Re: zsh: Strange feature with 'jobs' commmand

[Peter Stephenson <pws@xxxxxxx>]

Oliver Kiddle wrote:
> I was puzzling as to why this allows jobs|less to work but not
> (jobs) or cat <(jobs) when I realised that if I have two background
> jobs, (jobs) will print the second job only. So perhaps this isn't quite
> right yet? I don't really understand it though so I'm not sure why.
> Hopefully something trivial because it'd be nice to have this working.
> 
> And, a minor point is that the clone module didn't compile - just the
> missing new parameter to clearjobtab.

also i screwed up counting the number of jobs in the table to copy.

bart was right.

mark 2.  i almost sent the code that configures the radio for the
latest version of our chip instead, maybe you would have liked that better.

also tries, fairly naively but apparently successfully, to preserve `+'
and `-' markings.

i think we could safely abort bin_fg earlier in other cases where there
is no job control.

Index: Src/exec.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/exec.c,v
retrieving revision 1.41
diff -u -r1.41 exec.c
--- Src/exec.c	6 May 2002 14:46:11 -0000	1.41
+++ Src/exec.c	30 May 2002 17:20:28 -0000
@@ -2507,13 +2507,13 @@
 static void
 entersubsh(int how, int cl, int fake)
 {
-    int sig;
+    int sig, monitor;
 
     if (cl != 2)
 	for (sig = 0; sig < VSIGCOUNT; sig++)
 	    if (!(sigtrapped[sig] & ZSIG_FUNC))
 		unsettrap(sig);
-    if (unset(MONITOR)) {
+    if (!(monitor = isset(MONITOR))) {
 	if (how & Z_ASYNC) {
 	    settrap(SIGINT, NULL);
 	    settrap(SIGQUIT, NULL);
@@ -2569,7 +2569,7 @@
     opts[MONITOR] = opts[USEZLE] = 0;
     zleactive = 0;
     if (cl)
-	clearjobtab();
+	clearjobtab(monitor);
     times(&shtms);
     forklevel = locallevel;
 }
Index: Src/jobs.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/jobs.c,v
retrieving revision 1.15
diff -u -r1.15 jobs.c
--- Src/jobs.c	21 Dec 2001 16:33:39 -0000	1.15
+++ Src/jobs.c	30 May 2002 17:20:28 -0000
@@ -55,6 +55,12 @@
 /**/
 mod_export struct job jobtab[MAXJOB];
 
+/* If we have entered a subshell, the original shell's job table. */
+static struct job *oldjobtab;
+
+/* The size of that. */
+static int oldmaxjob;
+
 /* shell timings */
  
 /**/
@@ -612,13 +618,18 @@
 printjob(Job jn, int lng, int synch)
 {
     Process pn;
-    int job = jn - jobtab, len = 9, sig, sflag = 0, llen;
+    int job, len = 9, sig, sflag = 0, llen;
     int conted = 0, lineleng = columns, skip = 0, doputnl = 0;
     FILE *fout = (synch == 2) ? stdout : shout;
 
     if (jn->stat & STAT_NOPRINT)
 	return;
 
+    if (jn < jobtab || jn >= jobtab + MAXJOB)
+	job = jn - oldjobtab;
+    else
+	job = jn - jobtab;
+
     if (lng < 0) {
 	conted = 1;
 	lng = 0;
@@ -655,11 +666,14 @@
 	}
     }
 
-/* print if necessary */
+/* print if necessary: ignore option state on explicit call to `jobs'. */
 
-    if (interact && jobbing && ((jn->stat & STAT_STOPPED) || sflag ||
-				job != thisjob)) {
+    if (synch == 2 || 
+	(interact && jobbing &&
+	 ((jn->stat & STAT_STOPPED) || sflag || job != thisjob))) {
 	int len2, fline = 1;
+	/* use special format for current job, except in `jobs' */
+	int thisfmt = job == thisjob && synch != 2;
 	Process qn;
 
 	if (!synch)
@@ -667,7 +681,7 @@
 	if (doputnl && !synch)
 	    putc('\n', fout);
 	for (pn = jn->procs; pn;) {
-	    len2 = ((job == thisjob) ? 5 : 10) + len;	/* 2 spaces */
+	    len2 = (thisfmt ? 5 : 10) + len;	/* 2 spaces */
 	    if (lng & 3)
 		qn = pn->next;
 	    else
@@ -678,10 +692,10 @@
 			break;
 		    len2 += strlen(qn->text) + 2;
 		}
-	    if (job != thisjob) {
+	    if (!thisfmt) {
 		if (fline)
 		    fprintf(fout, "[%ld]  %c ",
-			    (long)(jn - jobtab),
+			    (long)job,
 			    (job == curjob) ? '+'
 			    : (job == prevjob) ? '-' : ' ');
 		else
@@ -956,13 +970,32 @@
 
 /**/
 mod_export void
-clearjobtab(void)
+clearjobtab(int monitor)
 {
     int i;
 
-    for (i = 1; i < MAXJOB; i++)
-	if (jobtab[i].ty)
+    for (i = 1; i < MAXJOB; i++) {
+	if (jobtab[i].ty) {
 	    zfree(jobtab[i].ty, sizeof(struct ttyinfo));
+	    jobtab[i].ty = NULL;
+	}
+	if (monitor) {
+	    /*
+	     * See if there is a jobtable worth saving.
+	     * We never free the saved version; it only happens
+	     * once for each subshell of a shell with job control,
+	     * so doesn't create a leak.
+	     */
+	    if (jobtab[i].stat)
+		oldmaxjob = i+1;
+	}
+    }
+
+    if (monitor && oldmaxjob) {
+	int sz = oldmaxjob * sizeof(struct job);
+	oldjobtab = (struct job *)zalloc(sz);
+	memcpy(oldjobtab, jobtab, sz);
+    }
 
     memset(jobtab, 0, sizeof(jobtab)); /* zero out table */
 }
@@ -1253,7 +1286,8 @@
     if (unset(NOTIFY))
 	scanjobs();
 
-    setcurjob();
+    if (func != BIN_JOBS || isset(MONITOR) || !oldmaxjob)
+	setcurjob();
 
     if (func == BIN_JOBS)
         /* If you immediately type "exit" after "jobs", this      *
@@ -1274,13 +1308,24 @@
 	    firstjob = curjob;
 	} else if (func == BIN_JOBS) {
 	    /* List jobs. */
-	    for (job = 0; job != MAXJOB; job++)
-		if (job != thisjob && jobtab[job].stat) {
+	    struct job *jobptr;
+	    int maxjob, ignorejob;
+	    if (unset(MONITOR) && oldmaxjob) {
+		jobptr = oldjobtab;
+		maxjob = oldmaxjob;
+		ignorejob = 0;
+	    } else {
+		jobptr = jobtab;
+		maxjob = MAXJOB;
+		ignorejob = thisjob;
+	    }
+	    for (job = 0; job != maxjob; job++, jobptr++)
+		if (job != ignorejob && jobptr->stat) {
 		    if ((!ops['r'] && !ops['s']) ||
 			(ops['r'] && ops['s']) ||
-			(ops['r'] && !(jobtab[job].stat & STAT_STOPPED)) ||
-			(ops['s'] && jobtab[job].stat & STAT_STOPPED))
-			printjob(job + jobtab, lng, 2);
+			(ops['r'] && !(jobptr->stat & STAT_STOPPED)) ||
+			(ops['s'] && jobptr->stat & STAT_STOPPED))
+			printjob(jobptr, lng, 2);
 		}
 	    unqueue_signals();
 	    return 0;
Index: Src/Modules/clone.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Modules/clone.c,v
retrieving revision 1.1.1.7
diff -u -r1.1.1.7 clone.c
--- Src/Modules/clone.c	16 Dec 1999 14:26:36 -0000	1.1.1.7
+++ Src/Modules/clone.c	30 May 2002 17:20:28 -0000
@@ -53,7 +53,7 @@
     }
     pid = fork();
     if (!pid) {
-	clearjobtab();
+	clearjobtab(0);
 	ppid = getppid();
 	mypid = getpid();
 #ifdef HAVE_SETSID

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 392070


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