SIGCONT occurs after a SIGTERM

[Paul Falstad]

coleman at cam.nist.gov (Sean Sheridan Coleman X5672) wrote:
>Please explain to me why a SIGCONT is sent to a process after
>SIGTERM is sent to my process. It doesn't compute because TERM
>means to terminate the the process. I catch SIGCONT because I 

This is caused by the following code in csh's sh.proc.c:

         if (signum == SIGTERM || signum == SIGHUP)
            (void) killpg((pid_t) pp->p_jobid, SIGCONT);

There is a good reason for this.  If you kill a stopped process, it
will not die until you send it a SIGCONT (unless you use SIGKILL).
It is counterintuitive for a process not to die when you type
"kill <process>", so somebody just threw in these two lines to have it
send a SIGCONT as well.  For the shell's kill code to not check to see if the
process is actually stopped before sending it a SIGCONT is just sloppy;
also singling out only SIGTERM and SIGHUP for this special treatment is a real
hack IMHO (unless I'm missing something).  Use /bin/kill <pid> which does
not do this.

--
Paul Falstad, pfalstad at phoenix.princeton.edu | 10 PRINT "PRINCETON CS"
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