Trailing-Edge
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PDP-10 Archives
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SRI_NIC_PERM_FS_1_19910112
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kcc-4/lib/usys/signal.c
There are 8 other files named signal.c in the archive. Click here to see a list.
/* SIGNAL - Simulate 4.3BSD signal mechanism, via sigvec()
**
** Copyright (c) 1987 by Ken Harrenstien, SRI International
**
** See the file SIGNAL.DOC for more background information on this code.
*/
#include "c-env.h"
#include "errno.h"
#include "signal.h"
#include "sys/usysig.h" /* USYS_ macros */
typedef void (*hndlr_t)(); /* Type of sv_handler (for convenience) */
hndlr_t
signal(sig, func)
int sig;
hndlr_t func;
{
struct sigvec sv;
hndlr_t ofunc;
USYS_BEG();
if (sigvec(sig, (struct sigvec *)0, &sv) != 0) /* Get old sigvec */
USYS_RET(SIG_ERR); /* errno already set to EINVAL by sigvec() */
ofunc = sv.sv_handler; /* Remember old handler */
sv.sv_handler = func; /* Set up new sigvec for this signal */
if (sigvec(sig, &sv, (struct sigvec *)0) != 0) /* Set new sigvec */
USYS_RET(SIG_ERR);
USYS_RET(ofunc); /* Won, return previous handler */
}