^R is executed, when a @V is executed
within a ^R-mode macro, or when a ^R-mode macro returns),
^R must be able to update the screen according
to the changes that have been made in the buffer
since the last time ^R mode lost control. ^R can
do that in a way that makes no assumptions, but
that way is slow. If information is still available on
what areas of the buffer were changed, that info
can be passed to ^R in the form of numeric args,
and ^R will save time by assuming the info to be
correct. If the info is not correct, the screen
will not be properly updated. The options are:
no args - the usual case - means assume nothing.
One arg means that the buffer has not changed,
although the pointer may have moved. The actual
value of the arg does not matter in this case.
Two args should specify a range of the buffer
outside of which nothing was changed. ^R will
limit redisplay to that range if possible.
^R also knows what to do about macros that type text
out; if Q..H is nonzero when ^R is entered or
returned to, ^R will not do any displaying until it
has read one character (and executed it, unless it
is a space). If the selected buffer when you return to ^R is
not the same one that was selected when ^R was previously in
control, then it doesn't matter what args you give.
If you like ^R mode, try:
:I..G EL 90^S ^R :I..B Q..H"N 90^S ' ^R
The commands are:
Control-Minus
negates the argument of the next command.
Control-digits
accumulate a numeric argument for the next
command. Thus, control-5 ^N will move down
five lines.
^A go to beginning of current line (0L).
With argument, <arg>-1 L.
^B go back over previous character (R)
^C complements the state of the comment mode switch.
Types "C" for comment or "T" for text at the bottom
of the screen, to say what mode you're in.
When in comment mode, the ^N and ^P
commands begin by going to the end of the line and
if the last character is a semicolon,
deleting it and any preceding tabs.
Then, after moving to the next or previous line,
if the line has a semicolon in it the pointer
will be left after the semicolon; otherwise
the pointer will move to the end of line,
and enough tabs will be inserted to move
the pointer at least to the specified comment column,
followed by a semicolon.
Numeric argument is ignored.
^D deletes the next character after . (D)
If FS RUBCRLF is nonzero, ^D before CRLF deletes
both the CR and the LF.
^E moves to end of line (:L). With argument, <arg>:L.
^F goes forward over the next character (C)
^G flushes any numeric argument or case-shift,
unsets the mark if it had been set,
and resets the case-lock.
When ^R is actually in control (as opposed to a
macro running inside ^R), ^G's quitting action
is suppressed, and ^G acts as a command instead.
Thus, it does not flush any type-in.
^H (backspace) inserts itself.
^J (linefeed) inserts itself.
^K kills to eol (K). With arg, <arg>K.
The text deleted is put in q-reg ..K.
^L redisplays the screen (used to recover from
datapoint lossage). Chooses a new window.
A numeric argument specifies the number of lines
of buffer to display - useful on printing terminals.
On displays, if only a part of the screen is being
used at the moment, only that part is cleared.
^M inserts a carrage return-line feed.
^N goes to next line (L). With argument, <arg>L.
^O inserts a CRLF, then backs over it.
"^Ofoo" is equivalent to "foo^M" but
often requires less redisplay.
With argument, inserts <arg> CRLFs
and backs over the last.
If you want to insert several lines in the
middle of a page, try doing ^U^U^O before
and ^U^U^K afterward.
^P goes to previous line (-L). More generally, -<arg>L.
^Q inserts the folling character directly,
regardless of its meaning as a command.
If the char isn't already in the input buffer,
^Q will prompt with a "Q" at the bottom of the screen.
An argument to ^Q causes it to insert the same
character <arg> times. ^Q is not affected by
replace mode; the quoted character is always
inserted.
^R causes the column the pointer is at to become
the comment column. Argument is ignored.
^S reads a character and searches for it.
"^SA" in ^R mode is the like "SA" in TECO.
^T sets the ^R-mode mark at the current pointer
position. The mark is really the value of
FS ^RMARK and is used by the ^X and ^W commands
in ^R mode. If FS ^R MARK holds -1 there is no
mark; that is the case initially and after any
insertion, deletion or quit in ^R mode.
Attempting to use the mark when there is none
rings the bell.
^U increments the exponent-of-4 for the next command.
This usually is the same as repeating it 4 times.
Does not use any previous argument, but leaves
it around for the next command.
^V sets the basic arg for the next command.
The argument is composed of digits optionally
preceded by a minus sign, echoed at the bottom
of the screen and turned into a number in the
current radix (FS IBASE). The first non-digit
terminates the arg and is treated as a command.
^G will flush the argument.
^W kills everything between the current pointer
position and the mark, putting the deleted text
in q-reg ..K. If there is no mark, nothing is
deleted and the bell is rung.
^X sets the mark at the current pointer position,
and moves the pointer to where the mark had
been; in other words, exchanges the mark and
the pointer. Does nothing if there is no mark.
Do this several times to see both ends of the
range that a ^W command would delete.
^[ (altmode) terminates edit
^] reads a q-reg name and executes that q-reg
as a macro. The q-reg should contain ordinary
TECO commands, not ^R mode commands. The numeric
arg to the ^] will be given to the macro which
will see it as the value of ^Y (If no argument is
specified, ^Y will be 1, but F^X will indicate that
the macro had no argument). The macro may
return values to ^R telling it which areas of
the buffer may need redisplay (see below).
If the macro is to return values, it should end
with a space - otherwise, the values might get
lost within TECO.
Example: " .,( G..K .) "
gets q-reg ..K and returns 2 values limiting
the range of the buffer in which changes took
place.
^? (rubout) deletes bacwards (-D). If FS RUBCRLF
is nonzero, rubout when the pointer is after a
CRLF deletes the whole CRLF.
ctl-rubout
deletes backwards like rubout, except that tabs
are converted to spaces and the spaces are deleted
one at a time.
^S:
<n>^S if <n> is positive, sleep for <n> 30ths of a
second. If <n> is negative, sleep until system
run time (what FS UPTIME gets) = -<n>.
<n>:^S sleep for at most <n> 30ths of a second, returning
immediately if there is any input available.
Returns the value of FS LISTEN (nonzero if
input is available).
^U display in the user-specified manner the directory of
the current default device. That is, invoke the user's
buffer display macro if any; otherwise on display consoles
display in the standard manner, but do
nothing on printing terminals. These are the same actions
TECO always takes at the end of any command string whose
last command was an E-command.
Note: if ^U is typed as the first character of a command
string, it is executed immediately when read.
^V pops the "ring buffer of the pointer". ^V when the
first character of a command string acts immediately,
resetting the pointer to the value it had before the
last time it was moved. Successive ^V's will undo
earlier changes of the pointer. Up to 8 changes are
remembered to be undone. Motion caused by the use of
^V in this manner does not get saved to be undone.
^V not the first character typed is slightly
different. It pops the ring buffer into the pointer,
and returns as its
value the number that then remains on the top. If that
returned value is put in Q..I (which is what gets
pushed on the ring buffer at the end of the command
string) you can fool TECO's top level into thinking
that the pointer was not moved by the command string
that just finished, so nothing will get pushed back on
the ring buffer (this is exactly what ^V as the first
character typed does). If TECO's top level is not in
use, the program that is running must be hacked up to
push explicitly on the ring buffer (using <n>^V)
in order for anything to appear on it.
If ^V attempts to jump out of the buffer, the pointer
is not moved, but the ring buffer is popped. A "NIB"
error happens.
:^V returns the value on the top of the ring buffer,
without popping it or changing the pointer.
<n>^V is equivalent to <n>FS PUSHPT. It pushes <n> onto
the ring buffer unless <n> equals whatever is at the
top of the ring buffer.
<n>:^V pushes <n> onto the ring buffer unconditionally.
^W pops all the way to top level,
exiting from any break-loops and not running the user
defined error handler in ..P.
^X only defined inside macro. Its value is the
first arg of the M command which called the macro.
See the F^X command for a more sophisticated
way for macros to examine their arguments.
Note: ^X typed as the first character of a command
tells TECO to type out the whole error message
associated with the most recent error. If the flag
FS VERBOSE is zero (normally true on printing terminals)
TECO normally types only the 3-letter code. Use ^X
to see the whole message if you don't recognize the code.
Note: ^X in search string is a
special char which is matched by any
character.
^X may be used in a file specification as the first or
the second filename to stand for the default first name.
^Y like ^X, only second or only arg of the M command.
If ^Y is the first char typed in in a command string,
the most recently typed command string longer
than 7 characters (not counting the 2 altmodes)
is inserted in the buffer. This is a loss
recovery procedure.
^Y may be used in a file specification as the first
or second file name to stand for the default second name.
^Z normally causes an interrupt to DDT when typed.
However, one can be given to TECO by quoting it
with ^_ , in which case it is a normal command:
with no arg, its value is a pseudo-random number.
<n>^Z inserts <n> random letters before the pointer.
Altmode terminates following text argument to
certain commands; two successive altmodes terminate a command
string in the bare TECO command loop, and begin execution of
the commands in the command string.
Execution of an altmode as a command depends on the
setting of FS NOOP ALTMODES. If the flag is >0
(old-fashioned mode), altmode acts like the ^_ command.
If the flag is negative (default mode), altmode is
a no-op. If the flag is zero (losing mode),
altmode is an error as a command.
^\ exits from the innermost macro invocation, unwinding
the q-register pdl to the level it had when the macro
was entered, and popping all iterations that started
inside that macro. Note that if Q..N is popped this
way, it's previous contents (before the pop) will be
macroed (after the pop is done). This enables macros
to arrange arbitrary actions to be performed whenever
the macro is exited, no matter for what reason.
See also FS BACK RETURN.
:^\ exits from the innermost macro invocation, without
unwinding the q-register pdl. It does pop iterations.
^] string substitution
^] is not really a command. It is a special character
that makes it possible to substitute the contents of
a q-reg into the TECO command stream at any point (such as,
inside an I or S command). ^] is processed when
TECO reads a character from the command buffer
(ie. Before anything like insertion or execution
is done to the character.). It gobbles the
next character and decodes it as follows:
^A sets the one-character flag (see below)
then reads another character and
interprets it as if it had been typed
after a ^].
^Q gobbles another character and returns
it to TECO superquoted (i.e. It will
not act as a text terminator, in a
search string, it will have no special
effect, etc.)
^R is the beginning of the name of a q-reg to
be substituted.
^S cause the superquote flag to be turned on
(see below) then read another character as in ^A
^T cause the delimiter flag to be turned off
(see below) then read another character as in ^A
^V followed by a q-register name, causes the char
whose ASCII value is in that q-register as a
number to be substituted in. That is, after
^^AU0, ^]^V0 will substitute an "A".
^X reads a string argument to the M command that
called the current macro, and substitutes it in.
^]^X pushes the current command buffer onto a
special pdl, then causes the normal macro pdl
to be popped one level (the macro pdl is
pushed onto each time an M command is executed.
It is also pushed onto by ^]<q-reg name> (see below)).
TECO will then proceed normally, reading from
what is essentially a string argument to the
current macro, until an altmode is encountered.
This altmode will not be passed to TECO, but will
instead cause the command buffer to be repushed
on the macro pdl and the special pdl to be
popped, thus restoring the state of the world.
If a real altmode is desired in a string
argument, ^]$ (dollar sign) should be used.
If TECO had been in any state other than reading
commands (i.e. Reading a string to be inserted)
then the characters read in the string argument
will be protected from being taken as text delimiters.
Thus I^]^X is guaranteed not to terminate somewhere
in the macro argument. If this is for some reason
undesirable, a ^T (see above) should be used between
the ^] and the ^X (^]^T^X). Characters are
not normally protected from being interpreted
specially in searches, etc. If this is desired,
use ^S (eg. ER^]^S^X bar will cause the file
<macro argument> bar to be selected for read,
even if the macro argument has spaces,
semicolons, etc. in it.).
If the one character flag had been on
only one character will be read as an argument
instead of an entire string.
^Y acts like ^]^X, but only one character is taken
from the previous command level. Has the same
effect as ^]^A^X. Additional ^] calls will be
chained through, with the final character com-
ming from the last command level not indirected.
(altmode) pass a superquoted altmode
back to TECO (same as ^]^Q )
^] pass an actual ^] to TECO
$ (dollarsign) pass an ordinary
altmode back to TECO (see ^X above)
. is the beginning of a q-reg name.
Multi-character q-regs such as Q..A can be substituted
with ^] just like single-character q-regs.
0-9 the current command stream (executing macro) is saved
and TECO begins reading command characters from the
contents of the specifed q-register 0-9. After all of
the characters in that q-register, which must contain
a string or buffer, have been read, reading of the
macro which contained the ^] itself will resume.
Delimiter protection and superquoting are handled as
for ^]^X. For example, I^]1 is equivalent to G1
(Note: G1 is optimized to be much faster than I^]1),
because any altmodes in the string in q-register 1 will
be delimiter protected so that they do not terminate
the I command. S^]1 will search for whatever string
is in Q-register 1. Altmodes in the string will not
end it, but ^B, ^N, ^O, etc. will have their normal
special functions. S^]^S1 superquotes the string and
makes even those characters behave like ordinary ones.
The contents of the q-register are saved so that
storing into the q-register while they are being read
does no harm.
@ @ ("indirect") causes the characters substituted in
by the ^] to be treated as if they in turn had a ^]
in front of them. Thus, after :IA.B, ^]@A will
substitute q-reg .B. After :IA.Bfoo, ^]@A will
substitute the contents of .B, followed by "foo".
I may change that if I can see an easy way.
A-Z like 0-9 (insert q-reg)
^^<char>
(ctl uparrow) has the value of the 7-bit ASCII
code for <char>.
^_ (note that in order to type this character to a
program, it must be typed twice, due to ITS hackery)
ends execution of the command string "successfully";
the TECO will log out if disowned, or return to its
superior if a ^C ended the typed-in command string.
Otherwise, or after TECO is P'd, TECO will reset all
stacks (if FS *RSET is 0), then maybe display the
buffer or dircetory (using the user's supplied macros
in Q..B and Q..G if any), and go on to read another
command string.
It is not wise to use this as a nonlocal exit from
a macro; that is what F< is for. The main use is
to restart TECO's command reading loop at the current
stack levels - useful when a user-defined error handler
wants to transfer to a TECO break loop. TECO's command
loop puts a ^_ at the end of every command string to
make sure that it gets control back when the command
string terminates. Otherwise, in a break loop, control
would return right back to the suspended program.
(Space)
Spaces around arithmetic operators are ignored.
Spaces between two values in lieu of an arithmetic
operator count as a "+", except that spaces by themselves
before a command that can use an argument do not count
as an argument.
!<label>! defines <label> for use by
O command (q.v.).
This contruct is also the standard way of putting
comments in TECO macros. It is ignored in execution.
However, quotes and angle brackets inside the label
are counted when quotes are being balanced in a conditional or
angle brackets in an iteration. This is useful, because if
the commands in a conditional need to have unmatched quotes
you can put in matching quotes inside a label to make the
whole thing balance. The same is true for unmatched brackets
in an iteration. For example:
Q1"N !"! FTYou're losing' or < Q1; EDFOO < !>! >
" starts a conditional. The character after the " gives
the condition. It is followed by conditionalized
commands, up to a matching '. If an else-clause is
desired, the ' should be followed immediately by "#,
with perhaps CRLFs, spaces, or comments (see "!") in between,
followed by the contents of the else-clause, followed by
another '. A conditional may return a value.
The conditionalized commands must be balanced as to quotes.
If some commands contain unmatched quotes, place extra quotes
inside a label (see "!") to balance them out.
The argument to the conditional is normally gobbled up by
the conditional, and the first conditionalized command
receives no argument; see F" for a variant conditional
that passes the argument along instead.
FS STEPMAC will be processed on entry to a successful
conditional.
The conditions that now exist are:
Char: Condition succeeds if numeric arg to " is
A the ASCII code for an alphabetic character.
B the ASCII code for a delimiter character
C the ASCII code for a non-delimiter character.
D the ASCII code for a digit.
E zero.
G positive.
L negative.
N nonzero.
U the ASCII code for an "upper-case" character
(anything other than 140 through 176 octal).
Any condition can be reversed with a ":"; 0:"E fails.
The delimiter characters are those characters which
are specified as delimiters by the contents of q-reg
..D. Initially, q-reg ..D is set up to specify that all
non-squoze characters are delimiters, but the user can
change that by setting q-reg ..D.
Squoze characters are letters, digits, ".", "%" and "$".
Conditionals operate by skipping the text up to the
matching ' if they fail, and doing nothing if they
succeed. If the ' terminating a failing conditional is
followed by "#, they will be skipped as well. If the
conditional succeeded, they would be executed - and "#
is really a conditional that always fails.
A special kind of conditional that returns a success or
failure code can be obtained by putting a ' after the ",
as in "'E. This kind of conditional does not skip any code.
Instead, it just returns -1 for "success" and 0 for "failure".
Such conditionals are useful because it is easy to and or
or them together and then test the result.
For example, an expression whose value is the signum of
the number in q-reg 0 is: Q0"'L-(Q0"'G)
# exclusive or (an arithmetic operator).
$ (dollar sign) the old lower-case edit mode:
"-1$" is the same as "-1F$/" (first dollar, then altmode)
"0$" is the same as "0F$" (first dollar, then altmode).
"1$" is the same as "1F$". For more info, see the
"F$" command (that's dollarsign, not altmode).
%<q> increments the number in q-reg <q> by 1,
and returns the result as a numeric value.
Meaningless if the q-reg contains text.
& logical and (an arithmetic operator)
' terminates a conditional (see ").
This character is actually a no-op when executed.
It is for the " to search for if the condition fails.
(,) fill usual role of parentheses in arithmetic calculations.
However, they are more general in that not merely arithmetic
operations but arbitrary commands can be enclosed within them.
The value within the parentheses is simply the value returned
by the last command before the close. If the open was
preceded by an arithmetic operator, arithmetic is immediately
done on that value. Otherwise, the close merges the values
from inside the parentheses with the values saved by the open.
Thus, 1,(2) and 2(1,) are both equivalent to 1,2.
The colon and atsign modifier flags are also merged in that
the open saves them and clears them, and the close restores
and merges them: they will be on after the close if either
they were on before the close or they were on after the open.
Parentheses can also be used where a q-register name is called
for; the value returned by the last command before the close is
used as the "contents" of the q-register. This construct is
allowed only with commands that only examine the q-register,
not with commands that store into it (since there is no place
to store into). See the Q command for this.
See also F( and F) for variants of these commands.
* multiplication (an arithmetic operator).
Note that in TECO there is no operator precedence.
Evaluation of arithmetic operators is left-to-right.
+ addition (an arithmetic operator).
, separates arguments for commands taking two numeric arguments.
Doesn't affect the colon and atsign flags.
- subtraction (an arithmetic operator).
. equals the number of chars to left of the pointer.
..n Q-registers
..0,..1,..2
"^P" sort puts its 3 arguments into these q-regs.
These q-regs are also used by "F^A".
..A holds the string to be used to represent the cursor
in standard buffer display. Initially "/\" on displays,
"^A^B" on Imlacs (looks like an I-beam), and
"-!-" on printing terminals (of course, TECO's default is
not to display the buffer on printing terminals unless
FS TTMODE is set).
In the cursor, backspaces always really backspace
and all other control characters are treated as non-spacing
characters.
..B holds the user buffer display macro.
After each command string whose last command was not
an E-command, TECO does "normal buffer display", as follows:
if ..B is 0, as it initially is, the default is:
on graphics devices, do "standard buffer display";
on printing terminals, do so only if FS TTMODE is set;
otherwise do nothing. For details of standard buffer
display, see "@V".
If q-reg ..B is nonzero, TECO simply macroes it. Normal
buffer display in this case consists of whatever that
macro happens to do.
Q-reg ..H and flags FS ERRFLG and FS ERROR will contain
information about the command string that just ended.
If either Q..H or FS ERRFLG is nonzero, there is text
on the screen that should not be immediately covered over.
The buffer display macro should check ..H and not display
if it is nonzero. FS ERRFLG need not be checked, since
if -1, it will automatically cause all
typeout on the first line of the screen to be ignored
on displays. This is the right thing if the buffer display
macro doesn't wish to worry about errors. If it is
desirable to write on the first line and overwrite the
error message, just zero FS ERRFLG.
..D holds the delimiter dispatch table, which tells several
commands how to treat each of the 128 ASCII characters.
These commands are FW, FL, "B, "C and the special search
character ^B. The treatment of the character with ASCII
code <n> is determined by the values of the characters
in positions 5*<n>+1 and 5*<n>+2 in the delimiter
dispatch table.
The first of the dispatch characters says whether the
character <n> is a delimiter. The dispatch character
should be " " for a delimiter and "A" otherwise.
This dispatch character is used by FW, "B, "C and ^B.
The second dispatch character describes the character's
syntax in LISP. The possibilities are "(", ")", "/", "'"
"|", " " and "A". Each says that the character <n> should
be treated by FL and @FW as if it were an open, a close,
a slash, etc.
Initially, the first dispatch character is "A" for squoze
characters (letters, digits, "$", "%" and "."), and
" " for all others. The second dispatch character is set
up to reflect the default LISP syntax definitions as closely
as possible.
The delimiter dispatch must be at
least 640 characters long so that every character has
a dispatch entry. ..D should always contain a buffer
or a string; if it holds a number an error will result.
..E holds the output radix for = and \. Initially decimal.
Negative radices work - somewhat. If the radix is 0 or 1,
the next attempt to use it will change it to decimal
and also cause an error "..E".
..F holds the ^R secretary macro. If nonzero,
it will be macroed every (FS ^RMDLY) characters
while ^R mode is in use. More precisely, the counter
FS ^RMCNT is decremented each time through ^R's main
loop, and if it becomes 0, it is reset from FS ^RMDLY
and ..F is macroed. ..F is also macroed whenever the
outermost level of ^R mode is exited (but not when
inner recursive invocations of ^R are exited).
When ..F is macroed because ^R is being exited, the
FS ^RMODE flag will be 0; otherwise it will be nonzero.
If you are using ..F to save the buffer in a file,
then when you temporarily bind the buffer or put strange
crud in it, you should also bind ..F to 0 to prevent the
buffer from being saved while it is meaningless. Do not
bind FS ^R MDLY, though; then, if the time to run ..F
comes up while in this state, TECO will make sure to run it
as soon as it becomes nonzero again.
..G holds the user-specified directory-display macro.
Whenever TECO wants to display the directory in the
usual manner (that is, when ^U or E^U is executed or
at the end of a command string whose last command was
an E-command), if this q-reg isn't zero TECO will simply
macro it (otherwise, TECO has defaults - see "^U").
When that is done, q-reg ..H will contain useful info.
..H is the "suppress display" flag. It is set to zero at the
start of each command string, whenever the screen is
cleared. It is set nonzero when any typeout or display
takes place, except for error message typeout.
TECO's default is not to display the buffer if this q-reg
is nonzero at the end of the command string. User buffer
and dir display macros should also look at this flag.
If ..H is nonzero on entering or returning to ^R, ^R will
wait until a character is typed in (and executed, unless
it is a space) before allowing any redisplay.
..I at the start of each command string,
.'s value is saved in this q-reg.
At the end of each command string, Q..IFS PUSHPT is done.
Those actions are what enable the ^V command to work.
..J initially 0, if this q-reg contains a string that string
will appear on the screen just above the echo area, on
the same line that --MORE-- sometines appears on. The
--MORE-- will still appear, following the ..J string,
if it is appropriate. The displayed string is not
updated immediately when ..J is changed, but rather at
the next opportunity for redisplay of the buffer or
the next time typeout reaches the bottom of the screen.
It is possible to put a buffer in ..J but that has the
problem that TECO will not always be able to detect it
when the buffer's contents change, and thus will not be
able to update the screen when it should.
If the string in ..J is too long, it is truncated to make
sure that the --nn%-- or --MORE-- can fit.
If recomputing ..J when you want it to change is too
inconvenient, you can arrange for ..J to be recomputed when it
is about to be displayed. See FS MODE CHANGE.
..K each ^K or ^W command in ^R mode puts the deleted text
in this q-reg so it can be reinserted if desired.
..L whenever TECO is started, this q-reg is executed.
Also, after an EJ, the macro loaded into ..L is run.
When a TECO dump file is made with @EJ, ..L should
contain a macro to do whatever must be done when the
file is loaded back in. However, since that macro would
be re-executed if TECO were G'd afterward, it should
replace itself with something innocuous that just
resets the terminal-related flags.
If a ..L macro can exit, it should do so with a ^_ to
start up the TECO command reading loop. A CNM error
will occur if the ..L macro tries to return any other way.
..L should no longer be used for resetting
terminal-type-dependent options. Use FS TTY MACRO for that.
..N this q-reg is special in that whenever it is popped by
automatic unwinding of the q-register pdl, the previous
contents are macroed after the pop.
Thus, it is possible for a macro to set up an
action that will be performed when the macro is exited,
no matter what causes it to be exited, by pushing Q..N
and putting the commands for that action in Q..N. For
example, [0 .U0 [..N :I..N Q0J saves . in such a
way that it will always be restored. That string,
unfortunately, has a timing error in that a ^G-quit
after the [..N will find an inconsistent state. The
remedy is to use the FN command which is the same as
"[..N:I..N": [0 .U0 FN Q0J
Within a macro that has already set Q..N up in this
way, the easiest way to add another action to be
performed is to append to ..N using
:I..N^]^S..N<new-stuff>.
Note that popping Q..N explicitly with ]..N does not
macro it.
If you wish explicitly to pop ..N and macro the old
value, the way to do it is "-FS QPUN". "M..N]..N"
has the disadvantage that when ..N is executed it is
still on the q-reg pdl; that may make it execute
improperly and also is a timing error.
..O this q-reg is defined to hold the current buffer. That is,
all the commands that use "the buffer" use whatever
buffer happens to be in Q..O at the time. An attempt
to put a string or number in Q..O causes an error.
..P holds the user-defined error-handler macro, if any.
Whenever an error occurs that is not caught by an errset,
this macro will be invoked. If it is 0, TECO will
instead print out the error message and set up for "?"
in the normal manner.
The executing command string will have been pushed on the
macro pdl, so FS BACKTRACE can be used to examine it.
Also, the arguments will have been saved with "(" so that
they can be examined with ")F(=".
FS ERROR will contain the error code for use with
FE or FG in obtaining the error message.
Note that the error handler is invoked for quits and when
TECO is restarted, as well as after errors; at those
other times FS ERROR will be zero.
If the error handler prints an error message in the main
program area of the screen, it may wish to allow buffer
display to occur as usual but prevent the error message
from being overwritten by it. Setting Q..H to zero
permits buffer display, and setting FS ERRFLG to minus
the number of lines of error message preserves them.
The FG command takes care of this automatically.
The error handler can return to the erring program with
")^\" or "F)^\" (return whatever you like, but make sure
to close the parentheses somehow). However, do not expect
the command that signalled the error to be retried.
To abort the entire computation which got the error, the
correct thing to do is FS ERR THROW. This will return to the
innermost error catch (:@< ...>) or ^R level. If there is
none of those, it will return to the top level of TECO.
You may also use F; to return to a catch that was
made at a higher level, or use ^W to pop out to TECO's
top level loop.
To make a break loop, just do a ^_ which will transfer
to TECO's command string reader.
If an error happens while the error handler is being entered,
in order to prevent an infinite error loop TECO does an
automatic ^W command to pop all stacks and prints "error
entering error handler". Stack overflow for any reason is
likely to cause this since the error handler requires stack.
Any error in the error handler is likely to cause a series of
recursive errors, fill the stack, and cause this response.
..Q holds a q-vector which serves as the symbol table for TECO
variables, such as QFoo accesses. The symbol table is
in the format that FO likes. Initially, the q-vector in
..Q has only one element, which contains 2, the number of
words per symbol table entry. See FO and Q for more details.
..Z initially holds the same thing as ..O (the initial buffer),
on the assumption that your main editing will be done in it,
so that if you accidentally leave something else in ..O
you can do Q..ZU..O to recover and not lose all your work.
/ division (an arithmetic operator).
0-9 a string of digits is a command whose value is a number.
If it is not followed by a ".", the normal input radix
(the value of FS IBASE, initially 8+2) is used.
If the number ends with ".", the radix used is
the value of FS I.BASE, initially 8.
An attempt to type in a number too large for a 36-bit
word to hold will cause a "#OV" error, unless the radix
is a power of 2.
: used before certain commands,
modifies function of that command
in a way described separately for each such command.
Arithmetic operators and comma do not affect the
colon flag. Parens save it just like arguments, and
don't deliver it to the commands inside the parens.
Commands that don't return values always turn it off;
commands that do, either ignore it or use it and turn it off.
; does nothing if arg<0. Otherwise
sends command execution to char
after next > (see < description).
If no arg, uses value returned by
last search (see S) as arg.
:; like ;, but with the opposite condition:
end iteration if arg is <0, or last search succeeded.
@; like ;, but exit iteration if arg is EQUAL to zero.
:@; like ;, but exit iteration if arg is NOT EQUAL to zero.
< begin iteration. Commands from here to the matching >
are executed over and over, until a ; command decides to exit
the iteration. It does so by scanning forward, counting <'s
and >'s seen, until an unmatched (since the ;) > is passed.
Because of the way ; works, commands inside iterations
following a ; must be balanced as to angle brackets. If a
command contains an unmatched bracket, you can use an opposite
bracket inside a label to balance it out.
Within the iteration, the sequence !<!> can be used to mean
"jump to the beginning of the iteration." The !<! is needed
to avoid confusing any ; commands earlier in the iteration.
It is an error if the iteration remains unterminated
at the end of the macro level it began on.
Within iterations, failing searches do not cause
errors, unless FS S ERROR is nonzero (as it is in EMACS)
to disable this "feature".
<n>< iterates <n> times (or until a ; command exits).
The !<!> construct must not be used in such an iteration
since, if the count has run out, it will not do its job.
Use !<!@> if you want to jump to the beginning without
decrementing the count.
<m>,<n><
ignores <m>.
:< begin errset. This is like < except that errors
occurring inside it are caught and will return after the >.
TECO will not print any error message nor run the error
handler in ..P. Instead, the error message string will be
returned as the value of the ">" which ends the errset.
If the errset returns normally (no error) the value is 0.
The canonical application for errset is 1:< EDFOO BAR > which
deletes FOO BAR if it exists but avoids any problem if the
file does not exist.
TECO's built-in error messages all start
with a 3-letter code that says what kind of error it is;
use a F~ to compare the error message string against a
specific prefix.
Note also that :< iterates like <. Perhaps you want 1:< ?
Errsets do not prevent failing searches from erroring
(luckily), and prevent any iterations outside them from
doing so. An iteration inside an errset will still prevent
searches from erroring inside it despite the errset.
Of course, to really win, you should set FS S ERROR.
An errset has no power through a call to ^R or through an
error catch (:@<). The innermost errset, ^R, or error catch
is what determines how an error will be processed.
:@< begin error catch. An error catch specifies a place for
control to return to after an error has been processed (error
message printed or error handler in ..P run). It differs from
an errset (:< with no @) in that the errset grabs control
without letting the error message be printed. The canonical
application for an error catch is in a command loop which
allows the user to give many different commands. An error in
one of the commands should be reported as usual, but the error
should not cause the command loop to be exited. Every call to
^R implicitly contains an error catch. Note that :@< iterates
just like <. If you want it to execute only once, do 1:@<.
The command FS ERR THROW is a way to return control to the
innermost error catch (where ^R levels count as error catches).
The value returned by the error catch will be 0 if it was
exited normally, by falling through the end. If FS ERR THROW
was used to exit, then the value will be the argument given to
FS ERR THROW.
= is for printing numbers:
<n>= types out <n> in the current output radix, and a CRLF.
The output radix is kept in q-reg ..E . It is initially 8+2.
<m>,<n>= types both <m> and <n>, with a comma between.
:= is like = but omits the CRLF.
@= is like = but types in the echo area. @:= also works.
> end of iteration, errset or catch (see "<", ":<", "F<").
@> end of iteration, etc., except that the iteration count
is not decremented. !<!@> is a good way to jump back to
the beginning of the iteration without decrementing the count.
? if this is the first char input after
typeout of an error message from TECO
several command chars before the one
causing the error will be typed.
Otherwise, enter trace mode, or, if in trace mode
already, leave trace mode.
When in trace mode all command
chars are typed out as they are executed.
Trace typeout never uses the first line so that
error messages won't wipe it out.
The flag FS TRACE is nonzero when in trace mode.
:? leaves trace mode whether in it or not.
@ is a modifier command which alters the action of
the following command (except for a few commands which
ignore it and pass it on to the next command).
Many commands which take string arguments interpret
the @ modifier to mean that the first character after
the command should be used as the string delimiter,
instead of Altmode. But not all string argument commands
do this, so you must check the individual command.
The older form of the @ command is the ^ command,
so most old TECO programs will contain ^ instead of @.
^ was changed to @ because it could be confused with control
characters.
A if no arg, append next page of
input file to current contents of
buffer, i.e., like "Y" only don't empty buffer first.
If virtual buffer boundaries are in use, the appended
text goes just below the upper virtual boundary.
Does not close the input file.
<n>:A appends <n> lines of the file (but won't append beyond
a page boundary). Uses the same conventions for throwing
away padding as "Y" does. Does not close the input file.
@A appends all the rest of the file. A cross between
"A" and "@Y". Closes the input file.
<n>A value is the 7-bit ASCII value of char arg chars
to the right of the pointer. Note that
"0A" is the character immediately to the left of
the pointer and "-<n>A" is the character <n>+1
characters left of the pointer. If .+<n>-1 is not
within the bounds (real or virtual) of the buffer, a
"NIB" error occurs.
<m>,<n>A
is like <n>A except that when <n>A would cause a
"NIB" error, <m>,<n>A will return <m>. Thus,
13,1A will return 13 iff the pointer is either at the
end of the buffer or before a carriage return.
B normally 0. Actually, the number of the first character
within the virtual buffer boundaries - but that will be
the first char in the buffer (char number 0) unless you
have used FS BOUND or FS V B to change that.
C moves in the buffer relative to pointer:
<n>C move pointer <n> chars to the right (1 char, if no arg).
If that's out of the buffer, a "NIB" error results.
:C like C, but returns -1 ordinarily,
or 0 if C without colon would cause an error.
:C is to C as :S is to S.
D delete arg chars to right of pointer.
If arg<0, delete to left of pointer.
"E" commands
E is the prefix for most operations on files.
E^U<dir>
displays in the usual manner the directory of the
device specified in the string argument, or the default
device. More precisely, reads the string arg and sets
defaults, then does "^U".
E?<file>
tries to open <file>, and returns 0 if successful.
Otherwise, the value is the system error code which
describes why the file cannot be opened.
In any case, the file does not stay open, and the open
input file if any is not interfered with.
E_<old><new>
makes a copy of the file <old> and names it <new>.
I/O is done in ASCII block mode. The currently open
input and output files are not affected. :E_ is similar but
transfers the date of the input file to the output file.
@E_ puts the real filenames of the input file into the
defaults before reading the output file name, making it easy
to preserve the version number.
EC close the input file, if any. This should always be done
whenever an input file is no longer needed; otherwise, one
of the system's disk channels will be tied up.
@Y, EE and EX automatically do an EC.
All other input operations always leave the input file open.
ED<file>
deletes <file>.
:ED deletes the currently open input file (ITS only).
EE<file>
like infinity P commands then EF<file> and EC.
EF<file>
files output accumulated by PW and
P commands with the name <file>. <file> may not contain
a device or SNAME; they must have been specified when
the file was opened (with EI or EW) and may not be changed.
:EF files the output without renaming the output file.
EG is a semi-obsolete command for getting random info.
It inserts in buffer on successive lines
the current date (as YYMMDD),
the current time (as HHMMSS),
TECO's current sname,
TECO's default filenames for E-commands,
the real names of the file open for input
the date in text form,
a 3-digit value as follows:
1st digit = day of week today (0 = Sunday)
2nd digit = day of week of 1st day of year
3rd digit should be understood as binary:
4-bit = normal year, and after 2/28
2-bit = leap year
1-bit = daylight savings time in effect.
(this line is blank on Twenex)
and the phase of the moon.
There are better ways to get most of these things:
FS FD CONV, FS D FILE, FS D SNAME, FS I FILE.
EI opens a file for writing on the default device.
The filenames used will be "_TECO_ OUTPUT".
When the output file is closed, it will normally be
renamed to whatever names are specified. However, if
the TECO is killed, or another output file is opened,
anything written will be on disk
under the name "_TECO_ OUTPUT_"
:EI like EI, but uses the current filename defaults
instead of "_TECO_ OUTPUT". This is useful for opening
on devics which do not support rename-while-open
fully, such as the core link. Use :EF to close the file
without renaming it.
@EI like EI, but opens an old file in rewrite mode
if there is one, rather than creating a new file
in all cases. Together with FS OFACCP and
FS OFLENGTH this can be
used to update an existing file in arbitrary ways.
However, what you really want to use is:
@:EI like @EI but uses the default filenames
rather than "_TECO_ OUTPUT".
EJ<file>
restores the complete environment (q-reg values,
buffer contents, flag settings, etc) from the
specified file, which should be in the format
produced by @EJ. This restores all q-regs, buffers,
and flags to what they were when the file was
dumped. Exception: pure (:EJ) space is not changed,
nor is FS :EJPAGE. After loading, TECO restarts itself,
which implies that if a nonzero value was
loaded into Q..L, it will be macroed.
This is intended to be used in init files, for
loading up complicated macro packages which would
take a long time to load from source files.
If the file isn't a dump file, or was dumped
in a different TECO version, an "AOR" error occurs.
@EJ<file>
dump all variable areas of TECO on the file open
for writing (it must already be open), and file it
under the specified filenames. One should not
write anything in the file before doing "@EJ".
Files written with @EJ can be loaded into a TECO with
the EJ command, or they can be run as programs directly,
in which case they will bootstrap in all the constant
parts of TECO from the canonical place:
.TECO.;TECPUR <TECO version>. They also contain indirect
symbol table pointers to that file, so that attempting to load
the symbols of an @EJ'd file will load TECO's symbols.
If you @EJ a file TS FOO on your home directory, then FOO^K
will always get you that environment.
:EJ<file>
inserts the specified file into core, shareable and
read-only, and returns a string pointer to the beginning
of it. :EJ assumes that FS :EJPAGE points to the lowest
page used by :EJ's, and inserts the file below that
page (updating the flag appropriately). Memory is
used starting from the top of core and
working down to page 340.
See the sections "buffers - internal format"
and "buffer and string pointers - internal format"
for information on what can go in the file.
An ordinary ASCII text file is not suitable for :EJ'ing.
A file to be :EJ'ed must, first of all, be a single
string whose length (including its header) must be a
multiple of 5120 (1K words of characters). Within that
string lives the other strings or whatever that are
the data in the file. Their format is unrestricted
except that the first thing in the file (starting after
the header for the file as a whole) should be a string
which is the file's "loader macro" which must know how
to return the data in the file when asked for it.
The loader macro should expect to be called with the
name of the desired data (as a string) as the first
argument (^X), and a pointer to the whole file (as a string)
as the second argument (^Y). The reason for passing it
the pointer to the file is so that the loader itself can
be pure (independent of the particular file containing it).
The pointer to the file, plus 4, gives a pointer to the
loader itself, if the loader wishes to examine its body.
The loader macro should return as its value the string
which is the value associated with the specified name.
If the name is undefined in the current file, the loader
should pass the request on to the loader in the next file.
The next file can be assumed to start right after the
end of the current one, so that ^Y+FQ(^Y)+4 is a pointer
to it. If there is another file, FQ of that will be
positive; otherwise (this is the last file in memory)
FQ of that will be -1.
If there are no more files, the loader should return 0.
The goal is that several files with different loader macros
should be :EJ'able in any order, and yet allow things to be
loaded out of any of them at any time.
EL display in the standard manner the directory of the
default device. This command
does not use the user's buffer display macro; in fact,
the buffer display macro might well use this command.
EM insert in buffer file directory of the default device.
On Twenex, any pre-comma arg specifies don't include author name,
and a post-comma arg is passed to the JFNS call.
EN<old><new>
renames the file <old> to have the name <new>.
The device and SNAME may not be changed; they should not
be specified in <new>.
EP<file>
does ER<file>, then bigprints file name
twice on device(s) open for writing.
EQ<from><to>
creates a link named <from> pointing to the file <to>.
devices COM:, TPL: and SYS: are understood. (ITS only)
An attempt to link to a non-disk device is an error.
ER<file>
opens <file> for input. The "Y", "A" and "FY" commands
in various forms may be used to read from the file.
As soon as the file is no longer needed (eg, if all
of it has been read), an "EC" should be done to close
the input channel. "@Y" and "EE" do an automatic "EC".
FS IF ACCESS, FS IF LENGTH, and FS IF CDATE make it
possible to get or set various parameters of the file.
<n>ER is similar but specifies open-mode <n> (actually,
<n> IOR 2). <n> should be even!! <n>=4 specifies
image mode, which makes a difference for file directories.
This is only meaningful on ITS.
1,ER<file>
opens an input file and does not change its reference date.
This is defined to work on all operating systems.
ET<file>
sets the default filenames to <file>.
:ET (Twenex only) does a GTJFN reading from the terminal, to
provide filename completion, etc. The numeric argument is
the left-hand flags for the GTJFN. The flag FS :ET MODE
controls which filenames' default values are provided for the
GTJFN.
EW<dir>
like EI but device specified by
following text string rather than by a numeric arg.
:EW<file>
like EW, but uses the specified filenames
instead of "_TECO_ OUTPUT". This is useful for opening
on devics which do not support rename-while-open
fully, such as the core link.
@EW<dir>
like EW, but opens an old file in rewrite mode
if there is one, rather than creating a new file
in all cases. Together with FS OFACCP, this can be
used to update an existing file in arbitrary ways.
However, what you really want to use is:
@:EW<file>
like @EW but allows filenames to be specified
rather than using "_TECO_ OUTPUT".
EX<file>
(Twenex only) if a file is open for output, does EE<file>,
then instructs the EXEC to repeat the last CCL type command
(load, execute, compile, debug).
EY<dir>
like EL but specified device and SNAME. On Twenex, the entire
string, if provided, is used, including wildcards, for the GTJFN.
Also, on Twenex, a numeric argument specifies the JFNS format.
EZ<dir>
like EM but etc.
E[ push the input channel, if any.
Saves the current input file and position in it, or saves
the fact that no file is open.
Useful for reading in a file without clobbering any
partially read input file.
Note: for this and the next
three commands ("E]", "E\", "E^"),
the file open for input must be
randomly accessible (=DSK). The one
open for output need not be.
FS PAGENUM and FS LASTPAGE are saved by E[
and restored by E].
E] pop the input channel.
If any input file was open, the rest of it is flushed.
Further input will come from the file that was popped.
(see "E[".)
E\ push output channel.
(see "E[".)
E^ pop output channel.
If an output file is open, it is closed without being
renamed, so it is probably filed as "_TECO_ OUTPUT".
(see "E[".)
"F" commands
F further decoded by the next character as follows:
F^@:
<m>,<n>F^@
returns 2 values, which are <m> and <n> in numerical
order. Thus, "1,2F^@" ans "2,1F^@" both return 1,2.
"<m>,<n>F^@T" is the same as "<m>,<n>T" except that
the former will never cause a "2<1" error.
<n>F^@ returns, in numerical order, 2 args that delimit a range
of the buffer extending <n> lines from the pointer.
Thus, "<n>F^@T" is the same as "<n>T".
<n>@F^@
is like <n>F^@ but treats in CRLFs, not just CRs.
F^A:
<m>,<n>F^A<q>
this command scans the range of the buffer from <m> to <n>
using the dispatch table in q-register <q>. That is, each
character found in the buffer during the scan will be
looked up in the dispatch table and the specified actions
will be performed. The dispatch table should be a string
or buffer with at least 128*5 characters in it -
5 for each ASCII character. Each
character seen has its ASCII code multiplied by 5 to
index into the table, and the 5 chars found there are
executed as TECO commands. When that is done, the char
that was found in the buffer is in Q..0 as a number,
point is after the character if forward, before if backward,
Q..3 holds the dispatch table that was in use (so that
the dispatch commands can change it if they wish) and
Q..2 holds the end of the range to be scanned. For forward
scans, it is in the form of the distance between the end of
the range and Z; for backward scans, it is the distance
between the end of the range and B. Thus, deleting
or inserting characters never requires changing Q..2.
The use for changing Q..2 is moving the end of the range -
for example, stopping the scan early (do ZU..2).
Nothing forbids the macro to change point - that is a fine
way to skip over characters that are "quoted" by others.
For efficiency, if the first of the 5 chars
in the dispatch table is a space, the 5 are not macroed.
Instead, the second character, minus 64, is added into
Q..1, and the third is specially decoded. " " means no
action; this feature makes to easy to skip over most
chars, keeping track of horizontal position. Other
permissible third characters are "(" and ")".
Their use is in counting parens or brackets.
"(" means that if the scan is backwards and Q..1 is
positive, the scan should terminate. ")" means that if
the scan is forward and Q..1 is negative, the scan should
terminate. If an open-paren-like character is given
the dispatch " A( " and the close is given " _) ",
the same dispatch table may be used to find the end
of a balanced string going either forward or backward.
"F^A" may be given 0 or 1 arg - it turns them into 2 the
way "K", "T", etc. do.
<m>,<n>@F^A<q>
the atsign modifier causes the scan to go backwards.
<m>,<n>:F^A<q>
scans like F^A but expects its dispatch table to be a
q-vector containing string pointers. As with ordinary F^A,
to each ASCII character there corresponds a word of the
dispatch table, but this word should normally contain a
pointer to a string to be executed when the character is
seen. Thus, you can macro strings longer than 5 characters
without having to use up lots of q-registers to hold them.
Alternatively, the dispatch table word may contain five
characters starting with a space, which are interpreted as
in an ordinary F^A. Thus, simple characters that need only
to be skipped over are no slower than in an ordinary F^A.
The use of q-registers ..0, ..1, ..2 and ..3 is just like
that in ordinary F^A.
F^B:
<ch>F^B<string>
searches for the character <ch> in <string>. <ch> should
be the ASCII code for a character. If that character
does not occur in <string>, -1 will be returned. If the
char does occur, the value will be the position of its
first occurrence (eg., 0 if it is the first char).
<pos>,<ch>F^<string>
is like <ch>F^B but searches starting at position <pos>
in the string. If no occurrence is found past there, the
value is -1.
@F^B<string>
searches the buffer from point forward for a character
NOT belonging to <string>, and then returns
.,<address of that character>. If such a character is not
found, .,Z is returned.
-@F^B<string>
searches the buffer backwards from point for a character
NOT belonging to <string>, and then returns
<address of that character>,<point>. If no such character
is found, B,. is returned.
<x>,<y>@F^B<string>
searches the buffer from <x> to <y> (which can be either
forward or backward) for a character NOT belonging to
<string>, and then returns .,<address of character> or
<address of character>,., whichever puts the smaller
value first.
@:F^B<string>
is like @F^B with no colon except that it searches for
a character which IS a member of <string>. It takes the
same sorts of arguments that non-colon @F^B takes, and
returns the same sorts of values.
F^E<string>
replace <string> into the buffer at point. Replacing
means inserting, and deleting an equal number of
characters so that the size of the buffer does not
change. The advantage of this command over
"I<string> FKD" is that the gap need not be moved.
<n>F^E<string>
replaces <string> in at <n>. Point does not move.
Like ".( <n>J F^E<string> )J".
<n>:F^E<q><string>
replaces <string> into the string or buffer in q-reg <q>
starting at the <n>'th character. This is the only way
that the actual contents of a string can be altered,
although other commands copy pointers to strings, or
create new ones. If this command is done, it may be
necessary to sweep the jump cache (see "F?") if the
string being altered might be a macro that might
contain "O" commands.
F^F: F^F is the forward-only S-expression parser.
<s>,<e>F^F
parses LISP s-expression from the starting value of point to
address <e>, assuming that the state at the starting point is
<s>, and returns the state at the ending point, leaving point
there.
A "state" includes all the essential information about
the surroundings of a given spot in a LISP expression. Its
right half is the depth in parentheses. Its left half is made
up of several bits:
100,, => this spot is inside a comment.
4,, => this spot is between vertical bars.
2,, => the preceding character is an atom constituent or
slash, or is slashified, and we're not in a comment.
1,, => the following character is slashified.
Usually it is fine just to use zero for all the bits. Using a
negative number as an initial state specifies a negative paren
depth and makes all the bits zero.
Several Q-registers are set up on return:
Q..0 receives the address of the last comment-start or
vertical-bar open encountered. It is useful when you
find that the ending point is inside one or the other.
Q..1 receives the address of the last unmatched "(",
or -1 if there was none encountered.
Q..2 receives the address of the start of the last complete
s-expression (ie, its termination was passed), or -1 if no
s-expression begun has terminated.
Scanning stops either at address <e>, or when the parenthesis
depth becomes zero. Aside from this termination condition,
the depth is used only as a relative quantity, so you can
choose the initial depth to obtain the desired termination
condition, or make it far away from zero to disable the
feature.
To use F^F to move forward, choose an initial parenthesis
depth that will make it stop at the appropriate place.
To use F^F to move backward, go to the beginning of a
top-level s-expression, or the beginning of the buffer, and
scan forward to the point you are trying to move from.
The value in Q..1 or Q..2 will tell you where to move to.
To determine whether a line has a comment on it, scan from
such a known point to the end of that line (before the CRLF).
When the F^F returns, it will tell you whether that point is
inside a comment. If it is, Q..0 will address the semicolon.
:F^F is like F^F, except that it stos scanning if it passes the
start of an atom. It also stops when plain F^F stops.
It is useful for such things as making sure that an F^F
doesn't run away from you because there was a very long
s-expression where you expected an atom.
F^G:
<m>,<n>F^G<q>
Performs a local variable value swap on an EMACS-format buffer
table <q>. <m> should be the index in <q> (in words) of the
entry whose local variable values are to be swapped. <n> is
the offset within the entry of the first local variable.
The number of local variables is determined from the length of
the entry, which is the first word of the entry.
Each local variable is described by two words: the first is
the name; the second, the swapped-out value (the global one,
for the selected buffer; the local one, for other buffers).
The name of a local variable is either a string, for a
QFOO-type variable, or the :FSQPHOME of a short-name
q-register or ^R-mode character definition or FS flag.
Each swapped-out value is exhanged with the value cell of
the variable, found by looking the name up in q-reg ..Q if it
is a string, or by using it as an address if it is a number.
A number must represent a ^R character, a q-register, or an FS
flag. Suitable numbers can be obtained by pushing the
location involved and then looking at -1:FS QP HOME:
[A -1:FS QP HOME( ]A) returns the address of q-register A;
[^^@ -1:FSQP HOME( ]^^@), that of the definition of ^@;
F[^R REPLACE -1FS QP HOME(F]^R REPLACE), the code for
FS ^R REPLACE. To turn such an address into a string
containing the name of the q-register, use @FS QP HOME.
The @ and : flags make F^G transfer data only onw way instead
of swapping. @F^G copies the current values into the local
symbol table, but does not change the current values. :F^G
copies from the local symbol table setting the current values.
F^K<prompt>
is a command that reads a string argument. If the current
macro was called by another macro, without the @ flag (see @),
the string argument is read from the caller as if by ^]^X. In
this case, the <prompt> is ignored. If the current macro was
run as the definition of a ^R-mode character, or was called
with the @ flag to pretend that it was called directly by ^R,
the string argument is read by doing M*F Hook*. The
<prompt> string should be read as an argument by that macro,
which the user is responsible for defining. In addition, F^K
can be given one or two numeric arguments which will be passed
on to *F Hook*.
In either case, the string argument is returned as a string
object as the value of the F^K command.
If you like, you can make the *F^K Hook* macro exit the
macro containing the F^K in the event that the user rubs out
past the beginning of his argument. This can be done with
-3 FS BACK RETURN.
:F^K can be used by a macro to tell whether it was called from
the internals of TECO or from another macro. It returns -1
if the macro was called from the internals of TECO or was
called with @M. Otherwise, it returns a positive number.
F^R reports to ^R that completely unknown changes to the buffer
have taken place, and that ^R should not assume that any of
the information it remembers from previous display is still
valid.
<m>F^R is a no-op, to round out F^R with zero or two args, so that
you can pass to F^R any args you might have returned to ^R,
with equivalent results.
<m>,<n>F^R
reports to ^R that the range of characters <m> to <n> has
changes made in it, and needs to be redisplayed. This is
like doing <m>,<n>@V except that F^R never actually does
the redisplay; it just causes it to be done at the next
opportuntity. F^R should not be used unnecessarily. For
example, once a macro uses F^R, it cannot be used on any
buffer except the one the next ^R up is displaying.
<m>,<n>@F^R
reports to ^R that screen lines <m> through <n>, not
including <n>, need redisplay. This is used for exiting
minibuffers. It is very important that the last thing
displayed on line <n> be unchanged and still belong
on that line.
:F^R asks ^R to verify that the window in FS WINDOW is still
valid, and choose a new valid one if it isn't. This operation
is extremely fast when the window is still valid, because it
assumes that FS ^R VPOS is up to date. If you want it to
assume nothing, do a plain F^R first. Normally, the previous
window is kept if it is still valid. To insist on
re-centering point, do -1FS WINDOW first to flush the old
window.
<n>:F^R
asks ^R to choose a new window putting point on line <n> of
the window area. <n> is relative to FS TOPLINE. The old
window is never re-used. FS ^R VPOS is not depended on.
@:F^R is like :F^R, except that on a
terminal with insert/delete line capability ^R will attempt to
move text on the screen IMMEDIATELY so as to optimize
redisplay later. The number of lines up or down to move the
text is determined by assuming that FS ^R VPOS is valid.
<n>@:F^R
is like <n>:F^R, but moves text on the screen if possible.
F^S:
<m>,<n>F^S<q>
searches the buffer in <q> for a word containing <n>, starting
at word <m>. If one is found, its index is returned;
otherwise, -1 is the value. The index of one occurrence can
be used as <m> in the next call to find the next occurrence.
<m>,<n>:F^S
searches the ^R character definition table instead of a buffer.
In other respects it is like F^S.
F^X within a macro, this command returns as its values the
arguments that were given to the macro. As many values
are returned as args were given. To find out how many
there were, use F^Y.
F^Y returns a value saying how many args it was given. For
example, WF^Y returns 0; W1F^Y, 1; W1,F^Y, 2; W1,2F^Y, 3.
The : and @ flags are also indicated by bits in the value;
:F^Y returns 4 and @F^Y returns 8. 1,2:@F^Y returns 15.
The modifier flags, and the previous arguments, are flushed.
F^^<^R-char>
F^^ takes the name of a ^R-character definition, as a
q-reg, and returns the 9-bit character code for the
character. For example, F^^.^R. returns the code for
Control-., which is 256 octal.
<string>:F^^
:F^^ is used to test whether a string contains a valid short
q-register name. The string is passed as a string pointer in
a prefix argument. If the string contains a short q-register
name then the :FS QP HOME of that q-register is returned.
Otherwise, zero is returned.
F"<condition>
F" is a conditional. It works like ", except that
whereas " throws away its argument after testing it,
F" returns its argument, whether it succeeds or fails.
Thus, QA-QBF"LW'+QB implements max(QA,QB).
(a better way, though, is QA,QBF^@, before any command
which ignores a pre-comma argument).
F$ is used to read or set the status of case conversion
on input and case flagging on output, for terminals
that do not have lower case. What those features do
when activated is described below. F$ controls them thus:
with no arg, returns the value of FS CASE
and inserts in the buffer before the pointer the
case-shift char, if any, and the case-lock char, if any.
With an arg, sets FS CASE to that arg, and takes a string
argument whose 1st char becomes the new case-shift,
and whose 2nd char becomes the new case-lock.
(if the chars are the same it is only a case-shift)
(if there are no chars, you get no case-shift or -lock, etc)
the old case-shift and case-lock, if any, become normal
characters before the string arg is read. Thus, repeating
an F$ command will not screw up.
Case conversion on input:
When FS CASE is nonzero, all letters are normally
converted to the standard case, which is upper case
if FS CASE is positive; lower if negative.
The case-shift char causes the next char to be read in
the alternate case. The case-lock char complements
the standard case temporarily
(it is reset for each cmd string).
The case-shift quotes itself and the case-lock.
The "upper case special characters" which are "@[\]^_"
are not normally converted, but if one of them is preceded
by a case-shift it will be case shifted into a "lower
case special character" (one of "`{|}~<rubout>").
(note that case conversion happens during command execution
now, so that it makes sense to change modes in the middle
of a command string. However, no case conversion is done
on characters that come from macros)
(note also that it doesn't work well to have FS CASE
and FS *RSET simultaneously nonzero, for complicated reasons).
Case-flagging on output:
If FS CASE is odd, chars in the nonstandard case
(and the "lower case special characters") will
be preceded by case-shifts on typeout from the buffer.
If FS CASE is even, no flagging is done.
F( is like ( except that whereas ( returns no values,
F( returns its arguments. F( therefore facilitates
putting the same information in two places without the
use of a q-reg.
<n>F(<m>)
converts <n> feet <m> inches to inches.
F) resembles ), but whereas ) returns its arguments
combined with the values stored by the matched (,
F) returns precisely its arguments. The data saved
by the corresponding ( is discarded.
F* reads and ignores a string argument. Useful in macros
because "F*^]^X" reads and ignores a string argument
passed to the macro.
F+ clears the screen. Like "^L", but does not separate
pages in files. If only a part of the screen is in
use (FS LINES or FS TOP LINE is nonzero), only that
part is cleared. To be sure to clear the whole screen,
bind both of those flags to 0 around the F+. On
non-erasable displays such as Tektronixes, this does clear
the screen, even though TECO does not otherwise treat such
terminals as displays. On printing terminals, a CRLF is
typed.
F6<string>
returns a word of SIXBIT containing the first six
characters of <string>.
<sixbit>F6
interpreting <sixbit> as a word of SIXBIT, converts
it to ASCII which is then inserted in the buffer
before the pointer.
<sixbit>: F6
returns a string containing the characters of <sixbit>.
@F6 is an obsolete equivalent command.
F;<tag>
is a "throw", a la LISP. See "F<" below.
F<!<tag>! ... >
is a catch. If anywhere in the arbitrary code which
may replace the "..." a "F;<tag>" command is executed,
control will transfer to after the ">" that ends the
catch. If no "F;" is executed, the catch acts like
an iteration, so if the code should be executed only once,
"1F<" should be used. When a "F;" or throw happens,
all macros, iterations and errsets
entered within the catch are exited and the
q-reg pdl is unwound to the level it had at the time
the catch was entered. Example:
F<!FOO! [A FIUA QAI QA-32"E F;FOO' ]A>
reads characters from the terminal and inserts them, up to
but not including the first space, and does not modify
the q-reg pdl (never mind that this macro might be improved).
If a throw ("F;") is done to a tag that does not belong
to any catch containing it, an error "UCT" occrurs,
at which time nothing has been unwound.
The ">" ending a catch will return 0 if the catch was
exited normally; if it was thrown out of, the argument
given to the throw will be returned.
Note that case is not significant in the F; or in the F<.
:F< is an errset and a catch at the same time!
Amazing what happens when your program works
by simply examining a bunch of flags!
F= does an ordered comparison of strings.
If "F=" has numeric args, they specify the range of buffer
to be used as the first comparison string. Otherwise,
the "=" should be followed by the name of a q-reg which
should hold the first comparison string.
The second comparison string should follow the command as
a string argument, as for the "I" command. (the @ modifier
works just as it does for the "I" command)
the two strings are compared, and if they are equal
0 is returned as the value of the "F=" command.
If the first string is greater, a positive value
is returned; if the second, a negative value.
If the value isn't 0, its absolute value is 1 +
the position in the string of the first difference
(1 if the first characters differ, etc.).
A string is considered to be
greater than any of its initial segments.
F? mbox control; argument is bit-decoded.
No arg, or arg=0, implies arg=30 .
bit 1.1 - close gap.
May be needed for communication with other
programs that don't understand the gap.
bit 1.2 - GC string space.
Useful before dumping out, or if it is suspected
many strings have recently been discarded.
bit 1.3 - sweep the jump cache.
Necessary if a string's contents have been
altered by the F^E command, and might be a macro
that might have contained "O" commands.
Also necessary if :EJ is used after increasing
the value of FS :EJPAGE (thus replacing one
file with another in core).
bit 1.4 - flush unoccupied core.
Good to do every so often,
or if it is likely the buffer has just shrunk.
bit 1.5 - close the gap, if it is > 5000 characters long.
It is good to do this every so often,
in case the user deletes large amounts of text;
say, whenever excess core is flushed.
FA performs text justification on a range of the buffer
specified by 1 or 2 args (as for K, T, commands, etc.).
The idea is that whenever you edit a paragraph,
you use FA or a macro that uses FA to re-justify it.
The line size is kept in FS ADLINE .
A CRLF followed by a CRLF, space or tab causes a break.
So does a CRLF, space or tab as the first character
of the text being justified.
An invisible break can be produced before or after a
line by beginning or ending it with space-backspace.
CRLFs that do not cause breaks are turned into spaces.
Excess spaces that wind up at the end of a line are deleted.
Other excess spaces are retained. Thus, to win, you should
insert spaces after all ends of sentences which are at the
ends of lines, before you call FA. You might insert spaces
at the ends of all sentences, but you can presume that they
are already there, when desired, in the middle of the line.
Spaces at the beginning of a line are treated as part of
the first word of the line for justification purposes,
to prevent indentation of paragraphs from changing.
The last part-line of stuff to be justified is only filled.
Tabs prevent justification of what precedes them on a line;
to prevent filling, you must put in a break (use sp-bs).
I suggest using "FA" in the following macro:
[0 Z-^YU0
^XJ <.,Z-Q0FB.
^O?
; :0L I >
!""Make sure .'s and ?'s at end of line have spaces!
^X,Q0FA !actually justify!
]0
If you want indented paragraphs, simply indent them the
right amount when you type them in. "FA" will leave the
indentation alone. "FA" knows about backspace.
Sometimes it is desirable to put a space in a word. To
do that, use space-backspace-space.
@FA like "FA" but only fills (doesn't justify)
FB bounded search. Takes numeric args like K, T, etc.
Specifying area of buffer to search, and a string
argument like S, N, etc. The colon and atsign flags
are used as they are by other search commands.
:FB is like :S, not like :L. That is, :FB returns a
value indicating extent of success, and searches the
same range of the buffer as FB with no :.
If two args in decreasing order are given searching is
done in reverse. With one negative arg, the search is
forward, but through a range that ends at the pointer.
FC takes arguments like K and
converts the specified portion of the buffer to
lower-case. Only letters are converted.
@FC converts a specified portion of the buffer to upper case.
<ch>:FC returns the upper-case equivalent of the character whose
numeric code is <ch>, as a numeric code. Meta-bits in
<ch> are passed through unchanged.
:FC may also be given a string pointer as argument.
It returns a new string containing the upper-case of its
argument.
FD a list manipulating command whose main use is in
"<arg>FDL", which moves down <arg> levels of parens.
FD returns a pair of args for the next command.
If <arg> is positive, they specify the range of the
buffer from the pointer rightward to the first
character that is <arg> levels up;
if negative, leftward to the first character
-<arg> levels up.
FE inserts a list of TECO error messages and explanations
in the buffer before the pointer, one message per line.
<arg>FE inserts only the line describing the error
of which <arg> is the error code.
<arg> might have been returned by an errset,
or might be the value of FS ERROR .
Since error codes are actually strings, <arg>FE
is equivalent to G(<arg>) I<crlf>
@FE<errname>
returns the error code associated with the given
error name <errname>. Only the first three characters
of <errname> are used. This is useful for analysing
anticipated possible errors and recovering appropriately.
Another way to do that is to compare the first three
characters of the error code, which is a string, against
the expected ones, with F~.
:FE inserts a list of FS flag names in the buffer before
the pointer, one name per line.
FG does error processing. With no argument, it simply
rings the terminal's bell. Given the @ modifier, it
also throws away type-ahead. Given a nonzero numeric
argument (which should be s string), FG prints its
contents as an error message (obeying FS VERBOSE).
Accompanying the numeric argument with the : modifier
causes the error message to be typed at the top of
the screen (think of : FT). Unlike most commands that
do typeout, FG does not change Q..H, so that typing an
error message will not inhibit buffer display or ^R
redisplay. Instead, FG sets FS ERRFLG so that the
next buffer display will not overwrite the line(s)
occupied by the error message.
FI input one character from the terminal and return its
ASCII value. (same as vw without the v)
if the "mode" (in q-reg ..J) has changed, the new
value will be put on the screen, unless input is
already waiting when the FI is executed.
:FI similar to FI, but doesn't flush the character.
It will be re-read by the next FI
or by TECO's command string reader.
@FI is like FI, but returns a character in the 9-bit
TV character set, rather than converting it to ASCII
as FI does.
In the TV character set, the 400 bit means "meta",
the 200 bit means "control", and the bottom 7 bits
are a printing character (if < 40, it is one of the
new TV graphics, or else it is a formatting character).
Note that there exist controlified lower case letters
different from their upper case counterpart (for example,
341 octal is control lower case a).
@:FI analogous.
FJ insert the TECO job's command string as read from DDT
in the buffer. Will normally end with a CR-LF
but may be null.
FK returns minus the value of FS INSLEN; that is,
minus the length of the last string inserted by "I", "G" or
"\", or found by a search or "FW". FK is negative except
after a successful backward search, or backward "FW".
Thus, "SFOOFKC" will move to the beginning of the FOO found.
"-SFOOFKC" will move to the end of the FOO found.
See also the ^B command in this context.
"SFOOFKDIBAR" will replace FOO with BAR. See "^F".
"IBLETCHFKC" inserts BLETCH and backs over it.
FL parses lists or S-expressions:
<arg>FL a list maniulating command, that returns 2 values specifying
a range of the buffer. If <arg> is >0, the range
returned is that containing the next <arg> lists
to the right of the pointer; if <arg> is <0,
the range is that containing <arg> lists
to the left of the pointer. This command should be
followed by a command such as K, T, X, FX ...
which can take 2 args; the specified number of lists
will be deleted, typed, put in q-reg, etc.
To move to the other side of the lists, do "<arg>FLL".
The syntax parsed by FL is controlled by the delimiter
dispatch table in Q..D; the character types known
are "A", " ", "|", "/", "(", ")" and "'", and any character
can be redefined to be of any of those types.
:FL is like FL, but stops before the ( that starts the list
instead of after. -:FL stops after the ), etc.
<arg> @FL
is like "<arg>FL", but refers to <arg> s-expressions
rather than <arg> lists. An s-expression is either
a list or a LISP atom, whichever is encountered first.
"@FW" is used to find LISP atoms when necessary.
@:FL stops before the next s-expression - if it is a list,
it stops before the (, and if it is quoted it stops before
the quote.
FM:
<m>,<n>FM
attempts to move the pointer so that the cursor will
appear at hpos <n>, <m> lines below where it started out.
"FM" without the "@" modifier can move only toward the
end of the buffer. It operates by moving the pointer
downward in the buffer until either 1) the exact desired
absolute hpos and relative vpos have been reached, in
which case "FM" simply returns, or 2) the end of the buffer
is reached, which causes a "NIB" error, or 3) the line
below the desired one is reached, in which case it is
known that the desired combination of hpos and vpos does
not exist, so FM reverses its motion until it is back
on the desired line, then issues a "NHP" error.
"FM" tries to avoid leaving the cursor between
a CR and the following linefeed.
"FM" will not currently work if ^R mode has never been
entered, but it need not be in ^R mode.
The ":" modifier causes "FM" to accept any hpos greater
than or equal to the second argument as a condition for
success, rather than demanding exact equality.
The "@" modifier causes "FM" to scan toward the beginning
of the buffer rather than toward the end. The first argument
should not be positive. The algorithm
is otherwise unchanged and ":" has the same meaning
(accept any hpos >= the specified one).
FN is the same as [..N :I..N. It is needed because it
elminates the possibility of a ^G-quit between the
push and the insert. If such a quit happened, the
previously set up undo action would be performed
twice instead of once, and that might have bad results.
To perform the opposite action - pop and macro Q..N -
just do "-FS QPUN".
The ..N macro has no effect on the value(s)
returned by the macro that set it up.
The atsign flag allows the user to specify a string
delimiter, as with the I command.
FO<q><name>
binary-searches tables of fixed-length entries.
It is intended for searching and constructing symbol tables.
<q> should be a q-vector or pure string containing
the table, and <name> the item to search for.
The table's data must be an integral number of words.
The first word of the table must contain the number of words
per table entry; the rest of the table is then divided into
entries of that size. The first word of each entry should be
the entry's name, as a TECO string pointer. This name is what
FO will match against its string argument. The second word
of each entry should be the value; the use of any extra
words is up to the user. The entries' names must always be
kept in increasing order, as F~ would say, or FO's binary
search will lose. Also, they should not contain leading,
trailing, or multiple spaces, or any tabs. Their case is
ignored.
FO, without colon, will return the value from the entry if
the name is found; otherwise, an UVN or AVN error results.
@FO allows only exact matches. Abbreviation is not allowed.
:FO returns the offset (in words) of the entry found;
if the name is not found, :FO returns minus the
offset (in words) of the place the name ought to be inserted
in the table. The offset of the first entry in the table is
1, to skip the word in the front that contains the entry
size.
<arg>FO is like plain FO except that if the name is
undefined <arg> is returned as its "default value".
Ambiguous names still cause errors.
Here is a macro that uses FO to create variables that
can then be used with the Q<name> construction:
[0 :I0 ! Get variable name in Q0 !
! Find it, or where to put it if not found !
[1 :FO..Q 0U1
Q1"L ! If not found, put it in !
Q..Q[..O ! Symbol table lives in ..Q !
-Q1*5J 10,0I 10R ! Make space at right place !
! Install string containing variable name !
Q0,.FSWORD'
If this macro is put in QV, then MVFoo will create
a variable named Foo.
If the table is a pure string, the data must start on a word
boundary, which means that the string's header must start in
the second character in its word. In addition, the pointers
to the entries' names are taken to be relative to the table
itself. That is, the "pointer" should be an integer which,
when added to the TECO string pointer to the table, should
give a TECO string pointer to the name of the entry.
FP:
<obj>FP returns a number describing the data type of the
object <obj>. The possible values are (in DECIMAL):
-4 A number, not even in range to point into
pure or impure string space.
-3 A number that is in range for pure string space
but does not point at a valid string header.
-2 A number that is in range for impure string space
but does not point at a valid string header.
-1 A dead buffer.
0 A living buffer.
1 A Q-vector.
100 A pure string.
101 An impure string.
FQ<q> returns the number of characters in q-reg <q>
(-1 is returned if the q-register contains a number).
FR tells TECO to update the displayed mode from q-reg ..J,
provided it has changed, and no terminal input is available.
:FR erases the mode line.
FS reads in a flag name as a text argument.
Flag names may be any length, but only the
first six characters are significant.
Spaces are totally ignored. Only enough
of the flag name to make it non-ambiguous is required.
However, in programs, abbreviation should be minimized.
The result of the FS is the current value of the flag.
If an argument is given to the FS and the flag can be set,
is then set to that value.
If a flag can be set, to make it's value the second operand
of an arithmetic operator put the FS command in parens.
Otherwise, FS will think it has an arg and set the flag.
Flags labeled "read-only" do not require that precaution.
Flags currently implemented are:
FS % BOTTOM specifies the size of the bottom margin as a
percentage of the number of lines being displayed.
Initially 10. Rather than let the cursor appear
inside the bottom margin, TECO will choose a
new buffer window - unless the bottom of the
buffer appears on the screen already.
FS % CENTER specifies where TECO should prefer to put the
cursor when choosing a new window, as a
percentage of the screen from the top.
Applies even if the end of the buffer appears
on the screen - in fact, the purpose of this
variable is to make sure that when you go to
the end of the buffer some blank space is provided
to insert into without total redisplay.
Initialy 40.
FS % END specifies (as a percentage of total size) the
size of the area at the bottom such that TECO
should never choose a new window putting the
cursor in that area. Initially 30.
FS %OPLSP (read only) nonzero if the terminal is inferior
to a LISP job (actually, if the superior has set the
%OPLSP bit in the .OPTION variable of the TECO).
FS % TOP the size of the top margin. Analogous to
FS %BOTTOM. Initially 10.
FS %TOCID (read only) nonzero if the terminal can insert
and delete characters. This flag reflects
the bit with the same name in the terminal's
TTYOPT variable, and it is updated whenever
TECO is restarted or FS TTY INIT is done.
FS %TOFCI (read only) nonzero if the terminal can generate
the full 9-bit character set. See FS %TOCID.
FS %TOHDX (read only) nonzero if the terminal is half-duplex.
See FS %TOCID.
FS %TOLID (read only) nonzero if the terminal can insert
and delete lines. See FS %TOCID.
FS %TOLWR (read only) nonzero if the terminal can generate
lower case characters. See FS %TOCID.
FS %TOMOR (read only) nonzero if the user wants --MORE--
processing, in general. See FS %TOCID.
FS %TOOVR (read only) nonzero if the terminal is capable of
overprinting. See FS %TOCID.
FS %TOROL (read only) nonzero if the user has selected scroll
mode. See FS %TOCID.
FS %TOSAI (read only) nonzero if the terminal can print
the SAIL character set. See FS %TOCID.
FS *RSET initially 0. Nonzero suppresses automatic
unwinding of TECO's various pdls each time
through the top level loop. In other words,
when FS *RSET is non-zero, errors not caught by
errsets enter break-loops in which q-regs may
be examined (unless the user's error-handler
macro in q-reg ..P intervenes). The break-loop
may be returned from with ")^\", or thrown
out of with "^W" or "F;". The suspended program
and its callers may be examined with FS BACKTRACE.
For more info on break-loops, see under q-reg ..P.
FS .CLRMOD (normally -1) if < 0, TECO clears the screen
whenever it gets the terminal back from its superior.
If 0, that is not done
(used mainly for debugging TECO).
If > 0, screen clearing is totally eliminated,
even if requested by the program
(use this for debugging macros that try to
destroy trace information).
FS .KILMOD normally -1. If 0, FS BKILL doesn't actually kill.
FS .TYI BACK backs up the pointer FS .TYI PT by one step. Back up
the pointer n steps and then you can use FS .TYI NXT
n times to get the n previous input characters.
FS .TYI NXT is used to extract from the ring buffer of saved
type-in characters. See FS .TYI PT.
FS .TYI PT is TECO's pointer into the ring buffer of the last
60 input characters. All input characters read by
TECO are saved in this buffer, for the sake of
programs to tell the user what he typed by mistake.
This pointer is used in conjunction with FS .TYI BACK
and FS .TYI NXT, for extracting the contents of the
ring buffer. This is done with the following code:
FS .TYIPT[1 [2
< FS .TYINXT U2
do something to print the character in Q2.
FS .TYIPT-Q1@;>
Each FS .TYI NXT extracts the next character from
the buffer and advances the pointer. When the pointer
has been advanced all the way around to its original
position, the entire buffer has been printed.
After an input character is read and stored in the
buffer, FS .TYI PT is initialized to point at that
character. Though FS .TYI PT is changed by ths use
of FS .TYI NXT and FS .TYI BACK, this has no
effect on how input characters are stored.
FS :EJ PAGE is the number of the lowest page used by :EJ'd
shared pure files. Initially 256. If multlipied
by 5*1024, and then added to 400000000000 (octal),
the result is a suitable string pointer to the
last file :EJ'd. :EJ looks at this flag to
figure out where to insert the next file to avoid
clobbering the previous ones. It is an error to set
this flag explicitly to a value lower than it already
has; when it is set to a higher value, the
intervening pages are removed from the address space.
FS :ET MODE (Twenex only) controls how filename defaults are used
by the :ET command.
FS ADLINE is the line-size used by the FA command.
FS ALTCOUNT the number of 's that TECO has seen at
interrupt level.
That is, an approximation to the number of command
strings that the user has typed ahead.
Useful in user-defined buffer display macros
(q-reg ..B).
FS BACK ARGS (read-only) returns the arguments of a macro call
level up on the stack. It returns 0, 1, or 2 values,
as F^X does. The argument to FS BACK ARGS is
either the positive number of a frame counting from
the bottom (0 = the outermost frame), or a negative
number counting back from the currently executing
macro (which, by the way, has no stack frame and
cannot be referred to in either way).
FS BACK DEPTH (read only) is the number of macro call frames on the
stack. This does not include the currently executing
macro.
FS BACK PC returns the PC of a macro call frame. Which frame,
is specified as in FS BACK ARGS. The PC of a frame
is the number of the next character to be executed,
relative to the beginning of the string.
<m>,<n>FS BACK PC
sets the PC of the frame specified by <n>, to <m>.
FS BACK QP PTR (read-only) gives the level of the bottom of a
macro call frame's q-register pdl frame. This is the
level which a ^\ done in that macro will unwind to.
The macro call frame is specified as for FS BACK ARG.
FS BACK RETURN (write-only) returns control to the macro call frame
specified as for FS BACK ARG. If control left that
frame not with an M but via an exit from within a TECO
command (such as a ^R), control is returned to that
command. -1 FS BACK RETURN is equivalent to ^\.
FS BACK STRING (read-only) returns a pointer to the string or buffer
being executed by macro frame specified as for
FS BACK ARG. Sometimes a macro frame will be
executing a string constant internal to TECO. There
cannot be a string pointer to such an object, so a
byte pointer to the object (a number, according to FQ)
will be returned instead. All you can do with such
values is compare them.
FS BACKTRACE
used to see what program is running at higher
levels of the mcro pdl. The program is inserted
in the buffer, and point is put at the place
it is executing. The macro call frame is specified
just as for FS BACK ARGS.
FS B BIND is useless, but F[ B BIND and F] B BIND are useful
for pushing to a temporary buffer, or popping back
from one. F[ B BIND pushes ..O, then does FS B CREATE,
but with the extra feature that if an error happens
instead of just popping back ..O, the temporary buffer
will be killed. That is because instead of doing ]..O,
F] B BIND will be done, which is just like FS B KILL
with no argument.
If after creating a buffer with F[ B BIND you change
your mind and want to keep it, pop the previously
selected buffer off the pdl with the ] command. The
F[ B BIND will no longer be on the stack to kill the
new buffer when you return.
An argument to F[ B BIND specifies the initial size
of the termporary buffer in characters.
<n>FS B CONS returns a newly cons'ed up buffer <n> characters long.
The contents are all initially zeros, and the pointer
starts out at the beginning of the buffer. If <n> is
not specified, 0 is assumed.
When a buffer is newly created it is at the
top of memory. The closer a buffer is to the
top of memory, the more efficient it is to do
large amounts of insertion in it.
FS BCREATE is like FS B CONS U..O - the buffer is selected
instead of returned.
FS BKILL see q-reg ..O. FS BKILL is used for freeing
buffers explicitly. With an argument, it frees
the argument, which should be the result of
applying the q command to a q-reg containing a
buffer. Attempting to kill the currently
selected buffer is an error. For example,
QAFS BKILL kills the buffer in qa. After that is
done, qa still contains a buffer pointer, but it
has been marked "dead". If there were other pointers
to the same buffer in other q-regs, TECO will regard
them too as "dead" buffer pointers. An attempt to
select the buffer using one of those pointers
will result in an error.
FS BKILL may be used without an
argument, in which case it pops the q-reg pdl
into Q..O, and if the new value of Q..O is
different from the old, the old value is
killed.
FS BOTHCASE (initially 0) >0 => searches ignore case of letters.
That is, the case used in the search string is
irrelevant, and either lower or upper case will
be found.
<0 => searches ignore case of special characters
also ("@[\]^_" = "`{|}~<rubout>").
FS BOUNDARIES reads or sets the virtual buffer boundaries
(this command returns a pair of values)
the virtual boundaries determine the portion of
the buffer that most other commands are allowed
to notice. Normally the virtual boundaries
contain the whole buffer. See the B, Z and H commands.
FS BS NO LF if nonzero inhibits the LF that follows backward
motion or rubbing out, in ^R mode on printing terminals.
FS CASE like F$ (F-dollar) but neither inserts the case-shift
and case-lock if no arg, nor expects a string arg.
That is, it gets or sets the numeric quantity which
determines the standard case and whether to flag
on output.
FS CCL FNAME (Twenex only) a string, in the same format as FS D FILE,
of the jfn given in AC1 if TECO was started at the CCL
entry point; or zero if it was not or the filename has
already been read.
FS CLK INTERVAL
(write only) is the interval between real-time clock
interrupts, in 60'ths of a second. If it is zero,
real-time interrupts do not happen. Note that
real-time interrupts are not actually processed
unless/until TECO is waiting for input. Their main
use is for saving the buffer if the user walks away
from the terminal without saving it. FS IN COUNT may
be useful with real-time interupts, and FS MODIFIED.
Setting FS CLK INTERVAL postpones the next clock
interrupt to one full interval in the future.
FS CLK INTERVAL is not saved in EJ files!
FS CLK MACRO is the real-time interrupt handler macro.
If the macro types out, it must not leave Q..H set.
FS CTL MTA if negative suppresses the ^R-mode definitions of
all control-meta-letters (and ctl-meta-[, \, ], ^
and _) to make it easy to insert control characters.
This mode is convenient for editing TECO commands.
FS DATA SWITCHES
(read only) the contents of the PDP10 console switches.
FS DATE (read only) is the current date and time, as a number
in file-date format. It can be fed to FS FD CONVERT
or to FS IF CDATE.
FS D DEVICE is the current default device name, as a numeric
sixbit word. See F6.
FS DD FAST (read only) is nonzero if the current default device
is a fast device - that is, the local machine's disk.
FS D FILE is the current default filename (that ER would use)
as a string pointer. Do G(FS D FILE) to insert it in
the buffer. This flag is very useful for pushing and
popping with F[ and F]. The exact format of the string
is the SNAME, a semicolon, a space, the device name,
a colon, a space, the FN1, a space, and the FN2.
To extract specific names from the string, search for
spaces (or colon or semicolon) not preceded by a ^Q.
Note: on ITS, the default device name will never be
DSK:. It will be the name of the local machine
instead. This is so that comparison of two filenames
which have been passed through the defaults and read
out with FS D FILE will not say they are unequal
because one has device DSK: and the other the machine
name.
FS D FN1 is the current default first file name, as a numeric
sixbit word. See F6.
FS D FN2 is the current default second filename, as a numeric
sixbit word. See F6.
FS D FORCE is to be used to "force out" a buffer redisplay for
which the normal mechanism of deferring redisplay for
input and later resumption will not do the right thing
(such as, because the buffer being displayed is not
the one permanently selected). Setting FS D FORCE
nonzero has two effects: it forces the redisplay
through to completion without considering the presence
of input, and it inhibits updating the mode line.
FS D SNAME is the current default SNAME, as a numeric sixbit
word. See F6.
FS D VERSION is the current default file version number; actually,
a reflection of FS D FN2. If the default FN2 is
numeric, FS D VERSION is that fn2 as a number.
If the default fn2 is ">" or "<", FS D VERSION is
respectively 0 or -2. Otherwise, FS D VERSION is -1.
Writing -1 into FS D VERSION has no effect; writing
any other value sets the default fn2 appropriately.
On Twenex, versions are always numeric, so all values
have their usual meaning.
FS D WAIT if set nonzero causes TECO to pause slightly before
each line of output. This should give better overall
response on slow displays. It will make things much
worse on fast displays, and slightly worse on printing
terminals. This flag is initialized by FS TTY INIT
and at startup, according to the terminal speed.
FS ECHO ACTIVE if nonzero says that output has been printed in the
echo area during this ^R command, so ^R should clear
the echo area when it next wants to read a command.
Clearing is not done by the FI command; only when
the next distinct ^R command is to be read.
Commands which wish to type in the echo area and not
have their output erased can set this flag to zero.
The FG command does, when it types in the echo area.
FS ECHO FLUSH must be nonzero to enable this feature.
Otherwise, the echo area is never cleared gratuitously.
FS ECHO CHAR when a ^R command starts being executed, holds the
character that invoked it; set to -1 if anything is
typed out; when the command returns to ^R, if still
not -1, it is echoed. The command can set this flag
itself to control the echoing.
A string may be put into this flag by a macro.
Then, if the command must be echoed, the whole
contents of the string will be typed.
FS ECHO DISPLAY
(write only) like FS ECHO OUT, but outputs in display
mode, so that ITS ^P-codes may be sent. See
.INFO.;ITS TTY for details on available options.
FS ECHO ERRORS if nonzero, causes error messages to be printed in the
echo area.
FS ECHO FLUSH if nonzero, enables the automatic clearing of the echo
area after each ^R command which uses it. See
FS ECHO ACTIVE for details of how to control this.
FS ECHO LINES the number of lines at the screen bottom to be
used for command echoing. Default is 1/6
of screen size, except 0 on printing terminals. If
this flag is set to -<n>, echoing is turned off,
and there are <n>-1 echo lines. Thus,
-1FS ECHOLINES makes no echo and no echo area;
-5FS ECHOLINES makes no echo but a 4 line echo area;
0FS ECHOLINES makes echo but no echo area.
Even if echoing is off, FS ECHOOUT may be used.
FS ECHO OUT (write only) is used for outputting to the echo area.
If the argument is a number, it is taken as the ASCII
code for a character to be typed. If the argument is
a string, all the characters in it are typed.
Characters are output as they would actually echo.
Thus, sending a CR will actually do a CRLF,
and sending a ^A will print either downarrow
(in :TCTYP SAIL mode) or uparrow-A.
FS ERR same as FS ERROR if read; if written, causes an
error with the error code that is written in it.
Thus, to cause a "You Lose" error with 3-letter
code LUZ, do :I*LUZ<tab>You Lose FS ERR. Your
error message should not contain any CRLFs.
Users who wish to generate errors themselves with
the same codes that TECO uses should use TECO's
standard strings for those errors (that is,
do @FE IFN FS ERR) so that comparing FS ERROR
against @FE values will still work.
FS ERRFLG is used to signal the buffer display routine
(whether built-in or user-written) that an error
message is on the screen and should not be overwritten.
Its value is -<n> if the first <n> lines contain
an error message, or nonnegative if there is none.
If typeout is done when FS ERRFLG is negative, TECO
will not actually type the first <n> lines of it.
The <n>+1st line of typeout will appear in its
normal position, beneath the error message.
By that time, FS ERRFLG will be zero again.
FS ERROR the error code of the most recent error.
Errors caught by errsets are included.
A TECO "error code" is now just a string
containing the text of the error message.
Everything up to the first tab is the "brief" part
of the error message; if FS VERBOSE is 0, that
is all that TECO will print out. You can see if an
error was (for example) an "IFN" error by doing
F=(FS ERROR)IFN and seeing if the
result's absolute value is 4. It still works to
compare against @FEIFN, which returns the
standard string that TECO always uses for
internally-generated IFN errors.
I.T.S. I/O errors now have
messages starting with "OPNnnn" where nnn is the
I.T.S. open-failure code. Macros which used to
decode I/O errors by numeric comparison must
switch to using F=, since the strings for such
errors are consed up by TECO as needed.
FS ERR THROW (write only) return control to the innermost
error-containing command loop. This could be either
an error catch command (:@< ... >), a ^R level, or the
top level TECO command loop. This command is the
correct way for a user error handler (..P) to abort
the computation which got the error. The argument
given to FS ERR THROW is returned from the error
catch, if it happens to throw to an error catch.
Otherwise, the argument is discarded.
FS EXIT (write only) does a .BREAK 16, using the argument
to FS EXIT as the address field. See DDT DOC
for a description of what the arguments mean.
"100000." is a good value. AC 2 will contain
the address of the 7-word "buffer block"
describing the current buffer.
See the section "buffer block" at the end.
FS FDCONVERT converts numeric file dates to text and vice versa.
If there is a numeric arg, it is assumed to be
in the format for its file dates, and converted
to a text string which is inserted in the buffer.
The form of the string is dd/mm/yy hh:mm:ss.
In this case, no numeric value is returned.
If there is no arg, a text string is read from
the buffer starting at ., and . is moved over
the string. The string should be in the format
inserted by FS FDCONV with argument, and will be
converted to a numeric file date which will be the
value of FS FDCONV. See FS IFCDATE and FS OFCDATE.
<n>:FS FD CONV returns a string containing the
printed representation of the file date <n>, instead
of inserting it in the buffer. Twenex uses ODTIM and
IDTIM, and so is less picky about date formats it will
accept. Also, a second argument to FS FSCONV is used
as the ODTIM format flags.
FS FILE PAD the character used to pad the last word of files
written by TECO. Normally 3 (for ^C).
FS FLUSHED is nonzero if a --MORE-- has been flushed, and
type-out is therefore suppressed. The flag is
positive if the flushage was due to a rubout,
negative otherwise. You can stop generating
type-out when FS FLUSHED is nonzero, or you can
clear it to make type-out start actually appearing
again.
FS FNAM SYNTAX controls TECO's filename readed. If 0, when only
one filename is present, it is used as the fn2
(this is the default). If positive, a lone filename
is used as the fn1. If negative, a lone filename is
used as the fn1 and automatically defaults the fn2
to ">". The default TECO init file
uses this flag to process a DDT command line.
FS GAP LENGTH (read only) the length of the gap.
This is the value of EXTRAC (see "buffer block").
FS GAP LOCATION (read only) the buffer position of the gap.
This is GPT-BEG (see "buffer block").
FS HEIGHT (read only) number of lines on the screen, on display
terminals (including --MORE-- and command lines).
On printing terminals, wil be a very large number.
FS HELP CHAR
contains the character to be used as the HELP character.
Normally, it contains the code for C-_.
However, you may want to bind it to -1 from time to time
to prevent HELP from being recognized
(such as, in the C-Q command).
FS HELP MAC is a macro to be executed if the HELP character is
typed. HELP is Top-H on TV's, ^_H on any terminal.
If FS HELP MAC is zero, the HELP character is
ignored as a ^R command, and returned (as 4110 octal)
by FI and VW.
FS H POSITION (read-only) returns the number of character positions
there would be to the left of the type ball
if the contents of the buffer (or at least
everything after the previous carret) were
printed on a hardcopy terminal with hardware
8 character tabbing and backspace.
FS HSNAME is the user's home directory. The home directory
is a little more permanent than the working directory
(FS MSNAME) and is used for storing things that
permanently belong to the user, such as the RMAIL
file, which do not have their own special directories
the way init files do.
FS I&D CHR if nonzero, tells TECO to try to use the insert and
delete character operations to speed redisplay.
Initialized nonzero if the terminal handles those
operations. Don't set it nonzero otherwise!
FS I&D LINE if nonzero, tells TECO to try to use the insert and
delete line operations to speed redisplay.
Initialized nonzero if the terminal handles those
operations. Don't set it nonzero otherwise!
FS IBASE the input radix for numbers not followed by "."
(initially 8+2)
FS I.BASE the input radix for numbers ended by ".".
Initially 8.
FS IF ACCESS (write-only) sets the access pointer of the
current input file - the argument is the
desired character address in the file.
FS IF CDATE the creation date of the currently open input file.
Arg and value are in numeric file date form -
see FS FD CONVERT.
FS IF DEVICE (read-only) is the device name of the current or
most recent input file, as a numeric SIXBIT word.
FS IF DUMP (ITS only) is the dumped-bit of the currently open input file.
FS IF FDB (Twenex only) is used for reading and writing the file
descriptor block of the current input file.
<n>FS IF FDB returns word <n>, and <m>,<n>FS IF FDB
sets it to <m>.
FS I FILE (read-only) is the name of the current or most
recent input file, as a string. The format is like
that of FS D FILE.
FS IF FN1 (read-only) is the first file name of the current or
most recent input file, as a numeric SIXBIT word.
FS IF FN2 (read-only) is the second file name of the current or
most recent input file, as a numeric SIXBIT word.
FS IF LENGTH (read-only) the length, in characters, of the
currently open input file; or -1, if that length
is unknown (because the file is on a device for
which the fillen system call is unimplemented).
Error if no file is open.
FS IF MTAPE (write-only) executes a .MTAPE call on the input file.
The last argument is the .MTAPE operation.
A preceding argument specifies the count (default is
1). It is not clear that this feature really works.
FS IF REAP is the don't-reap bit of the currently open input file.
FS IF SNAME (read-only) is the SNAME of the current or most
recent input file, as a numeric SIXBIT word.
FS IF VERSION (read-only) is the version number of the open input
file, or -1 if there is none or its FN2 isn't numeric.
FS IMAGE OUT outputs arg as to the terminal as a character in
superimage mode. Returns no value. If the argument
is a string pointer, the contents of the string are
output.
FS IN COUNT is an old name for FS TYI COUNT.
FS INSLEN length of last string inserted into the buffer with
an "I", "G" or "\", or found with a search command
or "FW". FS INSLEN will be negative after a backward
search or "FW" with negative arg. See "FK" and "^F".
FS JNAME (read only) returns the JNAME of the job TECO
is running in, as a numeric SIXBIT word, which
can be converted into text by the F6 command.
Note that the XJNAME is also available, and might
be better for your purpose - see FS XJNAME.
FS LAST PAGE (read only) set to -1 when an input file is opened;
set to 0 as soon as the last char of the file
is read in. Saved by E[ - E]. Updated by
FS IF ACCESS. Thus, FS LAST PAGE; will exit an
iteration if there is no more to be read.
FS LINES (initially 0) determines the number of lines
displayed by standard buffer display, and, for
display terminals, the number of lines to use at all.
0 => a full screen on displays, 2 lines on
printing terminals. <n> not zero => <n> lines.
FS LISPT normally 0, this flag is set nonzero if TECO
is started at 2 + its normal starting address.
This is intended to indicate to TECO programs
that passing of text between TECO and its
superior is desired.
FS LISTEN returns nonzero if there is input available to
be read by "FI". If given an arg, then if no
input is available, the arg is typed out using
FS ECHOOUT.
FS LOAD AV (Twenex only) returns the system load average.
FS MACHINE (read only) returns the name of the machine TECO is
running on, as a numeric SIXBIT word, which can be
turned into text with F6. On ARPANET Twenices, this
returns the local hosts hostname as a string.
FS MODE CHANGE if nonzero means that FS MODE MACRO needs to be run
eventually, to update the contents of ..J. Whenever
TECO is considering updating the mode line, depending
on the value of this flag it may run FS MODE MACRO
first. That macro can recompute ..J to display the
current state of things. FS MODE CHANGE is set to
zero before FS MODE MACRO is called.
The precise condition is: if FS MODE CHANGE is
positive, do run FS MODE MACRO. If FS MODE CHANGE
is negative, its absolute value is compared with twice
the value of FS QP PTR; if the latter is less, do
run FS MODE MACRO. Thus, if FS MODE MACRO sets FS
MODE CHANGE based on the current value of FS QP PTR,
it can arranged to be called again if control returns
to an outer level on the stack. See Q..J and FR.
FS MODE MACRO if nonzero is the macro used to update Q..J when the
mode line is about to be displayed. See FS MODE
CHANGE and Q..J and FR.
FS MODIFIED is the current buffer's modified flag. This flag is
set nonzero whenever the buffer's contents are changed.
It can be read or written by the user at any time.
Each buffer has its own flag, but only the selected buffer's
flag is accessible. The intended use is for deciding
whether a file must be written back to the disk.
See also FS READ ONLY.
FS MP DISPLAY (write only, ITS only) outputs text to the main program
area in display mode (^P is special). The argument may
be a single character or a pointer to a string, whose
entire contents are output.
FS MSNAME is the user's working directory name (set up from
the SNAME that TECO was given when it started up),
as a numeric SIXBIT word, which can be converted into
text by the F6 command.
FS NOOP ALTMODE
if negative, altmode is always a noop as a command.
If 0, altmode is an error as a command.
If >0, always ends execution (as ^_ does).
Initially -1. The old treatment of altmodes
was as if this flag were set to 1.
FS NOQUIT gives the user control of TECO's ^G-quit
mechanism. See "^G".
FS OF ACCESS (write-only) sets the access pointer in the
output file. The argument must be a multiple of
5. If the last output done did not end on a
word boundary, rather than throwing away the
remaining characters, an error occurs.
FS OF CDATE the creation date of the currently open output
file, in numeric file-date form.
FS O FILE returns the filenames of the last output file
explicitly closed, as a string. The format is
like that of FS D FILE. The intended use is for
finding out what version number was actually written.
FS OF LENGTH returns the length in characters of the currently open
output file, or -1 if it cannot be determined.
FS OF MTAPE (write-only) does a .MTAPE call on the output file.
The last argument is the .MTAPE operation.
A preceding argument specifies the count (default is
1). It is not clear that this feature really works.
FS OF VERSION (read-only) is the version number of the last output
file closed, or -1 if that file's FN2 was not numeric.
FS OLD FLUSHED Saves the value of FS FLUSHED when that is set to
zero, on returning to ^R. Thus, a ^R command can
check FS OLD FLUSHED to see whether the previous
command had output which was flushed.
FS OLD MODE is the last ..J value actually displayed in the mode
line. Setting this flag to zero will force redisplay
of the mode line.
FS OSPEED The terminal's ouput line speed in baud, or 0 if the
speed is not known.
FS OS TECO returns the operating system TECO is running on,
0 for ITS, 1 for 20X, 2 for 10X.
FS OUTPUT if nonzero, suppresses output to the EW'd file.
Output commands (P, etc) are errors.
FS PAD CHAR (T(w)enex only) is the character to use for padding
terminal output. Normally it is a Rubout (177). For
some terminals a null (0) is better. Some may set it
to 0 automatically. -1 means use an actual delay
instead of padding characters. This may make some
terminals work better, and may be more efficient of
CPU time; however, it will not work across networks of
any sort.
FS PAGENUM the number of formfeeds read (with non-atsign Y and A
commands) from the input file since it was opened.
FS PJATY this is negative if TECO has detected that the terminal
was temporarily taken away from it. A negative value
here will cause the whole screen to be refreshed at the
next opportunity.
FS PROMPT the ASCII value of the prompt character
(initially 38 for "&"). TECO will prompt
on printing terminals only, whenever it is about
to read from the terminal, and FS PROMPT is not 0.
FS PUSHPT (write-only) pushes its argument on the "ring
buffer of the pointer", but only if the
argument differs from the value already at the
top of the ring buffer. See the ^V command.
Note that TECO's top level loop does
Q..IFS PUSHPT each time it is about to read in
a command string.
<n>FS QP HOME returns a string which says where the q-register
pdl slot <n> was pushed from. <n> can be a
nonnegative offset from the bottom of the stack or
a negetive offset from the top. The string will
contain the name of the q-register of FS flag that
was pushed, as, for example, "QA", "Q.^RX", "QFoo",
"FS DFILE", or "*" (for a [(...) ). "*" isn't really
a q-register name, but what would be any better?
<n>:FS QP HOME returns the address of the q-register which
q-register pdl slot <n> was pushed from (for a variable,
returns the name of the variable). Such numbers
will be equal for two slots pushed from the same place
in the same TECO. They are also used with F^G.
<n>@FS QP HOME
turns a q-register address returned by :FS QP HOME
into a string such as plain FS QP HOME would return.
@FS QP HOME may be useful in for decoding the local
q-register home numbers used with the F^G command.
FS QP PTR the q-register pdl pointer (0 if nothing has been
pushed, 1 if one q-reg has been pushed, etc.)
<n> FS QP PTR sets the pointer to <n> if <n> > 0;
adds <n> to it if <n> is negative. It is illegal
to increase the pointer value with this command.
FS QP SLOT <n> FS QP SLOT reads q-reg-pdl slot <n>.
<m>,<n>FS QPSLOT sets it to <m>.
The first slot is numbered 0.
If <n> is negative, it is treated as FS QPPTR+<n>.
Thus, -1FS QP SLOT is the last slot pushed.
FS QP UNWIND (write only!) like FS QP PTR but pops
slots back into the q-reg's they were pushed from
instead of simply decrementing the pdl poinetr.
This unwinding is automatically done when an error
is caught by an errset, and at the end of each
command string, and by ^\ and FS ^REXIT.
If Q..N is popped by this command, it is macroed
first (see ..N).
If <n> is negative, <n>FS QP UNWIND pops -<n> slots.
FS QUIT ^G-quit works by setting this flag negative.
Whenever quitting is possible (see FS NOQUIT)
and FS QUIT is negative, quitting will occur
(and FS QUIT will be zeroed automatically).
When TECO's quitting is inhibited, the user can
test this flag explicitly to do his own special
quitting.
<n>FS Q VECTOR (a pseudoflag) returns a newly cons'ed up q-register
vector, <n> characters long. <n> should normally
be a multiple of 5. The contents are initialized
to zeros, and the pointer is at the beginning
of the qvector. A q-vector is really a buffer, each
word of which is marked by the garbage collector.
See the section on data types.
FS RANDOM reads or sets the ^Z command random number
generator's seed.
FS READ ONLY if nonzero makes it an error to modify the buffer.
This flag is actually per-buffer, so when you set it,
you set it only for the currently selected buffer.
FS REAL ADDRESS
returns the value of BEG, the character address
of the beginning of the current buffer. Useful
for communicating with other programs that need
to be given addresses of data in their commands.
Also useful for executing the buffer as PDP10
code (do FS REALAD/5U0 M0; the code should be
position-independent, expect its address in
accumulator 5, and start with SKIP (skip never)
instruction. Its argument will be in AC 3.).
FS REFRESH if nonzero, is macroed each time TECO really
clears the whole screen. It is given no args
and its values are ignored. The screen will
already have been cleared.
When only part of the screen is in use (because FS
LINES and FS TOP LINE call for that), the only time
that TECO will clear the whole screen is when it is
continued after having been stopped, the primary use
of this hook is to put back on the screen whatever is
supposed to be in the part of the screen not being
actively used for display.
Functions which remove part of the screen from
active use can sometimes be entered recursively, each
one removing a few more lines from use. Each of them
might supply an FS REFRESH to refresh those lines.
What ought to happen is that all the FS REFRESHes are
executed, in the order they were set up. To make this
happen, any function which sets up an FS REFRESH
should save the previous contents elsewhere, and the
new FS REFRESH should call the old one first thing.
FS REREAD (usually -1) if nonnegative, FS REREAD is the
9-bit TV code for a character to be re-read.
Putting 65 into FS REREAD will cause the next
"FI" command to return 65 (and set FS REREAD
back to -1).
FS RGETTY 0 if printing console,
otherwise equal to the tctyp word of the
terminal. However, it is better to decode the
FS %TOCID, etc., flags than to decode FS RGETTY
when trying to determine what kind of display
the terminal is, and what functions it can perform.
On Twenex it is actually allowed to set this variable
in case the system is mistaken about your terminal
type. What it must be set to is the TECO internal
type code for the terminal you are using; and not all
types are assembled in on any particular Twenex site.
FS RUB CRLF if nonzero causes the initial definitions of
^D, rubout and control-rubout to delete both
characters of a CRLF at one blow, as if it were
a single character.
FS RUB MACRO if nonzero is a macro to be called to perform the
^R commands Rubout and C-D when they have explicit
numeric arguments. The normal definitions of the
two characters call this macro in that case.
FS RUNTIME (read-only) TECO's runtime in milliseconds.
FS SAIL if nonzero, the terminal is assumed to be able
to print non-formatting control chars as 1-space
graphics. TECO outputs them as they
are instead of outputting an ^ and a non-ctl char.
Terminal initialization zeros this flag if the
terminal's TOSA1 bit is 0
(this bit is set by :TCTYP SAIL).
FS S ERROR if 0, as it is initally, a failing serach within an
iteration or a ^P-sort key is not an error - it
simply fails to move the pointer. If not 0, such
searches cause sfl errors like all other searches.
FS SHOW MODE if nonzero, causes FR to type out the mode line
(Q..J) on printing terminals, if it has changed
since last printed. Has no effect on displays.
FS S HPOS (read only) is the horizontal position of point,
taking control characters, CRs, etc. to appear the way
they are currently being displayed, but assuming an
infinitely wide line.
FS S STRING is the default search string (which S will use),
as a string pointer. Do G(F S STRING) to insert
it in the buffer. This flag is most useful for
pushing and popping.
FS STEP MACRO (normally 0) if nonzero and numeric, TECO displays
the buffer and waits at the beginning of every line
of the program. See ^M for details.
If it is a string, it is executed at the beginning
of every line in the program.
Exception: if a macro begins with a "W", stepping
is inhibited at the beginning of that macro.
The macro can inhibit stepping throughout itself
by starting with "W 0F[STEP MAC".
Exception: stepping is also done whenever a
successful conditional begins.
FS STEP DEPTH restricts the macro call stack levels at which
stepping is done. If FS STEP DEPTH is -1, as it is
initially, stepping goes on at all stack levels.
Otherwise, the value of FS STEP DEPTH is the largest
macro call depth (FS BACK DEPTH value) for which
stepping can take place.
FS SUPERIOR if nonzero is the macro to be called when TECO's
superior makes a request to insert text into TECO.
See "How Superiors Can Put Text into TECO" below.
FS S VALUE the value stored by the last search command
(0 if search failed; else negative, and minus
the number of the search alternative which was
actually found).
FS TOP LINE is, on display terminals, the number of the first
line on the screen that TECO should use.
Normally 0, so TECO starts output at the top of
the screen.
FS TRACE nonzero iff TECO is in trace mode. See "?".
1F[ TRACE is a good way to start tracing temporarily.
FS TRUNCATE says what to do with long lines of type-out.
Negative => truncate them.
Positive or zero => continue them to the next line.
Entering ^R sets this flag to 0.
FS TTMODE (initially 0) non-zero tells TECO that normal
buffer display should display on printing terminals.
(if there is a user buffer display macro, this
flag has no effect unless the macro checks it)
FS TT PAGE MODE
(Twenex only) if non-zero, prevents TECO from leaving
page mode, so that ^Q and ^S are still used for flow-control.
Note that this means they are not available as commands.
FS TTY INIT (no argument or value) causes TECO to reexamine
the system's terminal description and reset various
flags, and the cursor in ..A, appropriately.
Then, FS TTY MACRO is executed if nonzero. It can be
used to digest the tty characteristics and set flags
accordingly. FS TTY INIT is run automatically when
TECO is started or restarted.
In detail, ..A is set to "-!-" on printing terminals,
and to "/\" on displays (but "^A^B" on imlacs).
FS RGETTY is set up to be 0 on a printing terminal,
nonzero otherwise. FS VERBOSE is set equal to
FS RGETTY. FS TTYOPT is read in from the system.
FS ^H PRINT is zeroed unless the terminal
can backspace and overprint; FS ^M PRINT is zeroed
unless the terminal can overprint.
FS SAIL is set nonzero if the %TOSA1 bit is set in
TTYOPT (this is the bit ":TCTYP SAIL" sets).
FS LID is set nonzero if the %TOLID bit is set in
TTYOPT. %TOLID says that the terminal can insert and
delete lines.
FS WIDTH and FS HEIGHT are read in from the system.
FS ECHOLINES is set to 0 on printing terminals;
1/6 of the screen size on displays.
FS D WAIT is set to -1 if FS OSPEED is positive and
600 or less; to zero, otherwise.
FS TTY MACRO is a macro called by FS TTY INIT to give the user a
chance to alter TECO flag settings based on the
newly-gobbled terminal characteristics.
If you don't like the way TECO initializes certain FS
flags (namely FS ECHOLINES, FS TRUNCATE, FS
VERBOSE, FS WIDTH, FS ^HPRINT, FS ^MPRINT, and FS
SAIL) in FS TTY INIT, this macro can change them.
Pure strings should NOT be used for this; when a saved
EMACS environment is restored, FS TTY MACRO$ is
processed before even the standard libraries are
loaded in. So you must create the string with :I, X
or :G. You can make an impure copy of a pure string
in Q0 with :I0 0.
FS TTYOPT (read-only) the TTYOPT word for the terminal.
However, if you think you want to use this flag, see
FS %TOCID, etc., first.
FS TTYSMT (read-only) the TTYSMT word for the terminal.
FS TYI BEG is the value which FS TYI COUNT had on the last time
through the main ^R command loop. In other words, it
is the number of terminal input characters so far, not
including the last or current ^R command. Commands to
set the numeric argument do not count as real commands
in this regard; they are grouped with the commands
for which they set the argument.
When ^R is reading the first character of a command,
FS TYI COUNT has been incremented already, so it
equals FS TYI BEG+1.
FS TYI COUNT is the number of characters read from the terminal so
far.
FS TYI SINK if nonzero holds a macro to be called every time a
character is read from the terminal (not from FS
REREAD or from FS TYI SOURCE). The character read,
in the 9-bit code, is passed as a numeric argument to
the macro. The macro should return a single value,
for the sake of ^R display updating. FS TYI COUNT
and FS TYI BEG may be of use in the macro.
FS TYI SOURCE if nonzero holds a macro to be called to obtain
"terminal input". This is instead of reading from the
keyboard. The macro should put the input character
it wishes to provide into FS REREAD and then return.
The macro should return a single value, for the sake
of ^R display updating, but this value is not used in
any other way. That FS TYI SOURCE is nonzero is
taken to imply that input is available, so display
updating is suppressed. To cause displaying to be
done, you must bind FS TYI SOURCE to zero and then
request it. FS TYI SOURCE is set to zero by anything
that discards keyboard input (errors, quits, etc).
FS TYO HASH <vpos>FS TYO HASH returns the hash code of the screen
line at position <vpos>. <n>,<vpos>FS TYO HASH sets
the hash code of that screen line to <n>. This is
useful primarily for -1,<vpos>FS TYO HASH which will
force that screen line to be redisplayed.
FS TYO HPOS (read-only) while typeout is in progress (FS TYPEOUT
nonnegative), holds the current typeout horizontal
position, in which the next typed character will appear.
FS TYPEOUT is -1 if typeout has not been happening recently,
so typeout starting now would appear at the top of
the window. FS TYPEOUT is not -1 when typeout was
the last thing to happen and any more typeout will
appear after the previous typeout. :FT types at
the top of the window by putting -1 in FS TYPEOUT
before typing.
FS U HSNAME is used to determine a user's hsname.
<user> FS U HSNAME (where <user> is sixbit) returns
<user>'s hsname in sixbit. <its>,<user> FS U HSNAME
returns his hsname on machine <its> (sixbit).
FS UINDEX (read only) The user index of the TECO job.
FS U MAIL FILE is used to determine the filename (including the
machine) of a user's mail file. <user>FS U MAIL sets
the default filename to the name of <user>'s mail file
(where <user> is in sixbit). <its>,<user>FS U MAIL
sets them to the name of his mail file on machine
<its> instead of his normal mail-receiving machine.
FS UNAME (read only) returns the UNAME of the job TECO is
running in, as a numeric SIXBIT word, which can be
converted into text by the F6 command. See also
FS XUNAME and FS MSNAME, one of which might be
better for your purpose.
FS UPTIME (read only) returns time system has been up, in 30'ths,
(milliseconds on Twenex).
FS UREAD (read-only) -1 iff an input file is open, else 0.
Once an input file is opened, it remains open until
"EC", "@Y", "@A", "EE" or "EX" is done.
FS UWRITE (read-only) -1 if an output file is open, else 0.
FS VAR MACRO if nonzero enables the feature whereby setting a named
variable can run an arbitrary macro to make changes in
other data structures. These data structures will
appear automatically to reflect the value of the
variable.
To use this feature, allocate three words per variable
in the symbol table in Q..Q. The macro to call is the
contents of the third word, but only if it is a string
which starts with a "!". If that is the case, it will
be called with the new value of the variable as its
argument.
FS V B is the distance between the real beginning of the
buffer and the virtual beginning. See FS BOUNDARIES,
but unlike that flag, FS V B can be pushed and popped.
FS VERBOSE if not 0, TECO will print the long error message
of its own accord when an error occurs.
Otherwise it will print only the 3-char code
and the long message must be requested by typing
^X. Initially 0 except on displays.
FS VERSION (read-only) the current TECO version number
FS V Z is the distance between the virtual end of the buffer
and the real end - the number of characters past the
virtual end. See FS BOUNDARIES for more info, but
note that FS V Z can be pushed and popped.
FS WIDTH width of terminal's screen or paper, in characters.
FS WINDOW the number of the first character in the
current display window, relative to the virtual
beginning of the buffer (that is, FS WINDOW+B
is the number of that charcter).
FS WINDOW+BJ (FS HEIGHT-(FS ECHOLINES)/2)L
will put the pointer in the middle of the window
(usually). Setting FS WINDOW will make TECO try
to use the window specified. However, if the
constraints of FS %TOP and FS %BOTTOM are not
met, TECO will choose another window rather than
use the specified one.
FS WORD gets or sets words in the current buffer. This
flag makes it possible for TECO programs to
edit binary data bases.
<n>FS WORD returns the contents of the word
containing character <n>; <val>,<n>FS WORD
sets that same word.
When handling binary data, it is unwise to
insert or delete characters other than in units
of five, on word boundaries. The way to delete
a word is to delete its five characters; insert
a word with 5,0I (it will contain either 0 or 1).
To read in a file of binary data, FY should be
used, since Y might pay special attention to the
characters in the file. Copying out of another
buffer with G works, provided the transfer starts
and ends on word boundaries (blt is used).
For writing out binary data, use "HP" rather than
"PW" - "PW" may add a "^L". "EF" is OK for closing the
file - it will add no padding if it is done at a
word boundary.
FS XJNAME (read only) returns the XJNAME of the job TECO is
running in, as a numeric SIXBIT word, which can be
converted into text by the F6 command. The XJNAME is
"what the JNAME was supposed to be", so if you want
your init file to do different things according
to how TECO was invoked, you should use the XJNAME
rather than the JNAME.
FS X PROMPT On printing terminals, all commands that type out
first print and zero FS X PROMPT if nonzero (using
FS ECHO OUT). Do not try to use it on displays.
FS XUNAME (read only) returns the XUNAME of the job TECO
is running in, as a numeric SIXBIT word, which
can be converted into text by the F6 command.
The XUNAME is "who the user really is".
For example, it is what TECO and other programs
use to decide whose init file to use.
FS Y DISABLE controls treatment of Y command.
0 => Y is legal.
1 => Y is illegal (gives "DCD" error).
-1 => Y is always treated as @Y.
FS Z (read only) the number of characters in the buffer.
Will differ from value of Z command when virtual
buffer boundaries don't include the whole buffer.
This is Z-BEG (see "buffer block").
note: in the names of the following flags,
"^" represents uparrow, not a control character.
Control characters cannot be part of FS flag names.
FS ^H PRINT controls how ^H is typed out.
Negative => actually backspace (and overprint),
otherwise type the ^H as uparrow-H.
FS TTYINIT and G cause this flag to be zeroed
if the terminal cannot handle overprinting.
FS ^I DISABLE controls the treatment of the tab character
as a TECO command.
0 => ^I is an insert command (see Tab for details).
1 => ^I is illegal (gives "DCD" error).
-1 => ^I is a no-op.
FS ^L INSERT (initially 0) if 0, formfeeds in files that terminate
Y commands' reading, are thrown away, and the P and PW
commands output a formfeed after the buffer.
If FS ^LINSERT is nonzero, formfeeds read from files
always go in the buffer, and P and PW never output
anything except what is in the buffer.
Either way, a Y and a P will write out what it
reads in.
FS ^M PRINT says when a stray CR or LF should be typed out
as one, as opposed to being printed as "^M" or "^J".
Possible values and initialization like FS ^H PRINT
FS ^P CASE if nonzero, ^P sort ignores case (lowercase
letters sort like the corresponding uppercase).
FS ^R ARG is the explicit numeric argument for the next ^R
mode command, or 0 (not 1!) if there was none.
FS ^R ARGP contains two bits describing this ^R-command's
argument:
bit 1.1 (1) is set if any argument was specified
(either numerically or with ^U).
bit 1.2 (2) is set if a numeric argument was
specified. If this bit is 0, the contents of
FS ^R ARG are ignored, and 1 is used instead.
bit 1.3 (4) is set if the argument, as specified by
the other bits, should finally be negated.
FS ^R CCOL the comment column, for ^R's comment mode.
FS ^R CMACRO <n>FS ^RCMAC gets the ^R-mode definition of
the character whose ASCII code is <n>.
<m>,<n>FS ^RCMAC sets it to <m>.
<n> should be an ASCII code; it will be converted
to 9-bit TV code which is what is actually used
to index the ^R-mode dispatch table.
If you wish to supply a 9-bit code yourself, use
"@FS ^RCMAC" which skips the conversion.
Also, these definitions may now be referred to
as q-regs in all the q-reg commands - see "Q".
The definition is either a built-in command or
a user macro. In the former case, the
definition is a positive number of internal
significance only. However, built-in
definitions may be copied from one character
to another using FS ^RCMAC. For a character to
be a user macro, its definition must be one of
the funny negative numbers which are really
string pointers. They can be obtained from
strings by applying the "Q" command to a q-reg
that contains text. For example, to make the
definition of the character " " be the string
which is at the moment in q-reg A, do
"QA,^^ FS ^RCMACW". "QAU^R " is equivalent.
To copy the definition of
"A" into the definition of rubout, do
"^^AFS ^RCMAC,127FS ^RCMACW". This will make
rubout self inserting (unless "A" had been
redefined previously).
FS ^R DISPLAY if nonzero is macroed every time ^R is about to do
nontrivial redisplay (anything except just moving
the cursor).
If the evaluation alters the needed redisplay
(either by returning 0 or 2 values to ^R, or by
doing some of the redisplay with ^V) then ^R will
take note. If a FS ^R DISPLAY returns no values,
it will force a full redisplay, thus effectively
disabling ^R's short-cuts, so beware.
If FS REFRESH is nonzero, then it will be called
in addition to FS ^R DISPLAY, at those times when
the whole screen is being cleared.
FS ^R EXIT (write-only) exits from the innermost ^R invocation.
Pops q-regs pushed within that ^R level, and ends
iterations started within it.
FS ^R ECHO 1 => characters read in by ^R should not be echoed.
0 (the default) => they should be echoed only on
printing terminals.
-1 => they should be echoed on all terminals.
Note that this "echoing" is explicit typeout by TECO.
System echoing is always off in ^R mode, currently.
Also, rubout is not echoed on printing terminals.
However, FS ^R RUBOUT on a printing terminal when
FS ^R ECHO is <= 0, types out the char being
deleted.
FS ^R EC SD is used to allow system echoing to echo the Space
character when some sort of auto-fill feature is in
use and Space does not have the definition of a normal
self-inserting character. This flag should be set to
the definition which Space has when it does
auto-filling. When Space has this definition, it will
be considered safe to let the system echo Spaces just
as if they were ordinary self-inserting characters;
however, to prevent auto-fill from being lost, system
echoing will be allowed only as far as the column
which is the value of FS ADLINE, which should be set
no greater than the column at which auto-fill starts
to do something nontrivial. The definition of Space
will not actually be executed when the space is echoed
by the system, but for an auto-fill which isn't going
to break the line this should make no difference.
FS ^R ENTER is macroed (if nonzero) whenever ^R is entered
at any level of recursion.
FS ^R EXPT is the ^U-count for the next ^R-mode command.
FS ^R H MIN (read only) is the hpos of the first change on the
screen needing redisplay. It will be a large positive
number if no redisplay is required. If FS WINDOW is
negative then the value of this flag doesn't matter.
FS ^R HPOS the current horizontal position of the cursor
in ^R mode. Not updated when the pointer moves,
unless ^R gets control back or @V is done.
FS ^R INDIRECT given a 9-bit character, traces ^R alias-definitions
to find the character it is equivalent to. If given
a character that isn't an alias, returns the same one.
Thus, 311. FS ^R IND returns 11.
FS ^R INHIBIT when nonzero prevents ^R from updating the display.
If FS ^R INHIBIT is zeroed again, all the pending
updating will be done at the next opportunity.
FS ^R INIT <ch>FS ^R INIT returns the initial definition of
the character whose ASCII code is <ch>; in other
words, <ch>FS ^R INIT always returns what
<ch>FS ^R CMACRO initially returns.
The atsign modifier works for FS ^R INIT just
as it does for FS ^R CMACRO; it says that the
arg is a 9-bit code rather than ASCII.
FS ^R INSERT the internal ^R-mode insert routine's user interface.
It takes one argument - the ASCII code for the
character to be inserted. This command itself take
care of notifying ^R of the change that is made, so
when returning to ^R this change should not be
mentioned in the returned values (so if this is the
only change made, return 1 value).
This command is very sensitive; if the buffer or
even "." has changed since the last time ^R was
in progress or an @V was done, it may not work.
Its intended use is in macros which, after thinking,
decide that they wish only to insert 1 or 2
characters (such as a space-macro which might
continue the line but usually inserts a space).
FS ^R LAST holds the most recent character read by any ^R
invocation (quite likely the one being processed
right now). Commands that wish to set up arguments
for following commands should zero FS ^R LAST,
which tells ^R not to flush the argument when
the command is finished.
FS ^R LEAVE is macroed (if not zero) whenever ^R returns
normally (including FS ^R EXIT but not throws
that go out past the ^R).
FS ^R MARK holds the mark set by ^T in ^R mode, or -1 if
there is no mark.
FS ^R MAX holds the maximum number of characters of insertion
or deletion that will be printed out by ^R on
a printing terminal. Larger changes will cause ^R
to echo the command instead of displaying its effect.
The default value is 50 .
FS ^R MCNT the counter used by ^R to decide when to call
the secretary macro. It starts at FS ^R MDLY and
counts down.
FS ^R MDLY sets the number of characters that should be read
by ^R mode before it invokes the secretary macro
kept in q-register ..F . Characters read by
user macros called from ^R are not counted.
FS ^R MODE (read-only) non-zero while in ^R-mode.
FS ^R MORE if positive, --MORE-- is used for ^R-mode display
instead of the usual --TOP--, --BOT-- and --nn%--.
This is useful in command environments where Space
means "show the next screenfull".
If negative, then neither --MORE-- nor --TOP-- is
displayed. This may be desirable on slow terminals,
and also allows ..J to make use of the full width of
the mode line.
FS ^R NORMAL all "self-inserting" characters in ^R mode are
really initially defined to go indirect through
this word, if it is nonzero. If it is zero, as
it is initially, the default definition is used
for such characters.
FS ^R PAREN holds a function to be executed whenever a
self-inserting character is inserted whose Lisp syntax
is ")". The idea is that this function will point out
the location of the matching open parenthesis. If FS
^R PAREN is zero, the feature is turned off.
FS ^R PREVIOUS holds the previous (second most recent) command
read by ^R's command loop, not counting argument
setting commands.
FS ^R REPLACE if nonzero puts ^R in "replace mode", in which
normal characters replace a character instead of
simply inserting themselves. Thus, the character
A would do DIA instead of just IA. There are
exceptions, though; a ^H, ^J, ^L or ^M will not
be deleted, and a tab will be deleted only if
it is taking up just one space. Also, characters
with the meta bit set will still insert.
Replace mode actually affects only the default
definition of "normal" characters. Characters which
have been redefined are not affected, and if
FS ^R NORMAL is nonzero no characters are affected
(unless the user's definitions check this flag).
Making FS ^R REPLACE positive has the additional
effect of forcing all meta-non-control characters
to be come normal, suppressing their definitions.
FS ^R RUBOUT the internal ^R rubout routine's user interface.
Takes 1 arg - the number of characters to rub out.
This command is very sensitive and may fail to work
if the buffer or "." has been changed since the
last time ^R was in control, or an @V, FM,
FS ^R RUB or FS ^R INSERT was done. Its intended
use is for macros which, after thinking, decide
to do nothing but rub out one character and
return; it gives extra efficiency but only when
rubbing out at the end of the line.
FS ^R SCAN if nonzero causes ^R commands,
when using a printing terminal, to try to imitate
a printing terminal line editor by printing the
characters they insert/delete/move over.
FS ^R ECHO should be 1, to avoid double-echo.
FS ^R SUPPRESS (initially -1) nonnegative => builtin ^R-mode
commands are suppressed, except for rubout,
and user-defined commands are suppressed unless
their definitions begin with "W". Suppressed
command characters become self-inserting. The char
whose 9-bit value is in FS ^R SUPPRESS is the
unquoting char. It reenables suppressed commands
temporarily by setting FS ^R UNSUPPR to -1. If
FS ^RSUPPRESS is > 511, there is no unquote char.
FS ^R THROW returns control to the innermost invocation of
^R. This is different from FS ^R EXIT, which
returns control FROM that invocation.
FS ^R UNSUPP (initially 0) actually, builtin commands are
suppressed only if this flag and FS ^RSUPRESS
are nonnegative. However, this flag is zeroed
after each command except ^U and ^V. Thus,
setting this flag to -1 allows one builtin comand.
FS ^R V MIN (read only) is the vpos of the first change on the
screen needing redisplay. It will be a large positive
number if no redisplay is required. If FS WINDOW is
negative then the value of this flag doesn't matter.
FS ^R VPOS the ^R-mode cursor's vertical position.
FS _ DISABLE controls treatment of the "_" command.
If 0 (the default), "_" is "search-and-yank"
as it originally was.
If 1, "_" is illegal (gives "disabled command" error).
If -1, "_" is treated like "-"
(good on memowrecks).
FT types its string argument.
:FT similar, but always goes to top of screen first (actually,
to the line specified by FS TOP LINE).
@FT similar to FT, but types its argument in the echo area
rather than the display area. Characters are typed normally,
in ITS ASCII mode, rather than as they would echo, so to do
a CRLF you need a CR and a LF.
@:FT like @FT, but types the argument only if no input is
available (FS LISTEN would return 0). If input is
available, the argument is skipped over and ignored.
FU a list manipulating command whose main use
is in <arg>FUL, which moves up <arg> levels of parentheses.
<arg>FU where <arg> is positive returns a pair of args for
the next command, specifying the range of the buffer from .
Moving rightward to the first place <arg> levels up.
If <arg> is negative, it moves left -<arg> levels up.
FV displays its string argument.
:FV types its string argument, then clears whatever is
left of the screen.
FW similar to FL but hacks words instead.
A word is defined as a sequence of non-delimiters.
Initially, the non-delimiters are just the squoze
characters but the user can change that - see q-reg ..D.
This command returns a pair of args for the next one.
Also, FW sets FS INSLEN equal to the length of the
last word moved over.
Main uses: FWL moves right one word,
-FWL moves left one, FWK deletes one word to the right,
FWFXA deletes and puts in q-reg A,
FWFC converts one word to lower case.
:FW similar to FW but stops before crossing the word instead
of after. Thus, :1FWL moves up to before the next
non-delimiter. :2FWL is the same as 2FWL-FWL.
:FW sets FS INSLEN to the length of the last inter-word
gap crossed.
@FW like FW, but finds LISP atoms rather than words.
Understands slashes and vertical bars but not comments.
FX like X and K combined. "3FXA" = "3XA 3K".
The atsign flag causes appending to the q-reg, as for X.
FY insert all that remains of the current open input file
before point. Error if no file is open. The input data are
unaltered; no attempt is made to remove padding or ^L's.
If the transfer is on a word boundary in the file and in
the buffer, word operations will be used, so this command
is suitable for use with binary data.
The input file is not closed - use EC for that.
<n>FY like FY, but inserts at most <n> characters, or until EOF,
whichever comes first. Note that <n> characters of
space are always needed, even if the file is not really that
long; thus, 1000000FY to read in the whole file will
not work. The input file is not closed.
FZ (T(w)enex only) manipulates inferior forks.
FZ resumes the inferior exec fork, creating it if there is none.
There is at most one "exec fork" since FZ will not create one
if one already exists.
0FZ<filename>
creates and starts a new exec fork loading in the specified
file. This new exec fork replaces any existing one to become
"the" exec fork, which following FZ's with no argument will
resume. There are no defaults for the filename.
FZ<filename>
creates and starts a non-exec fork by loading the specified
file (no defaults!). A pre-comma numeric arg specifies the
offset in the entry vector for starting the program. The @
modifier if present tells TECO to assume that the inferior
will not touch the screen. After the fork returns, the FZ command
returns a positive number which is the TECO index of the fork.
This index can be used to resume or kill the fork:
<i>FZ resumes the fork of index <i>, and waits for it to return.
-<i>FZ kills the fork of index <i>. Indices are always positive.
F[<flag>
pushes the value of FS<flag> on the q-reg pdl,
so that it will be restored on unwinding.
<arg>F[<flag>
pushes the flag and sets it to <arg>
<ch>F[ ^R CMACRO
pushes the definition of character number <ch>.
<arg>,<ch>F[ ^R CMACRO
pushes the definition of character number <ch> and sets it.
F_ this command has the same meaning that _ normally has;
namely, search for a string arg and keep yanking till
end of file. However, this command works regardless of
the setting of FS _DISABLE
F]<flag>
pops from the q-reg pdl into FS <flag>.
<ch>F] ^R CMACRO
pops from the q-reg pdl into the definition of character
number <ch>, and returns the old definition.
F~ compares strings, ignoring case difference. It is just
like F= except that both strings are converted to upper
case as they are compared.
G<q> insert in buffer to left of pointer the text in q-reg <q>.
If q-reg specified contains # rather than text, decimal
representation thereof will be inserted. If the q-reg
contains a buffer the gap in the buffer may have to be
moved before the G can be done.
FS INSLEN is set to the length of the inserted text.
<m>,<n>G<q>
insert only a part of the text in the q-reg; specifically,
the range from <m> to <n>-1 inclusive. This feature works
only for q-regs containing text; if a q-reg holds a number
the whole q-reg will be inserted despite the args.
:G<q> returns a copy of the string in q-register <q>.
<n>:G<q>
returns as a number the character at position <n> in the
string in <q>. It is an error if <n> is negative or >= the
length of the string.
<m>,<n>:G<q>
makes a substring of the string in <q>, taking the
characters starting form position <m> and stopping before
character <n>. This substring is returned as a value.
FS INSLEN is set to the length of the substring.
H equivalent to B,Z; i.e., specifies whole buffer
(or all within the virtual boundaries if they're in use)
to commands taking two args for character positions such as
K, T, or V.
I if no arg, insert following chars
up to altmode in buffer to right of
pointer. If preceded by an atsign ("@")
following char is delimiter to end
text string instead of altmode,
e.g., @I/text/.
The length of the inserted string is kept in FS INSLEN
(see the "FK" and "^F" commands).
:I<q> takes a q-register name immediately after
the I and inserts into that q-reg,
replacing the previous contents.
Atsign works as with the
normal I command, with the delimiter
following the q-reg name.
FS INSLEN is not set by :I.
Self-inserting chars will not take
the colon modifier.
<n>I inserts the character with ASCII code <n>.
<n>:I<q>
puts the character in a string in q-reg <q>.
<m>,<n>I
inserts <m> copies of the character with ASCII code <n>.
<m>,<n>:I<q>
puts <m> copies of the character in a string in q-reg <q>.
J position pointer after argth char
in buffer. If no arg, arg=B (usually 0).
:J is to J as :S is to S.
K if no arg or one arg, kill chars
from pointer to argth line feed
following. (no arg, arg=1; negative
arg, back up over 1-arg line feeds,
space over last line feed found, and
kill from there to pointer. A colon
after the arg will move back over
carriage return+linefeed before deleting.
If no carriage return exists,
TECO will only move back one character.
There is an implicit line-feed at the end of
the buffer. (note: this is the action of colon
for all commands which take
one or two args like K.)
<m>,<n>K
kills characters <m> through <n>-1.
The pointer is moved to <m>.
<n>@K is like <n>K, but only LF's preceded by CR's are
recognized.
L:
<arg>L move to beginning of <arg>th line after
pointer (0L is beginning of current
line.). Colon acts as in the K command.
Note that :L moves to end of current line
0:L moves to end of previous line
and -:L moves to end of line before
previous line
<m>,<n>L is the same as <m>+<n>-.J
<arg>@L
is like <arg> L but only CRLFs are recognized, not stray LF's.
M<q> calls the function in q-reg <q>. If <q> contains
a string or buffer, its contents are "macroed" -
that is, treated as TECO commands.
If <q> contains a number, that number should be the
initial definition of some ^R-mode character;
that "built-in" function will be called.
Built-in finctions take 1 arg; user macros,
0, 1 or 2, which they may access using "^X" and "^Y"
(or, more winningly, with the F^X and F^Y
commands). The macro may read string arguments using
the ^]^X construction; such arguments should be
supplied after the M command.
Note that if you macro a buffer, you may screw yourself
if while that buffer is executing you either
modify its contents or throw away all pointers to it.
If the q-register specified in the M command is a
^R-mode character definition (as in M.^RX), the code
for that character is put in Q..0 in case the definition
looks at it there.
@M is a variant of M that fools the called macro into thinking
that it was called directly from ^R mode. One effect is that
the default postcomma numeric argument is 1, not 0. To be
precise, if a macro is called with @M and no arguments, then
inside that macro F^X will still say that there are no
arguments, but if ^Y is used anyway its value will be 0, not 1.
Another effect is that if the called macro uses the F^K
command to read a string argument, the argument will be read
from the terminal. If a macro called with @M does a :M, the @
flag will be passed along to the macro called by the :M;
however, this will not affect the argument passed by the :M,
which will be determined solely by the code in the caller
(including whether the caller explicitly says @).
:M is a tail-recursive form of macro call; it is similar to a M
followed by a ^\, for some purposes. However, with :M the
caller is really no longer present on the macro call stack.
If the called macro reads a string argument, it will come not
out of the caller, but out of the caller's caller.
N does search (see S) but if end of
buffer is reached does P and
continues search.
O<tag> sends command execution to char after
the occurrence of <tag> as a label ("!<tag>!")
( OX goes to !X!). Case is not significant in tags,
so OFOO and Ofoo will both find both !FOO! and !foo!.
Label must be on same iteration level as O command,
i.e., no unmatched < or > between O and !.
The label must also be within the same macro as
the O; in other words, non-local gotos are not
implemented.
If the tag is not found, an "UGT" error occurs at
the end of the O command. For convenience's sake,
:O is just like O but simply returns if the tag
is not found.
The @ modifier allows the tag to be abbreviated.
OFOO will not find !FOOBAR!, but @OFOO will find it.
This is for the sake of those using O to do command
dispatching.
TECO has a cache containing the locations of
several recent O commands and where they jumped to.
If an O command is in that table, searching is
unnecessary. This increases efficiency. However, if
there is a ^] call in the arg to O, it might be
intended to jump to different places each time, so
TECO refuses to cache such jumps to force itself to
search each time. Also, jumps in buffers and in
top level command strings cnnot be cached, since the
data in the buffer (including the argument of the O
command) might change at any time; if TECO then did
not read the argument and search, it might jump to the
wrong place.
P output contents of buffer to device
open for writing, followed by form feed (^L)
if FS ^LINSERT is 0; clear buffer and read
into buffer from file open for
reading until next form feed or end
of file. Takes one arg, meaning
do it arg times, or two args, meaning
output specified portion of buffer
(args as in K command) without
following form feed, and without
clearing buffer or doing input.
Note: if next command char
is W, this is not P command but
PW which outputs like P but does not
clear buffer or do input. Takes
arg, meaning do it arg times.
Q<q> returns the value in q-reg <q>, as a number. If <q>
is holding a number, that number is the value.
If <q> "holds text", then it really contains a pointer
to a string or buffer, and Q<q> wil return the pointer,
which if put in another q-reg (using "U") that q-reg
will "hold the same text" as <q>.
A q-reg name is either an alphanumeric char preceded
by 0, 1 or 2 periods,
a "variable name" of the form <name>,
a subscripting expression such as :Q(<idx>),
a * (for certain commands),
an expression in parentheses (for certain commands),
or up to 3 periods followed by a "^R" or "^^" and any
ASCII character.
Periods plus alphanumeric character q-reg names refer
to TECO's q-registers, which are what serve as variables
for TECO programs. Each distinct such name names a
distinct variable. Names with two periods are
reserved for special system meanings; those that
are now assigned are documented starting at "..A".
While names like "A" or ".8" are fine for local variables
in programs, for global parameters mnemonic names are
necessary. Variables with long names are accessible through
the <name> construct. Variable names may be abbreviated,
and extra spaces and tabs may go at the beginning, the end,
or next to any space or tab. Also, case is not
significant inside variable names. Thus, a variable named
"Foo" could be accessed with QFOO, Q foo or (if there
is no FO or FOX, etc.) with Q Fo. Because of this
latitude, variables are not created if they are referenced
and do not exist; instead, they must be entered explicitly
in the symbol table by the user. This is easy to do,
because the entire symbol table data structure is
user-accessible; it is an FO-style symbol table that lives
in q-register ..Q. See the FO command for a sample macro
for creating variables. The symbol table must have at least
two words per entry, but it may have more. The additional
words can be used however you like. The FS VARMAC feature
allows the third word to be used to hold a macro to be run
when the value of the variable is changed, but this is enabled
only if FS VAR MACRO is set nonzero. See its definition.
The elements of a q-vector may be accessed as q-registers
in their own right. If q-reg A contains a q-vector, then
the "q-register" :A(0) is the first element of it, and
:A(1) is the second, etc. Indexing starts at zero for the
first element of the q-vector, but only those elements
within the virtual boundaries of the q-vector may be accessed.
See FS QVECTOR for how to create q-vectors.
A star ("*") may be used only with commands like ] and X
that wish only to store in a q-register; it causes such
commands to return their data as a value instead. Thus,
:I*FOO returns a string containing FOO.
Expressions in parentheses can be used only with
commands that wish only to examine the contents of a
q-register; the value of the expression is used as
the contents to be examined. Commands that allow
this option include F^A, F^E, F=, FQ, F~, G and M.
Thus, G(Q0) is equivalent to plain G0.
Q-reg names containing ^R or ^^ refer to the definitions
of ^R-mode command characters. When "^R" is used,
the ^R-mode definition of the specified ASCII
character is referred to; when "^^" is used, the
^R mode definition of the specified charcter xor'ed
with 100 (octal) is meant. The periods specify the
control and meta bits since ^R-mode definitions
belong to 9-bit characters but only 7-bit characters
can be inside TECO command strings; one period sets the
control bit; 2, the meta bit; 3, both control and meta.
If the char is obtained from a ^]^V, then all 9 bits
may be obtained from that source; the periods xor into
the number in the q-reg.
For example, "Q^RA" refers to the definition of "A",
and "Q.^RA" refers to that of control-A, as does
"Q^R^]^VX" when QX holds 301 (octal).
"Q^R^A" refers to the definition of downarrow,
one of the new TV printing characters, as does "Q^^A".
"Q^^J" refers to the definition of linefeed, whereas
"Q.^RJ" refers to the definition of control-J, which
can be typed in only on a TV (and which is usually
defined to execute the definition of linefeed).
R move pointer left arg chars (no arg, same as arg=1).
:R is to R as :S is to S; as :C is to C.
<m>,<n>r
does "<m>+<n>-.J". This is for FLR to work.
S search. Takes following text string
and looks for it in the buffer,
starting from the pointer.
(if the string arg is null, the last nonnull arg
to any search command is used)
if it finds it, it positions the
pointer after the string. If it
does not find it, it does not
move the pointer but generates an
error message unless the search is
inside an iteration (see <. See also FS S ERROR
which may be used to disable this "feature").
If the search is inside an iteration,
the value as if produced by :s (read on)
will be saved whether or not the
colon is used, for use by the ;
command. The effect of iterations on searches is
cancelled by errsets, so what matters is whether
the search is more closely contained in an iteration
or in an errset.
A positive arg to the search means do it arg times,
i.e., find the argth appearance of the string;
a negative arg means search the buffer
backwards from the pointer and
position the pointer to the left of
the string if successful. If the S is
preceded by "@", the char after
the S is used to delimit the text
string instead of altmode. In this case, a null
arg causes a search for the null string, instead of
a search for the last string searched for.
(this for the sake of macro-writers using ^])
if the s is preceded by :, val=-1 if the
search is successful and val=0 if
not--there is no error condition.
Note also the FB, N and _ commands, and the ^B command.
There are some special characters which, when used inside
search strings, do not have their normal meanings unless
quoted with a ^Q:
^X matches any character.
^B matches any delimiter char (normally this means it
matches any non-squoze char, but see q-reg ..D).
^N matches any char other than the char that follows it in
the search string. ^N^B matches non-delimiters, and
^N^X matches nothing. ^N^Q^B matches all but ^B, etc.
^O divides the string into substrings searched for
simultaneously. Any one of these strings, if found, satisfies
the search. Thus, SFOO^OBAR looks for FOO or BAR.
If ^O is used inside a :S, finding the <n>th substring makes
the search return -<n> as its value.
^Q quotes the following char, i.e.,
deprives it of special significance.
In addition, ^] is special as usual.
Note that SFOO^O will always succeed, and will move point
forward over the next three characters
if and only if they are FOO. -2-(:SFOO^O) will do that and
also return nonzero only if they were FOO.
T type: takes one or two args like K
and types out the selected chars.
@T types in the echo area.
U:
<n>U<q>
puts the number <n> in q register <q>.
Returns no value.
<m>,<n>U<q>
puts <n> in <q>, and returns <m>.
Thus "<m>,<n> U<q1> U<q2>" does "<n>U<q1> <m>U<q2>".
V takes arg like K and displays chars, representing
the cursor by "/\" (or whatever is in ..A).
When, after being proceded from a --MORE--,
a new screenfull is started, the place it began
is remembered in FS WINDOW so that an attempt
to display the buffer will try to start at the same place.
This may make redisplay unnecessary if you search for
something that appears on the screen.
Nothing is typed on printing terminals.
@V performs standard buffer display.
That is, "@V" always does what automatic buffer
display does as a default (when ..B holds 0).
When in ^R mode, @V does a ^R-style display.
Note that @V will display on any type of terminal,
although TECO does not normally display automatically
on printing terminals.
In ^R mode, @V treats its arguments as ^R does
(as hints on how to redisplay). When not inside a ^R,
@V ignores its arguments.
If V is followed by W it becomes
VW which does V, then waits for terminal
input of one char whose 7-bit ASCII
value is returned as val.
W flushes current value except when
part of VW or PW.
X takes one or two args like K and
enters selected chars as text into
q-register named by next char in
command string. Can be retrieved
by G command and ^] substitution, q.v.
@X acts like X but
appends text to q-reg rather than
replacing q-reg contents. If q-reg
does not already contain text this
works like ordinary X.
See also :I.
Y kills the buffer, then inserts one page from the
current input file (until first formfeed or eof).
Point is left at the beginning of the buffer.
If reading is terminated by a ^L, the ^L will go in
the buffer iff FS ^LINSERT is nonzero.
(FS ^LINSERT is initially 0)
The input file is not closed, even if eof is reached.
To close the input file, use EC. However, EE does
close the input file. Closing the input file is not
necessary but will lighten the drain on system resources.
Trailing ^C's or ^@'s just before eof are considered
padding and are flushed. To do input without having
any padding characters removed, use FY.
The virtual buffer boundaries are understood.
If no file is open, the buffer is left empty.
Because Y is an easy command to be screwed by, and
isn't really necessary since the A command exists,
there is a way to disable it. See FS YDISABLE.
@Y yanks in all the rest of the file.
^L's within the file go in the buffer.
A ^L at the end of the file will go in the buffer
iff FS ^LINSERT is nonzero. Trailing ^C's and ^@'s
are conidered padding, and flushed.
The input file is closed automatically.
Z val=number of chars in buffer (more generally, the
character number of the virtual end of the buffer,
if virtual buffer boundaries are in use).
[<q> push text or number in q-reg <q> onto the q-register pdl.
There is only one q-reg pdl, not one per q-reg.
At various times (for example, the ^\ and F; commands,
and after errors) TECO unwinds the q-reg pdl to a
previous level by popping everything back to where it was
pushed from.
The [ command does not allow subscript expressions (such
as "[:A(5)") because automatic unwinding would have no way
to know how to pop the pushed value back where it came from.
If you wish to push the value and don't mind that errors,
etc. won't pop it back, do "[(Q:A(5))" or something similar.
<new>[<q>
is equivalent to [<q> <new>U<q>.
\ Converts digits in the buffer to a number, or vice versa.
If no arg, value is the number represented as decimal digits
to right of pointer in buffer (actually, the input radix
comes from FS IBASE, as with numbers in commands).
:\ allows an optional minus sign.
Moves pointer to right of number.
<n>\ inserts printed representation of <n> in
buffer to right of pointer; usually the number is
"printed" in decimal, but the radix is controlled
by q-reg ..E.
If two args, first specifies field size such that if
2nd is shorter than that many chars
leading blanks will be added.
Sets FS INSLEN to the number of characters inserted.
See "FK" and "^F".
<m>,<n>\
is like <n>\ but pads with leading spaces to <m> columns.
<n>:\ returns a string containing the printed representation of
<n>, in the radix in ..E. Sets FS INSLEN.
<m>,<n>:\
makes a <m> character string, with leading spaces.
]<q> pop from q-register pdl into q-reg <q>.
See the [ command.
^ This command has been replaced by the @ command
but still works. See the @ command.
_ if FS _ DISABLE is 0, then _ is like S,
except at end of buffer do Y command and continue search
until end of file on input or until text string found.
If FS _ DISABLE is 1, "_" is illegal.
If FS _DISABLE is -1, "_" is the same as "-".
Use "F_" in a macro to be sure of doing the search.
Rubout deletes last char typed in, and types
deleted char. Done during type-in,
not during command execution.
If executed (rather hard to do), same as _.
Rubouts are typed out by TECO as ^? (rubout is ctl-?)
Lower case letters are interpreted like
upper case letters when they are commands.
Inside insert and search strings they are
treated as themselves.
Various special topics of interest are treated below
When TECO is started for the first time,
it initializes various data areas, prints its
version number, and initializes several flags associated
with the terminal (by executing FS TTY INIT).
If TECO was started at 2 + the normal starting
address, FS LISPT is set nonzero. Otherwise, it is set to 0.
In either case, TECO looks for a "TECO INIT" file (see below),
executing it as a program if it is found.
When TECO is restarted,
it does not clobber the buffer, q-regs or open files.
It does, however, execute FS TTY INIT which resets some
flags whose preferred setting depend on the type of terminal.
Then, it quits to top level and executes
whatever is in q-reg ..L (unless it is 0).
Init files:
whenever TECO is started for the first time, it checks
for a file <hsname>;<xuname> TECO, for a file <hsname>;* TECO,
and then for the file .TECO.;* TECO. The first one found is
executed as TECO commands. The last of those files is the
default init file. The other two would be personal init files.
The personal init file can do whatever you want.
The only thing the default init file does is interpret command
lines from DDT as follows:
":TECO FOO BAR <cr>" typed at DDT causes
"ET FOO BAR EI ER Y" to be done by TECO --
that is, TECO starts editing FOO BAR.
":TECO FOO <cr>" edits FOO > .
Because COM:.TECO. (INIT) sets FS FNAMSY temporarily.
":TECO <filename><TECO commands> <cr>"
typed at DDT executes " ET <file> <commands> ".
A user's own init file should interpreted the JCL by
reading it in with the "FJ" command. It may have any
command format it wishes except that it should always
respond to "<foo>;" in the JCL by flushing the JCL
(do "@^K^W:JCL<cr>P^V") and loading and executing
<foo>'s init file. See the default init file for how
to do those things.
Dumped macro packages runnable from DDT often also have
init files. Such packages should use FS XUNAME and
FS HSNAME to determine init file names the same way TECO
does.
TECO's Data Structures (Strings, Buffers and Qvectors)
TECO has two different data structures for storing sequences of
characters: strings, and buffers. They differ in what operations are
allowed on them, and how efficient they are.
Strings have less overhead than buffers, but as a penalty they are
not easily altered. Once a string has been created, its contents
usually do not change; instead one might eventually discard the
string and create a new one with updated contents. The sole exception
is F^E, which makes it possible to alter characters in a string (but
not to insert or delete). Commands which "put text in a q-register"
all do so by consing up a string and putting a pointer to it in the
q-register.
Buffers are designed to be convenient for insertion and deletion.
Each buffer has its own pointer, and its own virtual buffer
boundaries, which are always associated with it. The contents of a
buffer can be accessed just like the contents of a string (in which
case only the part between the virtual boundaries is visible), but it
can also be "selected" and then accessed or altered in many other
ways: insertion, deletion, searching, etc. Each buffer also has a
flag which is set nonzero whenever the buffer's contents are changed;
it can also be set by the user with FS MODIFIED. A buffer has about
42 characters of overhead, and the number of buffers is limited (about
40). Initially, there is only one buffer in a TECO (pointers to which
are initially found in q-registers ..O and ..Z), and new ones are only
made when explicitly asked for with F[ B BIND, FS B CONS or FS B
CREATE.
Strings and buffers are normally represented in TECO by pointers.
When a q-register "contains" a string, it actually contains a pointer
to the string (see the sections on internal format for details). If
q-register A contains a string, QA returns the pointer, which can be
stored into q-register B; then QB and QA both point to the same
string. The command :I*<string> returns a pointer to a newly consed
up string containing <string>. :G can be used to extract a substring
(which is copied, not shared). The commands :\, :F6 and X* are also
useful for creating strings.
A buffer is selected by putting a copy of a pointer to it into
q-register ..O. TECO has a garbage collector, so that if all pointers
to a buffer or string are eliminated, the storage it occupies will
eventually be reclaimed. Most of the space occupied by a buffer can
be reclaimed explicitly with the FS B KILL command; the buffer is
becomes "dead", and even though pointers to it may still exist, any
attempt to use them to select the buffer or examine its contents will
be an error.
Vectors of objects can also be represented in TECO, with either
buffers or qvectors. Buffers can be used to as vectors of numbers,
while qvectors are used as vectors of arbitrary objects (numbers, or
pointers to strings, buffers or qvectors). The difference is due to
the fact that the garbage collector knows that the objects in a
qvector might be pointers and therefore must be marked, while the
objects in a buffer cannot be pointers and are ignored. The words in
a buffer or q-vector can be accessed easily with subscripted
q-register names; if QA contains a q-vector, then Q:A(0) is its first
element. To access the elements in hairier ways, you can select the
buffer or q-vector and the insert or delete, etc. Q-vectors are
created by means of FS Q VECTOR.
The buffer block, and what buffers contain (and the gap):
The current buffer is described by the 7-word
"buffer block" which contains these variables:
BEG char addr of start of buffer,
BEGV char addr of lower buffer boundary,
PT char addr of pointer,
GPT char addr of start of gap,
ZV char addr of upper buffer boundary,
Z char addr of top of buffer,
EXTRAC # chars in gap.
(next come 2 words used by the communication
protocol. See below).
MODIFF nonzero if buffer has been modified.
RDONLY value of FS READ ONLY for this buffer.
Note that all character addresses normally used in
TECO have BEG subtracted from them; "B" returns
BEGV-BEG; "Z", ZV-BEG; "FS Z", Z-BEG; ".", PT-BEG;
"FS GAP LOCATION", GPT-BEG. "FS GAP LENGTH" gives EXTRAC.
The actual value of BEG is available as "FS REAL ADDRESS".
GPT and EXTRAC describe the "gap", a block of unused space in the
middle of the buffer. The real amount of space used by the buffer is
Z-BEG+EXTRAC. BEGV, PT, Z and ZV are "virtual" addresses in that they
take no account of the gap. To convert a virtual address to a real
one, add EXTRAC to it if it is greater than or equal to GPT. Real
address 0 refers to the first character in word 0; real address 5
refers to the first character in word 1, etc.
It is OK for the superior to alter those variables or the contents
of the buffer, if TECO is between commands or has returned because of
^K, FS EXIT or ^C; except that BEG should not be changed and the sum
of Z and EXTRAC (the real address of the end of the buffer) should not
be changed, unless appropriate relocation of other buffers and TECO
variables is undertaken. TECO programs need not worry about the gap,
except for efficiency reasons or when communicating with machine
language programs, and they need never convert character addresses to
real addresses; TECO does all that.
Strings - internal format:
A string containing <n> characters takes up <n>+4 consecutive
characters in TECO. It need not start on a word boundary. The
first four characters are the string header; the rest, the text of
the string. The header starts with a rubout. The second character
is <n>&177; the third, (<n>/200)&177; the fourth, <n>/40000
(numbers in octal).
Buffers - internal format:
A buffer consists of a buffer-string, which points to
a buffer frame, which points to the buffer's text.
The buffer-string is similar to a string, and exists in a string
storage space, but begins with a "~" (ASCII 176) instead of a rubout.
It has only three more characers; the second is <addr>&177; the
third, (<addr>/200)&177; the fourth, <addr>/40000; <addr> being the
address of the buffer frame.
The buffer frame is a seven-word block whose purpose is
to save the buffer block for buffers which are not selected.
While a buffer is selected, the buffer frame contents may
not be up to date.
The first word of the frame contains a few flag bits in the left
half. The sign bit will be set to indicate that the block is in use
as a buffer frame. The 200000 bit is the GC mark bit and should be
ignored. The 100000 bit, if set, indicates that the buffer is really
a qvector. The 40000 bit is the "buffer modified" flag. These bits
are only in the buffer frame, not the buffer block (BEG).
Buffer and string pointers - internal format:
When a q-reg is said to hold a buffer or a string, it really
contains a pointer to the buffer or string. The pointer is in fact
a number, distinguished from other numbers by its value only! A
range of the smallest negative numbers are considered to be pointers
(this is why QAUB copies a string pointer from QA to QB without any
special hair).
Numbers which are pointers are decoded by subtracting 400000000000
octal (the smallest negative integer) to get a character address.
This may either be the exact address of a character in pure space
(what :EJ loads into), or the relative address of a character in
impure string space (what "X" allocates within. The char address of
the start of impure string space is held in location QRBUF). In
either case, that character should be the rubout beginning a string
or the "~" starting a buffer-string. If the number, thus decoded,
does not point within either of those ranges, or doesn't point at
a "~" or rubout, then it is not a pointer - just a plain number.
For example, 400000000000.+(FS :EJPAGE*5*2000.) is a string
pointer to a string whose first character is at the very beginning
of the last :EJ'd file. If the file has the proper format (see
"strings" above), that number may be put in a q-reg and the string
then executed with "M" or gotten by "G", etc. The file might
contain a buffer-string except that causing it to point to a
legitimate buffer frame would be difficult. Making it point to a
counterfeit buffer frame inside the file would lose, since TECO
tries to write in buffer frames.
Low Bits:
On ITS, the low bits of the words of a "text" file are
generally ignored, but on other systems such as BOTTOMS-10
any word whose low bit is 1 is effectively not present
in the file. Because of this, TECO attempts not to turn
on the low bits of files. However, for efficiency's sake,
low bits are not cleared in files when they are read in;
also, you can easily set low bit explicitly using FS WORD
or U:<buffer>(<idx>). If you wish specifically to clear
the low bits of all the words of the buffer, you can do
it as follows: J 0I ZJ 0I JD ZJ-D.
On the other hand, when you have numeric data in a buffer,
stored in words instead of as text, you must be careful
to avoid operations which can clear the low bits of the words.
Anything which moves text except on word boundaries can
shuffle the positions of the characters in the words, and
the low bits will be misplaced if not also cleared.
You can avoid such problems if you never insert or delete
characters except in groups of 5 or multiples of 5, starting
at positions which are multiples of 5. In this context, note that
5,0I will NOT clear the low bit; you must do 0,.-5FS WORD
or 0U:..Q(<n>) (or something else suitable) to do that.
How superiors can put text (and other things) into TECO:
A standard protocol for communication from a superior to TECO
is hereby defined, which allows the superior to request space
in the buffer for inserting text, or request that a file be
loaded and a certain function be found. Macro packages may
supply functions to handle the requests instead of TECO's default
handler.
A superior can make a request whenever TECO has deliberately
returned control (by a ^K valret, FS EXIT or a ^C) by restarting
TECO at a special place: 7 plus the address of the "buffer block",
which address can be found in accumulator 2 at such times.
Save the old PC before setting it, since you must restore the PC
after the request is handled. The word after the starting location
(8 plus the buffer block address) is used for an argument.
There are two types of requests. If you wish to supply
text for TECO to edit, the argument should be the number of
characters of text you need space for (it may be 0). In that case,
TECO will return (with an FS EXIT) after making at least that
much space in the buffer, after which you should restore the PC
at which TECO had stopped before you made the request. You can
then insert the text in the buffer and restart TECO.
If you want TECO to read in a file, supply a negative argument
and be prepared to supply TECO with JCL, when it asks with the
standard .BREAK 12, describing what it should do. When TECO does
a .BREAK 16, (FS EXIT) you can assume it has done its work,
and should restore the old PC. The formats for the JCL string are
<filename><cr>, <filename>,<decimal number><cr>, and
<filename>,<function name><cr>. A decimal number should be the
address within TECO of the place to start editing. A function name
can be anything that isn't a number, and its interpretation is not
specified.
TECO macro packages can supply a handler for requests from the
superior by putting it in FS SUPERIOR. It will receive the
argument describing the type of request as its numeric argument
(^Y), and can read the JCL with FJ and do an FS EXIT when finished.
If FS SUPERIOR is zero, TECO's default actions will be taken
Note that TECO's default handling of a request to load a file is
to do nothing.
TECO's character sets:
(numbers in this section are in octal)
The most important TECO character sets are ASCII (7-bit)
and the 9-bit TV set. The contents of all files, strings,
and buffers, and thus all TECO commands, are in ASCII;
9-bit is used only for terminal input. Here is how TECO
converts between character sets:
14-bit to 9-bit conversion when characters are read in:
When a character is actually read from the terminal, it is in
a 14-bit character set which contains a basic 7-bit code,
and the control, meta and top bits (also shift and shift-
lock, which are ignored since they are already merged into
the basic 7-bit character). TECO converts it to 9-bit
as follows: if top is 0, and the 7-bit character
is less than 40 and not bs, tab, LF, CR or altmode,
then add control+100; then clear out top, shift and shift-lock.
Thus, TV uparrow comes in as top+013 and turns into 013;
TV control-K comes in as control+113 and stays control+113;
TV "VT" comes in as 013 and turns into control+113;
TV control-VT comes in as control+013 and becomes control+113;
non-TV control-K comes in as 013 and becomes control+113;
TV control-I comes in as control+111 and stays control+111;
TV "tab" comes in as 011 and stays 011;
TV control-tab comes in as control+011 and stays control+011;
non-TV "tab" or control-I comes in as 011 and stays 011.
The character 4110 (Top-H) is the HEL character; it is
handled specially. It is not changed, even when any other
character would be converted to 9-bit or 7-bit. It is always
returned as 4110. However, if FS HELP MAC is nonzero, then
4110 typed AT ANY TIME will cause FS HELP MAC to be run.
When FS HELP MAC is run, the 4110 is otherwise ignored, so
TECO will continue to wait for input (unless FS HELP MAC
sets FS REREAD to supply some). Only when FS HELP MAC is
zero will 4110 ever be returned to the user. ^R ignores
4110 (except for running FS HELP MAC).
9-bit to ASCII, when TECO wants to read an ASCII code:
input read in using "@FI", or read by the ^R-mode
comand dispatch, is used as 9-bit. However,
when input is read by "FI", or by the "^T" command reader,
or by TECO top level, it must be converted to ASCII
as follows: meta is thrown away; if control is 0 then
nothing changes; otherwise, control is cleared and the
following actions performed on the 7-bit character that
is left: rubout stays the same; characters less than 40
stay the same; characters more than 137 have 140 subtracted;
characters 100 to 137 have 100 subtracted; all others
are unchanged, except for 40 (Space) which becomes 0 (^@).
Thus, control+111 (TV control-I) becomes 011;
control+011 (TV control-tab) becomes 011;
and 011 (TV tab, or non-TV control-I) stays 011.
Similarly, TV uparrow, TV "VT", TV control-K and non-TV
control-K all become 013.
ASCII to 9-bit in FS ^RCMACRO and FS ^R INIT:
The ^R command dispatch table is indexed by 9-bit
characters. For compatibility with the time that it was
not, the commands FS ^R CMACRO and FS ^R INIT, when
not given the atsign modifier, accept an ASCII argument,
and try to have the effect of referring to the definition
of that ASCII character - in fact, they convert the ASCII
character to 9-bit and then index their tables. The
conversion is as follows:
if the character is less than 40, and is not bs, tab,
LF, CR or altmode, then add control+100.
Thus, 013 (^K) becomes control+113 (TV "VT" or control-K,
not TV "uparrow"), which is just right. Tab, etc. have
a harder time doing the right thing, since both 011
control+111 are plausible ways that the user could type
what corresponds to ASCII 011. The solution chosen is
to leave 011 ASCII the same in 9-bit, since the ^R-mode
definition of control-111 is to use 011's definition.
The initial ^R-mode definitions of all 9-bit characters:
All characters whose bottom 7 bits form a lower case
letter are defined to indirect through the corresponding
upper case character. Their definitions are all
40,,RRINDR, where RRINDR is the indirect-definition routine,
and 40 specifies the character 40 less.
Control-BS and Control-H indirect through BS, and similarly
for Tab and LF. Control-CR and Control-Altmode (but not
Control-M and Control-[) indirect through CR and Altmode.
An isomorphic indirection-pattern exists for meta characters.
Control-, Meta- and Control-Meta-digits all accumulate into
the numeric argument.
Control-, Meta- and Control-Meta-Minus-sign all set the
4 bit in FS ^R ARGP, thus negating the next command's arg.
All other meta characters are self-inserting. A few
(mentioned above) are self inserting because they go indirect
through other meta characters.
All non-control non-meta characters, except for CR,
altmode and rubout, are self-inserting. CR inserts CRLF;
altmode leaves ^R-mode; rubout deletes backwards.
Of the rest, ^H, ^I and ^J are defined to insert themeselves
straight away, while the rest are defined to be "normal"
and do whatever FS ^R NORMAL and FS ^R REPLACE say.
Control-rubout has its own special routine, which deletes
treating spaces as if they were tabs.
Control-digits update the numeric arg for the next command.
All other control characters not in the range
control+101 through control+135 are errors.
Control-M inserts just a CR. Control-[ is an error.
The remaining control characters from control-101 to
control-135 do what the ^R command table says, or else are
errors.
Neat hacks that are frequently useful:
1) To take an absolue value, use ^@^@. -1^@^@ and 1^@^@ are both 1.
This assumes that there is no pre-comma argument.
2) When there is just a pre-comma argument, :^@ will make it a
post-comma argument instead. There will be zero as a pre-comma
argument, but another ^@ will flush that. Thus, :^@^@ gets a
pre-comma argument as a post-comma argument with no pre-comma.
If there is a post-comma argument already, start with *0 to clear it
first, giving *0:^@^@.
Since many commands ignore pre-comma arguments, simply :^@ may be
enough.
3) ",0^@" negates its argument, like "*(-1)".
4) The easiest way to compute the maximum of two quantities is with
F^@, as in QA,QBF^@. This, however, returns the other one as a
pre-comma argument. For the minimum as a post-comma arg, add :^@.
TECO program writing standards:
1) Each line that doesn't begin inside a string argument
should be indented with at least one space,
preferably with a number of spaces
indicating how deep in conditionals and
iterations it is.
2) The semantic content of one line of TECO program
should be no greater than that of one line of any
other language, if the program is to be understandable.
in other words, break lines frequently - and put a
comment on each line. There should be spaces
between logical groups of commands, every few characters,
as in "3K J IFOO", which also shows how long a line
should be.
3) The standard way to write a comment is to make it
look like a tag: !<comment>!.
4) Follow value-returning commands with "W"'s or CRLFs
when the value is not used for anything.
5) An example of a well-commented TECO program is RMAIL.
See EMACS1;RMAILX > and RMAILZ >. Note that these are
written in EMACS compressor format.
TECO program debugging aids:
1) Trace mode causes all TECO commands to be typed
out as they are executed. See the "?" command.
A good technique is " 1F[TRACE MA " for running
q-reg A in trace mode.
2) FS STEP MACRO causes TECO to pause at each line,
displaying the buffer and waiting for input before
continuing execution. This works best when lines
are short, as they ought to be anyway.
3) Break-loops on errors are available, by setting
FS *RSET to nonzero, or by using Q..P.
4) It is easy to edit a "FTHere I am" or "Q0=" into
the program and re-execute it.
5) If the standard top level is in use, "?" typed in
after an error will cause a printout of a short
section of command string up to the point of the error.
User break loops in Q..P can use FS BACKTRACE to do
similar or better things.
6) Setting FS .CLRMODE to 1 disables the ^L and F+
commands, which normally clear the screen. This may
be useful for debugging programs that wipe out their
trace output.
Local Modes:
Mode:Text
Fill Column:70
Space Indent Flag:1
Paragraph Delimiter:
:m.m ^R Indent Relative
End: