Undocumented OpenVMS: SYS$SIGPRC

This routine sends a signal to a process similar to the C-RTL kill function introduced with OpenVMS 7.x.
The function prototype looks like this:
int sys$sigprc(int *pid, struct dsc$descriptor_s *prcname, int code);

Special PID values

PID=0 sends a signal to your own process. Unlike from what one might expect from the behaviour of UNIX kill, a PID less than zero results in a NONEXPR, non existant process error (independent of the privileges the current process holds).

Privilege checking

Concerning privilege checking sys$sigprc seems to behave like sys$forcex, the status will be returned in R0 with the error code (at least if you did not kill your own process using PID 0 ;-)

Example Code

/* test sys$sigprc, sends a SS$_ABORT to selected process */
#include <stdio.h>
#include <descrip.h>
#include <ssdef.h>
#include <lib$routines.h>

int
main(int argc, char* argv[])
{
  int pid=0, iss;
  int sys$sigprc(int *pid, struct dsc$descriptor_s *prcname, int code);
  
  if (argc < 2) {
    printf("Usage: sigprc PID\n");
    return SS$_NORMAL;
  }
  sscanf(argv[1], "%x", &pid);
  
  printf("Sending ABORT to PID %08x\n",pid);
  
  iss = sys$sigprc(&pid,0,SS$_ABORT);
  if (!(iss&1)) lib$signal(iss);
  return SS$_NORMAL;
}

Comments to: Martin P.J. Zinser
Last modified: 20020628