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                             AN INTRODUCTION TO MIC

     MIC stands for Macro Interpreted Commands and is a system that  allows
     users to create their own system commands.

     This User Guide is intended as an introduction  to  MIC;   it  is  not
     intended as a reference document.  A MIC reference manual is available
     for a small fee from the Job Receptionist and a copy is  held  in  the
     user  area  book  racks.   A MIC Summary Card is also available (free)
     from Job Reception.

     keywords:  MIC, macro commands, command files

                                                              J.D. Service
                                                              A.J. Bullen

          CONTENTS                                                    page

     1.  What MIC does                                                 2
     2.  Creating MIC files                                            3
     3.  Calling MIC files                                             3
     4.  Example                                                       4
     5.  Parameters in MIC macro commands                              4
     6.  Labels and branching facilities                               6
     7.  Error detection and processing                                7
     8.  Silencing MIC                                                10
     9.  Manipulating parameters in a command file                    11
     10. Character subscripting facilities                            11
     11. Other useful facilities                                      12
     12. Miscellaneous notes on MIC                                   13
     13. Commands not covered in this guide                           13

This is a reprint with minor changes of the version dated 1 September 1978.
Replacement is not necessary.
     User Guide No. U6                                               Page 2
     14 November 1979

 1.  What MIC does.

     MIC is particularly useful if you are a regular user of the system and
     find  that  you  are  frequently typing the same sequence of commands,
     which is boring.  What you require is a single command which  performs
     the  functions  of  all  of your commands.  In computer jargon this is
     called a MACRO command, and on the DEC-10 they are known as

          macro commands
     or   MIC commands
     or   MIC command files.

     For example if you frequently use the sequence of commands:

          .DELETE *.TMP,*.Q??

     you could create a macro command called SNOOPY, say, to perform  their
     combined function.  

     To do this, SOS or TECO (see User Guide U2 for SOS  or  U1  for  TECO)
     could  be used to create a file, called a MIC file, containing the two
     commands (including the full stops at the start  of  the  lines).   If
     this  file was called SNOOPY.MIC - note the .MIC extension - you could
     cause the sequence of commands to  be  obeyed  simply  by  typing  the
     single command

          .DO SNOOPY

     The commands in the MIC file will then be typed on your  terminal  and
     obeyed  as  if  you had typed them;  all output from the commands will
     also be displayed on the  terminal.   The  file  SNOOPY.MIC  can  then
     remain available for use at any time.

     MIC files may contain any number of commands, of any  type,  including
     macro  commands.  In order to make MIC commands more useful, MIC files
     may  use  many  other  facilities,  including  command  arguments  (or
     parameters)   and  switches  in  the  command  call,  conditional  and
     branching statements to enable jumps to labelled lines, and assignment
     statements  which  allow  parameters  and  variables to be assigned or
     altered during the processing of the MIC command.
     User Guide No. U6                                               Page 3
     14 November 1979

 2.  Creating MIC files.

     MIC files may be created using a normal text file editor, e.g.  SOS or
     TECO.  The file may be with or without line numbers.  It will normally
     have the extension .MIC.

     Each line should have as its first non-space or tab character  one  of
     the characters =, ., *, !  or ; which are interpreted as follows:

          .    monitor command follows
          *    data to be input to a program follows
          =    ignore carriage return at the end of this line
          !    comment line follows
          ;    comment line follows (see section 8 for difference from !)

     In order to get control characters such as  control-C,  control-Z,  or
     altmode  into  a  MIC  file,  the  control  key  and the character are
     replaced by the up-arrow key followed by the character, e.g.

          ^C for control-C
          ^Z for control-Z
          ^[ for altmode (escape)

     The ' (single  quotation  mark)  followed  by  a  letter  indicates  a
     parameter in MIC (see section 5) so if quotation marks are needed in a
     MIC file it is advisable to use double quotes ("<text>").

     If any of the special characters described in this section is required
     as itself, however, the character should be repeated, e.g.

          ^^C                        gives ^C not control-C.
          VID:``MYTAPE'              gives VID:`MYTAPE' not parameter M

     Note - the characters =, ., *, !, and ;  need only be repeated if they
     are required in the first character position of a line.

 3.  Calling MIC files.

     MIC files are called into action with a command of the form

          ./<dev>:<micfilename>[<ppn>]      .DO <dev>:<micfilename>[<ppn>]

     where the device, ppn and file extension are optional.  If the file is
     in your own disk area or in the MIC library area (MIC:), the following
     is sufficient:

          ./<micfilename>      .DO <micfilename>
     User Guide No. U6                                               Page 4
     14 November 1979

     because the defaults are

          DSK:, or if not found, MIC:, for device
          your own project-programmer number for [<ppn>]
          .MIC for the filename extension.

 4.  Example.

     The following is an example of a computer session to create and use  a
     MIC file to tidy up one user's disk area:

          .MAKE TIDY.MIC           Call TECO to make a file called TIDY.MIC.
          *I.DELETE *.BAK          Insert monitor commands as shown ...
          .PROTECT *.DAT <177>     
          .PRINT *.LST             
           $ $
          *EX $ $                  Exit from TECO.

          .DO TIDY                 Call TIDY.MIC into action
          .DELETE *.BAK            From this point on, the system 
          FILES DELETED            obeys your MIC file automatically.
          FIND.BAK                 The remainder of the example has 
          10 BLOCKS FREED          been output in its entirety by 
          .PROTECT *.DAT <177>     the system with no input from you.
          .PRINT *.LST
          [LPT:<filename>=/Seq:2601/Limit:203,4 Files]

 5.  Parameters in MIC macro commands.

     More generalised commands may be constructed using parameters  in  the
     MIC  file  to  stand  for filenames or other quantities which would be
     entered in the MIC command command call.  The full specification of  a
     MIC call is

          ./<dev>:<micfilespec>[<ppn>] <parameterA>, <parameterB>, ...
          .DO <dev>:<micfilespec>[<ppn>] <parameterA>, <parameterB>, ...

     A parameter may be  any  string  of  characters  separated  by  commas
     (special rules exist for brackets - see the MIC Reference Manual).  Up
     to 26 parameters are allowed and within the MIC file itself  they  are
     introduced  by  'A,  'B,  'C  ....'Z,  i.e.   a letter of the alphabet
     preceded by a single quote.  During execution  of  a  macro  a  single
     quote  followed  by  the  <n>th  letter of the alphabet will always be
     replaced by the <n>th parameter in the MIC call.  
     User Guide No. U6                                               Page 5
     14 November 1979

     As an example, the TIDY macro described earlier changed the protection
     code  of all .DAT files to 177.  The actual protection code used could
     have been selected at run time  by  giving  the  required  code  as  a
     parameter in the MIC call.  To do this the MIC file should contain

          .DELETE *.BAK
          .PROTECT *.DAT <'A>
          .PRINT *.LST

     To obtain a protection of 177 the MIC call is

          .DO TIDY 177

     To obtain a protection of 157 the MIC call is

          .DO TIDY 157

     In the first case 177 is substituted for  'A  at  run  time;   in  the
     second case 157 is substituted.

     Parameters are very useful when setting up MIC files which will act on
     file  names  at run time;  the parameters will then be file names.  As
     an example consider the problem of retrieving a file from  a  magnetic
     tape.   First  the magnetic tape must be mounted, then the file copied
     to disk.  Finally you may want to see that the file  has  really  been
     retrieved by checking your directory listing.  It is possible to write
     a retrieval macro called, say, RESTOR, which would  perform  the  task
     when you give a command of the form

          ./RESTOR <filename>.<ext>      .DO RESTOR <filename>.<ext>

     The commands in RESTOR.MIC would be

          .R BACKUP
          *RESTORE 'A

     When the MIC command call

          .DO RESTOR PROG1.F4

     is typed, PROG1.F4 would be substituted for 'A in  the  processing  of
     the macro.

     The example can be further generalised by  using  parameters  for  the
     tape identity.  In this case RESTOR.MIC would contain

          .R BACKUP
          *RESTORE 'A
     User Guide No. U6                                               Page 6
     14 November 1979

     and a MIC call would be of the form


 6.  Labels and branching facilities.

     The normal sequential processing of a MIC file may be  interrupted  by
     using  jump  commands  to  labelled  lines.   Conditional  statements,
     described later, allow a conditional jump or a conditional command  to
     be included.


         These jump commands and conditional statements, as well as the
         error  processing  features  described  in section 7, have the
         same names and functions as those used by the batch system.

     6.1  Labels.

     A line in MIC may be labelled by placing the label at the beginning of
     the  line.  A label consists of one to six alphanumeric characters and
     is terminated by a double colon (::).  Example -

          FRED::.DELETE *.BAK

     6.2  Jump statements.

     Two jump statements are available:

     and  .BACKTO      

     The GOTO statement is used for a forward branch and the BACKTO  for  a
     backward branch.  (`Backward' here means going to the beginning of the
     file and starting the search from there.)

     A not to be recommended  example  which  will  perform  DIRECT  in  an
     infinite loop is

          .BACKTO FRED
     User Guide No. U6                                               Page 7
     14 November 1979

     Another not very exciting example is

          .GOTO MYLAB
          .DEL *.TMP

     because the .DEL *.TMP will never be obeyed.

     There is one label, %FIN, which acts as a kind of `super label' and is
     branched  to by any GOTO or BACKTO if the %FIN occurs before the label
     for which they are searching.  In the following example,

          .GOTO FRED
          %FIN::.COMP MYPROG.FOR

     the statement GOTO FRED will cause a branch to %FIN rather  than  FRED
     because %FIN occurs before FRED.

 7.  Error detection and processing.

     When a monitor or system program error  occurs  an  error  message  is
     normally  output,  and  this  is  what most sensible user programs do.
     Conventionally error messages are preceded by ?  for fatal errors, and
     %  for warnings, and this `error character' always occurs as the first
     character of an output line.  MIC, like the batch system,  allows  you
     to  monitor  this  first character in the output line and take special
     action if your defined error character occurs in this position.

     By default this facility is off, unless you are running MIC in  batch.
     To use it, you include a command of the form

          .ERROR <character>

     to inform MIC which character in the first character position  of  the
     output  line  is  to  be  regarded  as preceding an error message.  In
     batch, the default  character  is  question  mark  (?).   This  single
     command allows you to introduce very simple error processing into your
     MIC macro.  Whenever the error character specified by the  command  is
     detected, processing of the MIC file will cease and the message

          [ABORT ON ERROR]

     will be displayed.
     User Guide No. U6                                               Page 8
     14 November 1979

     For example if we modify the TIDY macro thus:

          .ERROR ?
          .DELETE *.TMP
          .PROTECT *.DAT <'A>
          .PRINT *.LST

     then if we give an invalid argument to the macro the result will be:

          .DO TIDY 875
          .ERROR ?
          .DELETE *.TMP
          .PROTECT *.DAT <875>
          ?CMLIPC Illegal protection code: 875
          [ABORT ON ERROR]

     Note that the PRINT command has not been obeyed.

     While this is useful it is obviously  more  useful  if  the  user  can
     specify  what  action  is  to  be  taken if an error is detected.  MIC
     provides three ways in which this can be done (only two of  which  are
     described  in this document) and all three may be included in the same

 7.1  Error labels.

     The first method is to  include  error  recovery  labels  at  suitable
     points within the MIC macro.  There are three special labels which may
     be classed as error recovery labels;  "%ERR", "%CERR", and "%FIN".

     On detecting an error character MIC does not actually stop  processing
     the  MIC  file  immediately as was said in the last section, rather it
     searches the remaining part of the MIC file for the occurrence of  one
     of the three error labels.  Which label is searched for depends on the
     following simple rule:

     If the error occurred in a program which  came  from  SYS:   (i.e.   a
     systems  program)  or a monitor command, the label "%CERR" is searched
     for, otherwise the label "%ERR" is searched for.  However  "%FIN"  has
     the  same  super-label  effect described in section 6.2 and if, during
     the search for "%ERR" or "%CERR" a "%FIN" label is  encountered,  this
     will be regarded as satisfying the search.

     Once MIC has found one of these error labels it  `forgets'  about  the
     error  and  continues  processing  the  command  file  from a position
     immediately after the error label.
     User Guide No. U6                                               Page 9
     14 November 1979

     For example if our TIDY macro is modified thus:

          .ERROR ?
          .DELETE *.TMP
          .PROTECT *.DAT <'A>
          %FIN::.PRINT *.LST

     the print command will always be obeyed even if  an  error  occurs  in
     either of the preceeding two commands.

     An alternative form is:

          .ERROR ?
          .DELETE *.TMP
          .PROTECT *.DAT <'A>
          %CERR::.PRINT *.LST

     because DELETE and PROTECT are system commands, but

          .ERROR ?
          .DELETE *.TMP
          .PROTECT *.DAT <'A>
          %ERR::.PRINT *.LST

     is not correct.

     These labels may occur as often as required in a MIC macro as the file
     is always searched forward for error characters.

     For example the following would be a rather silly way of ignoring all
     errors in TIDY:

          .ERROR ?
          %FIN::.DELETE *.TMP
          %FIN::.PROTECT *.DAT <'A>
          %FIN::.PRINT *.LST


          .ERROR ?
          %FIN::.DELETE *.TMP
          %CERR::.PROTECT *.DAT <'A>
          %CERR::.PRINT *.LST

     or any other combination of %CERR and %FIN.

     7.2  Error conditionals.

     The second method of processing errors allows  a  much  finer  control
     over  error  recovery,  and to explain how it works we must once again
     change our explanation of MIC's action on detecting an error.
     User Guide No. U6                                              Page 10
     14 November 1979

     When an error is detected the command file is first searched  for  the
     next  monitor  level  line,  that is the next line starting with a "."
     (see section 2) and if the command on that line is

          .IF (ERROR) <argument>


          .IF (NOERROR) <argument>

     processing of the command file will recommence  with  that  same  "IF"

     If a %FIN or other appropriate error label is found during the  search
     for the next monitor level command the error will be treated as in the
     previous section.  Similarly if the first command line is not  one  of
     the  two  IF  commands  the  error  will be treated as in the previous

     Thus if we modify TIDY yet again -

          .ERROR ?
          .DELETE *.TMP
          .PROTECT *.DAT <'A>
          .IF (ERROR) .DIR/F
          .PRINT *.LST

     then if an error occurs in the PROTECT command the command IF  (ERROR)
     will  cause  the  DIR/F  command  to  be  obeyed followed by the PRINT
     command, but if the error occurs in the DELETE  command  none  of  the
     following commands will be obeyed.

 8.  Silencing MIC.

     Generally the commands in a MIC control file  will  be  typed  on  the
     terminal  as they are obeyed.  However this type-out can be suppressed
     by the MIC command .SILENCE or reinstated by the command .REVIVE.  For

          .R SETSRC

     in a MIC file will suppress the output from the running of SETSRC.

     The whole MIC control file may be silenced by giving it  a  protection
     code  of <2??>, i.e.  any protection with the first digit a `2'.  This
     is over-ridden in the file by  any  .REVIVE  command.   In  the  above
     example this would allow the .SILENCE command to be omitted.

     Note that comments preceeded by "!"  will  be  displayed  despite  the
     SILENCE condition;  those preceeded by ";" will not.
     User Guide No. U6                                              Page 11
     14 November 1979

 9.  Manipulating parameters in a command file.

     Users' parameters to MIC command files are held within  MIC  as  ASCII
     strings.   The  LET  statement  allows a user to change parameters and
     define new parameters during the processing of a MIC file by assigning
     a string or integer expression to the parameter thus:

             .LET <parameter name>=<expression>

     where  <parameter name> is a parameter to the MIC file
            either passed in the calling statement or newly 
            constructed.  It must be one of the characters 
            A through Z.

            <expression> is either a string expression or a
            simple integer expression.

     A string expression may be a simple string such as "FRED.FOR" or  have
     a  more  complex form allowing a string to be constructed from strings
     in  other  parameters;   e.g.   $A+"."+$B  is  an   expression   which
     concatenates  three  strings.   Note  the  use  of  the  $  before the
     parameter to indicate that the contents of the  parameter  are  to  be
     treated as a string, i.e.  $A is equivalent to "'A".

     An integer  expression  may  also  have  parameters  and  involve  the
     arithmetic  operators  + - * / and ^ where the normal precedence rules
     apply.  An example of an integer expression is 3*C+A-B.


         Whenever parameter Z is referred to in future it 
         will contain the text "THIS FORMS A NEW PARAMETER"

     b)  A calling statement of DO LINUS DSKD and statements in
         the MIC file LINUS of
         .LET F="[1045,33]"
         .LET H=$A+"FRED.FOR"+$F
         .EX 'H
         would execute the program DSKD:FRED.FOR[1045,33]

     c)  .LET D=A+1 will add the integer 1 to the integer
         held in A.  If A does not contain an integer an 
         error message will result.

 10. Character subscripting facilities.

     Any single character or  group  of  characters  in  a  string  may  be
     referred  to individually by using the subscripting facilities.  These
     allow you to give a MIC command  which  will  loop  around  a  set  of
     monitor commands substituting a different parameter from a sequence of
     parameters each time the loop is obeyed.
     User Guide No. U6                                              Page 12
     14 November 1979

     A subscripted string expression used in a LET statement has the form


     The first subscript specifies the first character to be extracted from
     the  string contained in the parameter, the second subscript specifies
     the total number of characters to be extracted.

     Thus if parameter A contains the string BCDEF the  subscripted  string
     expression $A.[2,3] refers to the string CDE.

     The second subscript may be omitted and in this case the length of the
     extracted  string  is  assumed  to  be  one character.  The expression
     $A.[4] refers to the 4th character in the string, i.e.  character E in
     the above example.

     Negative subscripts may be used to count backwards from the end of the
     string.  If A contains BCDEFG then $A.[-2] refers to character F.

 11. Other useful facilities.

     11.1  The PLEASE command.

     A PLEASE command (not to be confused with the Batch PLEASE) exists  to
     enable  a  message  to be transmitted to the user of a MIC file.  This
     may be used to indicate progress during the operation  of  a  silenced
     MIC  file or to transmit a message from the creator of a MIC file to a
     user of the file.

     The form of the command is

          .PLEASE <message> $

     The message is displayed on the terminal when the  PLEASE  command  is
     processed in the MIC file.  If the terminating altmode is omitted then
     MIC will suspend processing until you give instructions to proceed  by
     typing control-P - see section 11.2.

     11.2 Suspending MIC processing.

     The processing of a MIC file may be  suspended  by  typing  control-B.
     MIC will then output the message [BREAK] and await further action from

     At this stage any monitor command or any MIC command may be typed  in.
     (If a MIC command is typed in, the initial `.' should be omitted.) You
     may for example wish to type in LET commands to alter  the  values  of
     the parameters in the suspended MIC file or GOTO and BACKTO statements
     to cause jumps to other parts of the MIC file.
     User Guide No. U6                                              Page 13
     14 November 1979

     To continue processing of the MIC file type control-P.  Any changes in
     parameters  or  instructions  to  jump  to  labelled  commands will be
     recognised in the processing of the remainder of the MIC file.

     Note that a control-C typed in during the break period will cancel the
     suspended MIC process.

     11.3 Nested MIC processes

     MIC command files may themselves contain MIC commands.  Each file  may
     have  its own parameters but inner processes may access the parameters
     in an outer process.   For  further  details  see  the  MIC  reference

 12. Miscellaneous notes on MIC.

  a) If a job is currently executing a MIC file, type-ahead is not allowed.
     The  only  exception  is for control characters;  all other type-ahead
     will be discarded.

  b) An existing batch control file can be run as a MIC macro as long as it
     does  not  include single quote characters which MIC will interpret as
     parameter indicators.

 13. Commands not covered in this guide.

     The following MIC facilities are not covered in this  user  guide  but
     are fully documented in the MIC reference manual.

     Multiple LET statements
     IF (command) extensions
     MIC RESPONSE command
     MIC ABORT command
     MIC CANCEL command
     MIC BREAK command
     MIC PROCEED command
     MIC EXIT command
     MIC RETURN command
     Obtaining system parameters such as TTY number, PPN, Job numbers
     ON command
     WHENEVER command
     MIC SET command
     Action parameters
     Multiple commands on a line
     User Guide No. U6                                              Page 14
     14 November 1979

     You are advised to see the MIC reference manual for full documentation
     on  MIC.  A copy is held in the computer building user area book rack,
     and copies may also be obtained from Job Reception for a small fee.