1 /*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/ioctl.h>
42 #include <sys/param.h>
43 #include <sys/resource.h>
44 #include <sys/time.h>
45 #include <sys/wait.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <paths.h>
49 #include <signal.h>
50 #include <stddef.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53
54 #include "shell.h"
55 #if JOBS
56 #include <termios.h>
57 #undef CEOF /* syntax.h redefines this */
58 #endif
59 #include "redir.h"
60 #include "exec.h"
61 #include "show.h"
62 #include "main.h"
63 #include "parser.h"
64 #include "nodes.h"
65 #include "jobs.h"
66 #include "options.h"
67 #include "trap.h"
68 #include "syntax.h"
69 #include "input.h"
70 #include "output.h"
71 #include "memalloc.h"
72 #include "error.h"
73 #include "mystring.h"
74 #include "var.h"
75 #include "builtins.h"
76
77
78 static struct job *jobtab; /* array of jobs */
79 static int njobs; /* size of array */
80 static pid_t backgndpid = -1; /* pid of last background process */
81 static struct job *bgjob = NULL; /* last background process */
82 #if JOBS
83 static struct job *jobmru; /* most recently used job list */
84 static pid_t initialpgrp; /* pgrp of shell on invocation */
85 #endif
86 static int ttyfd = -1;
87
88 /* mode flags for dowait */
89 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */
90 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signal */
91 #define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */
92
93 #if JOBS
94 static void restartjob(struct job *);
95 #endif
96 static void freejob(struct job *);
97 static int waitcmdloop(struct job *);
98 static struct job *getjob_nonotfound(const char *);
99 static struct job *getjob(const char *);
100 pid_t killjob(const char *, int);
101 static pid_t dowait(int, struct job *);
102 static void checkzombies(void);
103 static void cmdtxt(union node *);
104 static void cmdputs(const char *);
105 #if JOBS
106 static void setcurjob(struct job *);
107 static void deljob(struct job *);
108 static struct job *getcurjob(struct job *);
109 #endif
110 static void printjobcmd(struct job *);
111 static void showjob(struct job *, int);
112
113
114 /*
115 * Turn job control on and off.
116 */
117
118 static int jobctl;
119
120 #if JOBS
121 static void
jobctl_notty(void)122 jobctl_notty(void)
123 {
124 if (ttyfd >= 0) {
125 close(ttyfd);
126 ttyfd = -1;
127 }
128 if (!iflag) {
129 setsignal(SIGTSTP);
130 setsignal(SIGTTOU);
131 setsignal(SIGTTIN);
132 jobctl = 1;
133 return;
134 }
135 out2fmt_flush("sh: can't access tty; job control turned off\n");
136 mflag = 0;
137 }
138
139 void
setjobctl(int on)140 setjobctl(int on)
141 {
142 int i;
143
144 if (on == jobctl || rootshell == 0)
145 return;
146 if (on) {
147 if (ttyfd != -1)
148 close(ttyfd);
149 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) {
150 i = 0;
151 while (i <= 2 && !isatty(i))
152 i++;
153 if (i > 2 ||
154 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) {
155 jobctl_notty();
156 return;
157 }
158 }
159 if (ttyfd < 10) {
160 /*
161 * Keep our TTY file descriptor out of the way of
162 * the user's redirections.
163 */
164 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) {
165 jobctl_notty();
166 return;
167 }
168 close(ttyfd);
169 ttyfd = i;
170 }
171 do { /* while we are in the background */
172 initialpgrp = tcgetpgrp(ttyfd);
173 if (initialpgrp < 0) {
174 jobctl_notty();
175 return;
176 }
177 if (initialpgrp != getpgrp()) {
178 if (!iflag) {
179 initialpgrp = -1;
180 jobctl_notty();
181 return;
182 }
183 kill(0, SIGTTIN);
184 continue;
185 }
186 } while (0);
187 setsignal(SIGTSTP);
188 setsignal(SIGTTOU);
189 setsignal(SIGTTIN);
190 setpgid(0, rootpid);
191 tcsetpgrp(ttyfd, rootpid);
192 } else { /* turning job control off */
193 setpgid(0, initialpgrp);
194 if (ttyfd >= 0) {
195 tcsetpgrp(ttyfd, initialpgrp);
196 close(ttyfd);
197 ttyfd = -1;
198 }
199 setsignal(SIGTSTP);
200 setsignal(SIGTTOU);
201 setsignal(SIGTTIN);
202 }
203 jobctl = on;
204 }
205 #endif
206
207
208 #if JOBS
209 int
fgcmd(int argc __unused,char ** argv __unused)210 fgcmd(int argc __unused, char **argv __unused)
211 {
212 struct job *jp;
213 pid_t pgrp;
214 int status;
215
216 nextopt("");
217 jp = getjob(*argptr);
218 if (jp->jobctl == 0)
219 error("job not created under job control");
220 printjobcmd(jp);
221 flushout(&output);
222 pgrp = jp->ps[0].pid;
223 if (ttyfd >= 0)
224 tcsetpgrp(ttyfd, pgrp);
225 restartjob(jp);
226 jp->foreground = 1;
227 INTOFF;
228 status = waitforjob(jp, (int *)NULL);
229 INTON;
230 return status;
231 }
232
233
234 int
bgcmd(int argc __unused,char ** argv __unused)235 bgcmd(int argc __unused, char **argv __unused)
236 {
237 struct job *jp;
238
239 nextopt("");
240 do {
241 jp = getjob(*argptr);
242 if (jp->jobctl == 0)
243 error("job not created under job control");
244 if (jp->state == JOBDONE)
245 continue;
246 restartjob(jp);
247 jp->foreground = 0;
248 out1fmt("[%td] ", jp - jobtab + 1);
249 printjobcmd(jp);
250 } while (*argptr != NULL && *++argptr != NULL);
251 return 0;
252 }
253
254
255 static void
restartjob(struct job * jp)256 restartjob(struct job *jp)
257 {
258 struct procstat *ps;
259 int i;
260
261 if (jp->state == JOBDONE)
262 return;
263 setcurjob(jp);
264 INTOFF;
265 kill(-jp->ps[0].pid, SIGCONT);
266 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
267 if (WIFSTOPPED(ps->status)) {
268 ps->status = -1;
269 jp->state = 0;
270 }
271 }
272 INTON;
273 }
274 #endif
275
276
277 int
jobscmd(int argc __unused,char * argv[]__unused)278 jobscmd(int argc __unused, char *argv[] __unused)
279 {
280 char *id;
281 int ch, mode;
282
283 mode = SHOWJOBS_DEFAULT;
284 while ((ch = nextopt("lps")) != '\0') {
285 switch (ch) {
286 case 'l':
287 mode = SHOWJOBS_VERBOSE;
288 break;
289 case 'p':
290 mode = SHOWJOBS_PGIDS;
291 break;
292 case 's':
293 mode = SHOWJOBS_PIDS;
294 break;
295 }
296 }
297
298 if (*argptr == NULL)
299 showjobs(0, mode);
300 else
301 while ((id = *argptr++) != NULL)
302 showjob(getjob(id), mode);
303
304 return (0);
305 }
306
307 static void
printjobcmd(struct job * jp)308 printjobcmd(struct job *jp)
309 {
310 struct procstat *ps;
311 int i;
312
313 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
314 out1str(ps->cmd);
315 if (i > 0)
316 out1str(" | ");
317 }
318 out1c('\n');
319 }
320
321 static void
showjob(struct job * jp,int mode)322 showjob(struct job *jp, int mode)
323 {
324 char s[64];
325 char statestr[64];
326 const char *sigstr;
327 struct procstat *ps;
328 struct job *j;
329 int col, curr, i, jobno, prev, procno;
330 char c;
331
332 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs;
333 jobno = jp - jobtab + 1;
334 curr = prev = 0;
335 #if JOBS
336 if ((j = getcurjob(NULL)) != NULL) {
337 curr = j - jobtab + 1;
338 if ((j = getcurjob(j)) != NULL)
339 prev = j - jobtab + 1;
340 }
341 #endif
342 ps = jp->ps + jp->nprocs - 1;
343 if (jp->state == 0) {
344 strcpy(statestr, "Running");
345 #if JOBS
346 } else if (jp->state == JOBSTOPPED) {
347 while (!WIFSTOPPED(ps->status) && ps > jp->ps)
348 ps--;
349 if (WIFSTOPPED(ps->status))
350 i = WSTOPSIG(ps->status);
351 else
352 i = -1;
353 sigstr = strsignal(i);
354 if (sigstr != NULL)
355 strcpy(statestr, sigstr);
356 else
357 strcpy(statestr, "Suspended");
358 #endif
359 } else if (WIFEXITED(ps->status)) {
360 if (WEXITSTATUS(ps->status) == 0)
361 strcpy(statestr, "Done");
362 else
363 fmtstr(statestr, 64, "Done(%d)",
364 WEXITSTATUS(ps->status));
365 } else {
366 i = WTERMSIG(ps->status);
367 sigstr = strsignal(i);
368 if (sigstr != NULL)
369 strcpy(statestr, sigstr);
370 else
371 strcpy(statestr, "Unknown signal");
372 if (WCOREDUMP(ps->status))
373 strcat(statestr, " (core dumped)");
374 }
375
376 for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */
377 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
378 out1fmt("%d\n", (int)ps->pid);
379 continue;
380 }
381 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
382 continue;
383 if (jobno == curr && ps == jp->ps)
384 c = '+';
385 else if (jobno == prev && ps == jp->ps)
386 c = '-';
387 else
388 c = ' ';
389 if (ps == jp->ps)
390 fmtstr(s, 64, "[%d] %c ", jobno, c);
391 else
392 fmtstr(s, 64, " %c ", c);
393 out1str(s);
394 col = strlen(s);
395 if (mode == SHOWJOBS_VERBOSE) {
396 fmtstr(s, 64, "%d ", (int)ps->pid);
397 out1str(s);
398 col += strlen(s);
399 }
400 if (ps == jp->ps) {
401 out1str(statestr);
402 col += strlen(statestr);
403 }
404 do {
405 out1c(' ');
406 col++;
407 } while (col < 30);
408 if (mode == SHOWJOBS_VERBOSE) {
409 out1str(ps->cmd);
410 out1c('\n');
411 } else
412 printjobcmd(jp);
413 }
414 }
415
416 /*
417 * Print a list of jobs. If "change" is nonzero, only print jobs whose
418 * statuses have changed since the last call to showjobs.
419 *
420 * If the shell is interrupted in the process of creating a job, the
421 * result may be a job structure containing zero processes. Such structures
422 * will be freed here.
423 */
424
425 void
showjobs(int change,int mode)426 showjobs(int change, int mode)
427 {
428 int jobno;
429 struct job *jp;
430
431 TRACE(("showjobs(%d) called\n", change));
432 checkzombies();
433 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
434 if (! jp->used)
435 continue;
436 if (jp->nprocs == 0) {
437 freejob(jp);
438 continue;
439 }
440 if (change && ! jp->changed)
441 continue;
442 showjob(jp, mode);
443 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) {
444 jp->changed = 0;
445 /* Hack: discard jobs for which $! has not been
446 * referenced in interactive mode when they terminate.
447 */
448 if (jp->state == JOBDONE && !jp->remembered &&
449 (iflag || jp != bgjob)) {
450 freejob(jp);
451 }
452 }
453 }
454 }
455
456
457 /*
458 * Mark a job structure as unused.
459 */
460
461 static void
freejob(struct job * jp)462 freejob(struct job *jp)
463 {
464 struct procstat *ps;
465 int i;
466
467 INTOFF;
468 if (bgjob == jp)
469 bgjob = NULL;
470 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
471 if (ps->cmd != nullstr)
472 ckfree(ps->cmd);
473 }
474 if (jp->ps != &jp->ps0)
475 ckfree(jp->ps);
476 jp->used = 0;
477 #if JOBS
478 deljob(jp);
479 #endif
480 INTON;
481 }
482
483
484
485 int
waitcmd(int argc __unused,char ** argv __unused)486 waitcmd(int argc __unused, char **argv __unused)
487 {
488 struct job *job;
489 int retval;
490
491 nextopt("");
492 if (*argptr == NULL)
493 return (waitcmdloop(NULL));
494
495 do {
496 job = getjob_nonotfound(*argptr);
497 if (job == NULL)
498 retval = 127;
499 else
500 retval = waitcmdloop(job);
501 argptr++;
502 } while (*argptr != NULL);
503
504 return (retval);
505 }
506
507 static int
waitcmdloop(struct job * job)508 waitcmdloop(struct job *job)
509 {
510 int status, retval, sig;
511 struct job *jp;
512
513 /*
514 * Loop until a process is terminated or stopped, or a SIGINT is
515 * received.
516 */
517
518 do {
519 if (job != NULL) {
520 if (job->state == JOBDONE) {
521 status = job->ps[job->nprocs - 1].status;
522 if (WIFEXITED(status))
523 retval = WEXITSTATUS(status);
524 else
525 retval = WTERMSIG(status) + 128;
526 if (! iflag || ! job->changed)
527 freejob(job);
528 else {
529 job->remembered = 0;
530 if (job == bgjob)
531 bgjob = NULL;
532 }
533 return retval;
534 }
535 } else {
536 for (jp = jobtab ; jp < jobtab + njobs; jp++)
537 if (jp->used && jp->state == JOBDONE) {
538 if (! iflag || ! jp->changed)
539 freejob(jp);
540 else {
541 jp->remembered = 0;
542 if (jp == bgjob)
543 bgjob = NULL;
544 }
545 }
546 for (jp = jobtab ; ; jp++) {
547 if (jp >= jobtab + njobs) { /* no running procs */
548 return 0;
549 }
550 if (jp->used && jp->state == 0)
551 break;
552 }
553 }
554 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1);
555
556 sig = pendingsig_waitcmd;
557 pendingsig_waitcmd = 0;
558 return sig + 128;
559 }
560
561
562
563 int
jobidcmd(int argc __unused,char ** argv __unused)564 jobidcmd(int argc __unused, char **argv __unused)
565 {
566 struct job *jp;
567 int i;
568
569 nextopt("");
570 jp = getjob(*argptr);
571 for (i = 0 ; i < jp->nprocs ; ) {
572 out1fmt("%d", (int)jp->ps[i].pid);
573 out1c(++i < jp->nprocs? ' ' : '\n');
574 }
575 return 0;
576 }
577
578
579
580 /*
581 * Convert a job name to a job structure.
582 */
583
584 static struct job *
getjob_nonotfound(const char * name)585 getjob_nonotfound(const char *name)
586 {
587 int jobno;
588 struct job *found, *jp;
589 size_t namelen;
590 pid_t pid;
591 int i;
592
593 if (name == NULL) {
594 #if JOBS
595 name = "%+";
596 #else
597 error("No current job");
598 #endif
599 }
600 if (name[0] == '%') {
601 if (is_digit(name[1])) {
602 jobno = number(name + 1);
603 if (jobno > 0 && jobno <= njobs
604 && jobtab[jobno - 1].used != 0)
605 return &jobtab[jobno - 1];
606 #if JOBS
607 } else if ((name[1] == '%' || name[1] == '+') &&
608 name[2] == '\0') {
609 if ((jp = getcurjob(NULL)) == NULL)
610 error("No current job");
611 return (jp);
612 } else if (name[1] == '-' && name[2] == '\0') {
613 if ((jp = getcurjob(NULL)) == NULL ||
614 (jp = getcurjob(jp)) == NULL)
615 error("No previous job");
616 return (jp);
617 #endif
618 } else if (name[1] == '?') {
619 found = NULL;
620 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
621 if (jp->used && jp->nprocs > 0
622 && strstr(jp->ps[0].cmd, name + 2) != NULL) {
623 if (found)
624 error("%s: ambiguous", name);
625 found = jp;
626 }
627 }
628 if (found != NULL)
629 return (found);
630 } else {
631 namelen = strlen(name);
632 found = NULL;
633 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
634 if (jp->used && jp->nprocs > 0
635 && strncmp(jp->ps[0].cmd, name + 1,
636 namelen - 1) == 0) {
637 if (found)
638 error("%s: ambiguous", name);
639 found = jp;
640 }
641 }
642 if (found)
643 return found;
644 }
645 } else if (is_number(name)) {
646 pid = (pid_t)number(name);
647 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
648 if (jp->used && jp->nprocs > 0
649 && jp->ps[jp->nprocs - 1].pid == pid)
650 return jp;
651 }
652 }
653 return NULL;
654 }
655
656
657 static struct job *
getjob(const char * name)658 getjob(const char *name)
659 {
660 struct job *jp;
661
662 jp = getjob_nonotfound(name);
663 if (jp == NULL)
664 error("No such job: %s", name);
665 return (jp);
666 }
667
668
669 int
killjob(const char * name,int sig)670 killjob(const char *name, int sig)
671 {
672 struct job *jp;
673 int i, ret;
674
675 jp = getjob(name);
676 if (jp->state == JOBDONE)
677 return 0;
678 if (jp->jobctl)
679 return kill(-jp->ps[0].pid, sig);
680 ret = -1;
681 errno = ESRCH;
682 for (i = 0; i < jp->nprocs; i++)
683 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) {
684 if (kill(jp->ps[i].pid, sig) == 0)
685 ret = 0;
686 } else
687 ret = 0;
688 return ret;
689 }
690
691 /*
692 * Return a new job structure,
693 */
694
695 struct job *
makejob(union node * node __unused,int nprocs)696 makejob(union node *node __unused, int nprocs)
697 {
698 int i;
699 struct job *jp;
700
701 for (i = njobs, jp = jobtab ; ; jp++) {
702 if (--i < 0) {
703 INTOFF;
704 if (njobs == 0) {
705 jobtab = ckmalloc(4 * sizeof jobtab[0]);
706 #if JOBS
707 jobmru = NULL;
708 #endif
709 } else {
710 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
711 memcpy(jp, jobtab, njobs * sizeof jp[0]);
712 #if JOBS
713 /* Relocate `next' pointers and list head */
714 if (jobmru != NULL)
715 jobmru = &jp[jobmru - jobtab];
716 for (i = 0; i < njobs; i++)
717 if (jp[i].next != NULL)
718 jp[i].next = &jp[jp[i].next -
719 jobtab];
720 #endif
721 if (bgjob != NULL)
722 bgjob = &jp[bgjob - jobtab];
723 /* Relocate `ps' pointers */
724 for (i = 0; i < njobs; i++)
725 if (jp[i].ps == &jobtab[i].ps0)
726 jp[i].ps = &jp[i].ps0;
727 ckfree(jobtab);
728 jobtab = jp;
729 }
730 jp = jobtab + njobs;
731 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0)
732 ;
733 INTON;
734 break;
735 }
736 if (jp->used == 0)
737 break;
738 }
739 INTOFF;
740 jp->state = 0;
741 jp->used = 1;
742 jp->changed = 0;
743 jp->nprocs = 0;
744 jp->foreground = 0;
745 jp->remembered = 0;
746 #if JOBS
747 jp->jobctl = jobctl;
748 jp->next = NULL;
749 #endif
750 if (nprocs > 1) {
751 jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
752 } else {
753 jp->ps = &jp->ps0;
754 }
755 INTON;
756 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
757 jp - jobtab + 1));
758 return jp;
759 }
760
761 #if JOBS
762 static void
setcurjob(struct job * cj)763 setcurjob(struct job *cj)
764 {
765 struct job *jp, *prev;
766
767 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
768 if (jp == cj) {
769 if (prev != NULL)
770 prev->next = jp->next;
771 else
772 jobmru = jp->next;
773 jp->next = jobmru;
774 jobmru = cj;
775 return;
776 }
777 }
778 cj->next = jobmru;
779 jobmru = cj;
780 }
781
782 static void
deljob(struct job * j)783 deljob(struct job *j)
784 {
785 struct job *jp, *prev;
786
787 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
788 if (jp == j) {
789 if (prev != NULL)
790 prev->next = jp->next;
791 else
792 jobmru = jp->next;
793 return;
794 }
795 }
796 }
797
798 /*
799 * Return the most recently used job that isn't `nj', and preferably one
800 * that is stopped.
801 */
802 static struct job *
getcurjob(struct job * nj)803 getcurjob(struct job *nj)
804 {
805 struct job *jp;
806
807 /* Try to find a stopped one.. */
808 for (jp = jobmru; jp != NULL; jp = jp->next)
809 if (jp->used && jp != nj && jp->state == JOBSTOPPED)
810 return (jp);
811 /* Otherwise the most recently used job that isn't `nj' */
812 for (jp = jobmru; jp != NULL; jp = jp->next)
813 if (jp->used && jp != nj)
814 return (jp);
815
816 return (NULL);
817 }
818
819 #endif
820
821 /*
822 * Fork of a subshell. If we are doing job control, give the subshell its
823 * own process group. Jp is a job structure that the job is to be added to.
824 * N is the command that will be evaluated by the child. Both jp and n may
825 * be NULL. The mode parameter can be one of the following:
826 * FORK_FG - Fork off a foreground process.
827 * FORK_BG - Fork off a background process.
828 * FORK_NOJOB - Like FORK_FG, but don't give the process its own
829 * process group even if job control is on.
830 *
831 * When job control is turned off, background processes have their standard
832 * input redirected to /dev/null (except for the second and later processes
833 * in a pipeline).
834 */
835
836 pid_t
forkshell(struct job * jp,union node * n,int mode)837 forkshell(struct job *jp, union node *n, int mode)
838 {
839 pid_t pid;
840 pid_t pgrp;
841
842 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
843 mode));
844 INTOFF;
845 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
846 checkzombies();
847 flushall();
848 pid = fork();
849 if (pid == -1) {
850 TRACE(("Fork failed, errno=%d\n", errno));
851 INTON;
852 error("Cannot fork: %s", strerror(errno));
853 }
854 if (pid == 0) {
855 struct job *p;
856 int wasroot;
857 int i;
858
859 TRACE(("Child shell %d\n", (int)getpid()));
860 wasroot = rootshell;
861 rootshell = 0;
862 handler = &main_handler;
863 closescript();
864 INTON;
865 forcelocal = 0;
866 clear_traps();
867 #if JOBS
868 jobctl = 0; /* do job control only in root shell */
869 if (wasroot && mode != FORK_NOJOB && mflag) {
870 if (jp == NULL || jp->nprocs == 0)
871 pgrp = getpid();
872 else
873 pgrp = jp->ps[0].pid;
874 if (setpgid(0, pgrp) == 0 && mode == FORK_FG &&
875 ttyfd >= 0) {
876 /*** this causes superfluous TIOCSPGRPS ***/
877 if (tcsetpgrp(ttyfd, pgrp) < 0)
878 error("tcsetpgrp failed, errno=%d", errno);
879 }
880 setsignal(SIGTSTP);
881 setsignal(SIGTTOU);
882 } else if (mode == FORK_BG) {
883 ignoresig(SIGINT);
884 ignoresig(SIGQUIT);
885 if ((jp == NULL || jp->nprocs == 0) &&
886 ! fd0_redirected_p ()) {
887 close(0);
888 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
889 error("cannot open %s: %s",
890 _PATH_DEVNULL, strerror(errno));
891 }
892 }
893 #else
894 if (mode == FORK_BG) {
895 ignoresig(SIGINT);
896 ignoresig(SIGQUIT);
897 if ((jp == NULL || jp->nprocs == 0) &&
898 ! fd0_redirected_p ()) {
899 close(0);
900 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
901 error("cannot open %s: %s",
902 _PATH_DEVNULL, strerror(errno));
903 }
904 }
905 #endif
906 INTOFF;
907 for (i = njobs, p = jobtab ; --i >= 0 ; p++)
908 if (p->used)
909 freejob(p);
910 INTON;
911 if (wasroot && iflag) {
912 setsignal(SIGINT);
913 setsignal(SIGQUIT);
914 setsignal(SIGTERM);
915 }
916 return pid;
917 }
918 if (rootshell && mode != FORK_NOJOB && mflag) {
919 if (jp == NULL || jp->nprocs == 0)
920 pgrp = pid;
921 else
922 pgrp = jp->ps[0].pid;
923 setpgid(pid, pgrp);
924 }
925 if (mode == FORK_BG) {
926 if (bgjob != NULL && bgjob->state == JOBDONE &&
927 !bgjob->remembered && !iflag)
928 freejob(bgjob);
929 backgndpid = pid; /* set $! */
930 bgjob = jp;
931 }
932 if (jp) {
933 struct procstat *ps = &jp->ps[jp->nprocs++];
934 ps->pid = pid;
935 ps->status = -1;
936 ps->cmd = nullstr;
937 if (iflag && rootshell && n)
938 ps->cmd = commandtext(n);
939 jp->foreground = mode == FORK_FG;
940 #if JOBS
941 setcurjob(jp);
942 #endif
943 }
944 INTON;
945 TRACE(("In parent shell: child = %d\n", (int)pid));
946 return pid;
947 }
948
949
950 pid_t
vforkexecshell(struct job * jp,char ** argv,char ** envp,const char * path,int idx,int pip[2])951 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
952 {
953 pid_t pid;
954 struct jmploc jmploc;
955 struct jmploc *savehandler;
956
957 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
958 (void *)pip));
959 INTOFF;
960 flushall();
961 savehandler = handler;
962 pid = vfork();
963 if (pid == -1) {
964 TRACE(("Vfork failed, errno=%d\n", errno));
965 INTON;
966 error("Cannot fork: %s", strerror(errno));
967 }
968 if (pid == 0) {
969 TRACE(("Child shell %d\n", (int)getpid()));
970 if (setjmp(jmploc.loc))
971 _exit(exception == EXEXEC ? exerrno : 2);
972 if (pip != NULL) {
973 close(pip[0]);
974 if (pip[1] != 1) {
975 dup2(pip[1], 1);
976 close(pip[1]);
977 }
978 }
979 handler = &jmploc;
980 shellexec(argv, envp, path, idx);
981 }
982 handler = savehandler;
983 if (jp) {
984 struct procstat *ps = &jp->ps[jp->nprocs++];
985 ps->pid = pid;
986 ps->status = -1;
987 ps->cmd = nullstr;
988 jp->foreground = 1;
989 #if JOBS
990 setcurjob(jp);
991 #endif
992 }
993 INTON;
994 TRACE(("In parent shell: child = %d\n", (int)pid));
995 return pid;
996 }
997
998
999 /*
1000 * Wait for job to finish.
1001 *
1002 * Under job control we have the problem that while a child process is
1003 * running interrupts generated by the user are sent to the child but not
1004 * to the shell. This means that an infinite loop started by an inter-
1005 * active user may be hard to kill. With job control turned off, an
1006 * interactive user may place an interactive program inside a loop. If
1007 * the interactive program catches interrupts, the user doesn't want
1008 * these interrupts to also abort the loop. The approach we take here
1009 * is to have the shell ignore interrupt signals while waiting for a
1010 * foreground process to terminate, and then send itself an interrupt
1011 * signal if the child process was terminated by an interrupt signal.
1012 * Unfortunately, some programs want to do a bit of cleanup and then
1013 * exit on interrupt; unless these processes terminate themselves by
1014 * sending a signal to themselves (instead of calling exit) they will
1015 * confuse this approach.
1016 */
1017
1018 int
waitforjob(struct job * jp,int * origstatus)1019 waitforjob(struct job *jp, int *origstatus)
1020 {
1021 #if JOBS
1022 int propagate_int = jp->jobctl && jp->foreground;
1023 #endif
1024 int status;
1025 int st;
1026
1027 INTOFF;
1028 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
1029 while (jp->state == 0)
1030 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG |
1031 DOWAIT_SIG_TRAP : 0), jp) == -1)
1032 dotrap();
1033 #if JOBS
1034 if (jp->jobctl) {
1035 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0)
1036 error("tcsetpgrp failed, errno=%d\n", errno);
1037 }
1038 if (jp->state == JOBSTOPPED)
1039 setcurjob(jp);
1040 #endif
1041 status = jp->ps[jp->nprocs - 1].status;
1042 if (origstatus != NULL)
1043 *origstatus = status;
1044 /* convert to 8 bits */
1045 if (WIFEXITED(status))
1046 st = WEXITSTATUS(status);
1047 #if JOBS
1048 else if (WIFSTOPPED(status))
1049 st = WSTOPSIG(status) + 128;
1050 #endif
1051 else
1052 st = WTERMSIG(status) + 128;
1053 if (! JOBS || jp->state == JOBDONE)
1054 freejob(jp);
1055 if (int_pending()) {
1056 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
1057 CLEAR_PENDING_INT;
1058 }
1059 #if JOBS
1060 else if (rootshell && propagate_int &&
1061 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1062 kill(getpid(), SIGINT);
1063 #endif
1064 INTON;
1065 return st;
1066 }
1067
1068
1069 static void
dummy_handler(int sig __unused)1070 dummy_handler(int sig __unused)
1071 {
1072 }
1073
1074 /*
1075 * Wait for a process to terminate.
1076 */
1077
1078 static pid_t
dowait(int mode,struct job * job)1079 dowait(int mode, struct job *job)
1080 {
1081 struct sigaction sa, osa;
1082 sigset_t mask, omask;
1083 pid_t pid;
1084 int status;
1085 struct procstat *sp;
1086 struct job *jp;
1087 struct job *thisjob;
1088 const char *sigstr;
1089 int done;
1090 int stopped;
1091 int sig;
1092 int coredump;
1093 int wflags;
1094 int restore_sigchld;
1095
1096 TRACE(("dowait(%d, %p) called\n", mode, job));
1097 restore_sigchld = 0;
1098 if ((mode & DOWAIT_SIG) != 0) {
1099 sigfillset(&mask);
1100 sigprocmask(SIG_BLOCK, &mask, &omask);
1101 INTOFF;
1102 if (!issigchldtrapped()) {
1103 restore_sigchld = 1;
1104 sa.sa_handler = dummy_handler;
1105 sa.sa_flags = 0;
1106 sigemptyset(&sa.sa_mask);
1107 sigaction(SIGCHLD, &sa, &osa);
1108 }
1109 }
1110 do {
1111 #if JOBS
1112 if (iflag)
1113 wflags = WUNTRACED | WCONTINUED;
1114 else
1115 #endif
1116 wflags = 0;
1117 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
1118 wflags |= WNOHANG;
1119 pid = wait3(&status, wflags, (struct rusage *)NULL);
1120 TRACE(("wait returns %d, status=%d\n", (int)pid, status));
1121 if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
1122 pid = -1;
1123 if (((mode & DOWAIT_SIG_TRAP) != 0 ?
1124 pendingsig : pendingsig_waitcmd) != 0) {
1125 errno = EINTR;
1126 break;
1127 }
1128 sigsuspend(&omask);
1129 if (int_pending())
1130 break;
1131 }
1132 } while (pid == -1 && errno == EINTR);
1133 if (pid == -1 && errno == ECHILD && job != NULL)
1134 job->state = JOBDONE;
1135 if ((mode & DOWAIT_SIG) != 0) {
1136 if (restore_sigchld)
1137 sigaction(SIGCHLD, &osa, NULL);
1138 sigprocmask(SIG_SETMASK, &omask, NULL);
1139 INTON;
1140 }
1141 if (pid <= 0)
1142 return pid;
1143 INTOFF;
1144 thisjob = NULL;
1145 for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1146 if (jp->used && jp->nprocs > 0) {
1147 done = 1;
1148 stopped = 1;
1149 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1150 if (sp->pid == -1)
1151 continue;
1152 if (sp->pid == pid && (sp->status == -1 ||
1153 WIFSTOPPED(sp->status))) {
1154 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
1155 (int)pid, sp->status,
1156 status));
1157 if (WIFCONTINUED(status)) {
1158 sp->status = -1;
1159 jp->state = 0;
1160 } else
1161 sp->status = status;
1162 thisjob = jp;
1163 }
1164 if (sp->status == -1)
1165 stopped = 0;
1166 else if (WIFSTOPPED(sp->status))
1167 done = 0;
1168 }
1169 if (stopped) { /* stopped or done */
1170 int state = done? JOBDONE : JOBSTOPPED;
1171 if (jp->state != state) {
1172 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1173 jp->state = state;
1174 if (jp != job) {
1175 if (done && !jp->remembered &&
1176 !iflag && jp != bgjob)
1177 freejob(jp);
1178 #if JOBS
1179 else if (done)
1180 deljob(jp);
1181 #endif
1182 }
1183 }
1184 }
1185 }
1186 }
1187 INTON;
1188 if (!thisjob || thisjob->state == 0)
1189 ;
1190 else if ((!rootshell || !iflag || thisjob == job) &&
1191 thisjob->foreground && thisjob->state != JOBSTOPPED) {
1192 sig = 0;
1193 coredump = 0;
1194 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
1195 if (WIFSIGNALED(sp->status)) {
1196 sig = WTERMSIG(sp->status);
1197 coredump = WCOREDUMP(sp->status);
1198 }
1199 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
1200 sigstr = strsignal(sig);
1201 if (sigstr != NULL)
1202 out2str(sigstr);
1203 else
1204 out2str("Unknown signal");
1205 if (coredump)
1206 out2str(" (core dumped)");
1207 out2c('\n');
1208 flushout(out2);
1209 }
1210 } else {
1211 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
1212 thisjob->changed = 1;
1213 }
1214 return pid;
1215 }
1216
1217
1218
1219 /*
1220 * return 1 if there are stopped jobs, otherwise 0
1221 */
1222 int job_warning = 0;
1223 int
stoppedjobs(void)1224 stoppedjobs(void)
1225 {
1226 int jobno;
1227 struct job *jp;
1228
1229 if (job_warning)
1230 return (0);
1231 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1232 if (jp->used == 0)
1233 continue;
1234 if (jp->state == JOBSTOPPED) {
1235 out2fmt_flush("You have stopped jobs.\n");
1236 job_warning = 2;
1237 return (1);
1238 }
1239 }
1240
1241 return (0);
1242 }
1243
1244
1245 static void
checkzombies(void)1246 checkzombies(void)
1247 {
1248 while (njobs > 0 && dowait(0, NULL) > 0)
1249 ;
1250 }
1251
1252
1253 int
backgndpidset(void)1254 backgndpidset(void)
1255 {
1256 return backgndpid != -1;
1257 }
1258
1259
1260 pid_t
backgndpidval(void)1261 backgndpidval(void)
1262 {
1263 if (bgjob != NULL && !forcelocal)
1264 bgjob->remembered = 1;
1265 return backgndpid;
1266 }
1267
1268 /*
1269 * Return a string identifying a command (to be printed by the
1270 * jobs command.
1271 */
1272
1273 static char *cmdnextc;
1274 static int cmdnleft;
1275 #define MAXCMDTEXT 200
1276
1277 char *
commandtext(union node * n)1278 commandtext(union node *n)
1279 {
1280 char *name;
1281
1282 cmdnextc = name = ckmalloc(MAXCMDTEXT);
1283 cmdnleft = MAXCMDTEXT - 4;
1284 cmdtxt(n);
1285 *cmdnextc = '\0';
1286 return name;
1287 }
1288
1289
1290 static void
cmdtxtdogroup(union node * n)1291 cmdtxtdogroup(union node *n)
1292 {
1293 cmdputs("; do ");
1294 cmdtxt(n);
1295 cmdputs("; done");
1296 }
1297
1298
1299 static void
cmdtxtredir(union node * n,const char * op,int deffd)1300 cmdtxtredir(union node *n, const char *op, int deffd)
1301 {
1302 char s[2];
1303
1304 if (n->nfile.fd != deffd) {
1305 s[0] = n->nfile.fd + '0';
1306 s[1] = '\0';
1307 cmdputs(s);
1308 }
1309 cmdputs(op);
1310 if (n->type == NTOFD || n->type == NFROMFD) {
1311 if (n->ndup.dupfd >= 0)
1312 s[0] = n->ndup.dupfd + '0';
1313 else
1314 s[0] = '-';
1315 s[1] = '\0';
1316 cmdputs(s);
1317 } else {
1318 cmdtxt(n->nfile.fname);
1319 }
1320 }
1321
1322
1323 static void
cmdtxt(union node * n)1324 cmdtxt(union node *n)
1325 {
1326 union node *np;
1327 struct nodelist *lp;
1328
1329 if (n == NULL)
1330 return;
1331 switch (n->type) {
1332 case NSEMI:
1333 cmdtxt(n->nbinary.ch1);
1334 cmdputs("; ");
1335 cmdtxt(n->nbinary.ch2);
1336 break;
1337 case NAND:
1338 cmdtxt(n->nbinary.ch1);
1339 cmdputs(" && ");
1340 cmdtxt(n->nbinary.ch2);
1341 break;
1342 case NOR:
1343 cmdtxt(n->nbinary.ch1);
1344 cmdputs(" || ");
1345 cmdtxt(n->nbinary.ch2);
1346 break;
1347 case NPIPE:
1348 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1349 cmdtxt(lp->n);
1350 if (lp->next)
1351 cmdputs(" | ");
1352 }
1353 break;
1354 case NSUBSHELL:
1355 cmdputs("(");
1356 cmdtxt(n->nredir.n);
1357 cmdputs(")");
1358 break;
1359 case NREDIR:
1360 case NBACKGND:
1361 cmdtxt(n->nredir.n);
1362 break;
1363 case NIF:
1364 cmdputs("if ");
1365 cmdtxt(n->nif.test);
1366 cmdputs("; then ");
1367 cmdtxt(n->nif.ifpart);
1368 cmdputs("...");
1369 break;
1370 case NWHILE:
1371 cmdputs("while ");
1372 cmdtxt(n->nbinary.ch1);
1373 cmdtxtdogroup(n->nbinary.ch2);
1374 break;
1375 case NUNTIL:
1376 cmdputs("until ");
1377 cmdtxt(n->nbinary.ch1);
1378 cmdtxtdogroup(n->nbinary.ch2);
1379 break;
1380 case NFOR:
1381 cmdputs("for ");
1382 cmdputs(n->nfor.var);
1383 cmdputs(" in ...");
1384 break;
1385 case NCASE:
1386 cmdputs("case ");
1387 cmdputs(n->ncase.expr->narg.text);
1388 cmdputs(" in ...");
1389 break;
1390 case NDEFUN:
1391 cmdputs(n->narg.text);
1392 cmdputs("() ...");
1393 break;
1394 case NNOT:
1395 cmdputs("! ");
1396 cmdtxt(n->nnot.com);
1397 break;
1398 case NCMD:
1399 for (np = n->ncmd.args ; np ; np = np->narg.next) {
1400 cmdtxt(np);
1401 if (np->narg.next)
1402 cmdputs(" ");
1403 }
1404 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
1405 cmdputs(" ");
1406 cmdtxt(np);
1407 }
1408 break;
1409 case NARG:
1410 cmdputs(n->narg.text);
1411 break;
1412 case NTO:
1413 cmdtxtredir(n, ">", 1);
1414 break;
1415 case NAPPEND:
1416 cmdtxtredir(n, ">>", 1);
1417 break;
1418 case NTOFD:
1419 cmdtxtredir(n, ">&", 1);
1420 break;
1421 case NCLOBBER:
1422 cmdtxtredir(n, ">|", 1);
1423 break;
1424 case NFROM:
1425 cmdtxtredir(n, "<", 0);
1426 break;
1427 case NFROMTO:
1428 cmdtxtredir(n, "<>", 0);
1429 break;
1430 case NFROMFD:
1431 cmdtxtredir(n, "<&", 0);
1432 break;
1433 case NHERE:
1434 case NXHERE:
1435 cmdputs("<<...");
1436 break;
1437 default:
1438 cmdputs("???");
1439 break;
1440 }
1441 }
1442
1443
1444
1445 static void
cmdputs(const char * s)1446 cmdputs(const char *s)
1447 {
1448 const char *p;
1449 char *q;
1450 char c;
1451 int subtype = 0;
1452
1453 if (cmdnleft <= 0)
1454 return;
1455 p = s;
1456 q = cmdnextc;
1457 while ((c = *p++) != '\0') {
1458 if (c == CTLESC)
1459 *q++ = *p++;
1460 else if (c == CTLVAR) {
1461 *q++ = '$';
1462 if (--cmdnleft > 0)
1463 *q++ = '{';
1464 subtype = *p++;
1465 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
1466 *q++ = '#';
1467 } else if (c == '=' && subtype != 0) {
1468 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
1469 if (*q)
1470 q++;
1471 else
1472 cmdnleft++;
1473 if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
1474 (subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
1475 --cmdnleft > 0)
1476 *q = q[-1], q++;
1477 subtype = 0;
1478 } else if (c == CTLENDVAR) {
1479 *q++ = '}';
1480 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
1481 cmdnleft -= 5;
1482 if (cmdnleft > 0) {
1483 *q++ = '$';
1484 *q++ = '(';
1485 *q++ = '.';
1486 *q++ = '.';
1487 *q++ = '.';
1488 *q++ = ')';
1489 }
1490 } else if (c == CTLARI) {
1491 cmdnleft -= 2;
1492 if (cmdnleft > 0) {
1493 *q++ = '$';
1494 *q++ = '(';
1495 *q++ = '(';
1496 }
1497 p++;
1498 } else if (c == CTLENDARI) {
1499 if (--cmdnleft > 0) {
1500 *q++ = ')';
1501 *q++ = ')';
1502 }
1503 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
1504 cmdnleft++; /* ignore */
1505 else
1506 *q++ = c;
1507 if (--cmdnleft <= 0) {
1508 *q++ = '.';
1509 *q++ = '.';
1510 *q++ = '.';
1511 break;
1512 }
1513 }
1514 cmdnextc = q;
1515 }
1516