Re: PATCH: loop killing

[Sven Wischnowsky <wischnow@informatik.hu-berlin.de>]

Peter Stephenson wrote:

> Sven Wischnowsky wrote:
> > This is the solution which executes commands in a loop in the same
> > process group as the parent shell.
> 
> This seems to be the neatest solution, covering most of the common things
> you want to do without any fuss.  But at the moment something nasty is
> happening with shell functions.
> 
> % fn() { less $*; }
> % fn glob.c
> ^Z
> <job disappears completely>

execshfunc() deleted the job before the function was executed,
stealing us the information about it. I'm not too sure about the test
I changed this to... (but it seems to work).

> Hmmm, that didn't seem to be working properly even before, except the
> problem then was that when I tried to continue it I got the message 
>   zsh: 39221 suspended (tty output)  l glob.c
> so it looks like the process groups were already getting messed up.
> So maybe the new problem is just the old one appearing in a different
> place.

Right. The sub-shell for the shell (the super-job) put itself
unconditionally into the group of the gleader of the list_pipe_job --
but in cases like this one the sub-shell itself is the first job that
is entered into it, so gleader wasn't set and the sub-shell ended in
its own little process group which gave us the problem above when the
parent shell tried to foreground the job and used gleader of the
super-job for that.

Bye
 Sven

diff -u os/exec.c Src/exec.c
--- os/exec.c	Thu Jun 24 11:47:25 1999
+++ Src/exec.c	Thu Jun 24 13:40:28 1999
@@ -901,6 +901,9 @@
 		    DPUTS(!list_pipe_pid, "invalid list_pipe_pid");
 		    addproc(list_pipe_pid, list_pipe_text);
 
+		    if (!jn->procs->next)
+			jn->gleader = mypgrp;
+
 		    for (pn = jobtab[jn->other].procs; pn; pn = pn->next)
 			if (WIFSTOPPED(pn->status))
 			    break;
@@ -977,11 +980,13 @@
 		    else {
 			close(synch[0]);
 			entersubsh(Z_ASYNC, 0, 0);
-			setpgrp(0L, mypgrp = jobtab[list_pipe_job].gleader);
+			if (jobtab[list_pipe_job].procs)
+			    setpgrp(0L, mypgrp = jobtab[list_pipe_job].gleader);
 			close(synch[1]);
 			kill(getpid(), SIGSTOP);
 			list_pipe = 0;
 			list_pipe_child = 1;
+			opts[INTERACTIVE] = 0;
 			break;
 		    }
 		}
@@ -2793,14 +2798,13 @@
     if (errflag)
 	return;
 
-    if (!list_pipe) {
+    if (!list_pipe && thisjob != list_pipe_job) {
 	/* Without this deletejob the process table *
 	 * would be filled by a recursive function. */
 	last_file_list = jobtab[thisjob].filelist;
 	jobtab[thisjob].filelist = NULL;
 	deletejob(jobtab + thisjob);
     }
-
     if (isset(XTRACE)) {
 	LinkNode lptr;
 	printprompt4();
diff -u os/signals.c Src/signals.c
--- os/signals.c	Thu Jun 24 11:47:28 1999
+++ Src/signals.c	Thu Jun 24 13:44:36 1999
@@ -584,7 +584,7 @@
                 for (pn = jobtab[jn->other].procs; pn; pn = pn->next)
                     kill(pn->pid, sig);
  
-                for (pn = jn->procs; pn; pn = pn->next)
+                for (pn = jn->procs; pn->next; pn = pn->next)
                     err = kill(pn->pid, sig);
  
                 return err;

--
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de