1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/ioctl.h>
36#include <sys/param.h>
37#include <sys/resource.h>
38#include <sys/time.h>
39#include <sys/wait.h>
40#include <errno.h>
41#include <fcntl.h>
42#include <paths.h>
43#include <signal.h>
44#include <stddef.h>
45#include <stdlib.h>
46#include <unistd.h>
47
48#include "shell.h"
49#if JOBS
50#include <termios.h>
51#undef CEOF /* syntax.h redefines this */
52#endif
53#include "redir.h"
54#include "exec.h"
55#include "show.h"
56#include "main.h"
57#include "parser.h"
58#include "nodes.h"
59#include "jobs.h"
60#include "options.h"
61#include "trap.h"
62#include "syntax.h"
63#include "input.h"
64#include "output.h"
65#include "memalloc.h"
66#include "error.h"
67#include "mystring.h"
68#include "var.h"
69#include "builtins.h"
70#include "eval.h"
71
72
73/*
74 * A job structure contains information about a job. A job is either a
75 * single process or a set of processes contained in a pipeline. In the
76 * latter case, pidlist will be non-NULL, and will point to a -1 terminated
77 * array of pids.
78 */
79
80struct procstat {
81 pid_t pid; /* process id */
82 int status; /* status flags (defined above) */
83 char *cmd; /* text of command being run */
84};
85
86
87/* states */
88#define JOBSTOPPED 1 /* all procs are stopped */
89#define JOBDONE 2 /* all procs are completed */
90
91
92struct job {
93 struct procstat ps0; /* status of process */
94 struct procstat *ps; /* status or processes when more than one */
95 short nprocs; /* number of processes */
96 pid_t pgrp; /* process group of this job */
97 char state; /* true if job is finished */
98 char used; /* true if this entry is in use */
99 char changed; /* true if status has changed */
100 char foreground; /* true if running in the foreground */
101 char remembered; /* true if $! referenced */
102 char pipefail; /* pass any non-zero status */
103#if JOBS
104 char jobctl; /* job running under job control */
105 struct job *next; /* job used after this one */
106#endif
107};
108
109
110static struct job *jobtab; /* array of jobs */
111static int njobs; /* size of array */
112static pid_t backgndpid = -1; /* pid of last background process */
113static struct job *bgjob = NULL; /* last background process */
114#if JOBS
115static struct job *jobmru; /* most recently used job list */
116static pid_t initialpgrp; /* pgrp of shell on invocation */
117#endif
118static int ttyfd = -1;
119
120/* mode flags for dowait */
121#define DOWAIT_BLOCK 0x1 /* wait until a child exits */
122#define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signal */
123#define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */
124
125#if JOBS
126static void restartjob(struct job *);
127#endif
128static void freejob(struct job *);
129static int waitcmdloop(struct job *);
130static struct job *getjob_nonotfound(const char *);
131static struct job *getjob(const char *);
132pid_t killjob(const char *, int);
133static pid_t dowait(int, struct job *);
134static void checkzombies(void);
135static void cmdtxt(union node *);
136static void cmdputs(const char *);
137#if JOBS
138static void setcurjob(struct job *);
139static void deljob(struct job *);
140static struct job *getcurjob(struct job *);
141#endif
142static int getjobstatus(const struct job *);
143static void printjobcmd(struct job *);
144static void showjob(struct job *, int);
145
146
147/*
148 * Turn job control on and off.
149 */
150
151static int jobctl;
152
153#if JOBS
154static void
155jobctl_notty(void)
156{
157 if (ttyfd >= 0) {
158 close(ttyfd);
159 ttyfd = -1;
160 }
161 if (!iflag) {
162 setsignal(SIGTSTP);
163 setsignal(SIGTTOU);
164 setsignal(SIGTTIN);
165 jobctl = 1;
166 return;
167 }
168 out2fmt_flush("sh: can't access tty; job control turned off\n");
169 mflag = 0;
170}
171
172void
173setjobctl(int on)
174{
175 int i;
176
177 if (on == jobctl || rootshell == 0)
178 return;
179 if (on) {
180 if (ttyfd != -1)
181 close(ttyfd);
182 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) {
183 i = 0;
184 while (i <= 2 && !isatty(i))
185 i++;
186 if (i > 2 ||
187 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) {
188 jobctl_notty();
189 return;
190 }
191 }
192 if (ttyfd < 10) {
193 /*
194 * Keep our TTY file descriptor out of the way of
195 * the user's redirections.
196 */
197 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) {
198 jobctl_notty();
199 return;
200 }
201 close(ttyfd);
202 ttyfd = i;
203 }
204 do { /* while we are in the background */
205 initialpgrp = tcgetpgrp(ttyfd);
206 if (initialpgrp < 0) {
207 jobctl_notty();
208 return;
209 }
210 if (initialpgrp != getpgrp()) {
211 if (!iflag) {
212 initialpgrp = -1;
213 jobctl_notty();
214 return;
215 }
216 kill(0, SIGTTIN);
217 continue;
218 }
219 } while (0);
220 setsignal(SIGTSTP);
221 setsignal(SIGTTOU);
222 setsignal(SIGTTIN);
223 setpgid(0, rootpid);
224 tcsetpgrp(ttyfd, rootpid);
225 } else { /* turning job control off */
226 setpgid(0, initialpgrp);
227 if (ttyfd >= 0) {
228 tcsetpgrp(ttyfd, initialpgrp);
229 close(ttyfd);
230 ttyfd = -1;
231 }
232 setsignal(SIGTSTP);
233 setsignal(SIGTTOU);
234 setsignal(SIGTTIN);
235 }
236 jobctl = on;
237}
238#endif
239
240
241#if JOBS
242int
243fgcmd(int argc __unused, char **argv __unused)
244{
245 struct job *jp;
246 pid_t pgrp;
247 int status;
248
249 nextopt("");
250 jp = getjob(*argptr);
251 if (jp->jobctl == 0)
252 error("job not created under job control");
253 printjobcmd(jp);
254 flushout(&output);
255 pgrp = jp->ps[0].pid;
256 if (ttyfd >= 0)
257 tcsetpgrp(ttyfd, pgrp);
258 restartjob(jp);
259 jp->foreground = 1;
260 INTOFF;
261 status = waitforjob(jp, (int *)NULL);
262 INTON;
263 return status;
264}
265
266
267int
268bgcmd(int argc __unused, char **argv __unused)
269{
270 struct job *jp;
271
272 nextopt("");
273 do {
274 jp = getjob(*argptr);
275 if (jp->jobctl == 0)
276 error("job not created under job control");
277 if (jp->state == JOBDONE)
278 continue;
279 restartjob(jp);
280 jp->foreground = 0;
281 out1fmt("[%td] ", jp - jobtab + 1);
282 printjobcmd(jp);
283 } while (*argptr != NULL && *++argptr != NULL);
284 return 0;
285}
286
287
288static void
289restartjob(struct job *jp)
290{
291 struct procstat *ps;
292 int i;
293
294 if (jp->state == JOBDONE)
295 return;
296 setcurjob(jp);
297 INTOFF;
298 kill(-jp->ps[0].pid, SIGCONT);
299 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
300 if (WIFSTOPPED(ps->status)) {
301 ps->status = -1;
302 jp->state = 0;
303 }
304 }
305 INTON;
306}
307#endif
308
309
310int
311jobscmd(int argc __unused, char *argv[] __unused)
312{
313 char *id;
314 int ch, mode;
315
316 mode = SHOWJOBS_DEFAULT;
317 while ((ch = nextopt("lps")) != '\0') {
318 switch (ch) {
319 case 'l':
320 mode = SHOWJOBS_VERBOSE;
321 break;
322 case 'p':
323 mode = SHOWJOBS_PGIDS;
324 break;
325 case 's':
326 mode = SHOWJOBS_PIDS;
327 break;
328 }
329 }
330
331 if (*argptr == NULL)
332 showjobs(0, mode);
333 else
334 while ((id = *argptr++) != NULL)
335 showjob(getjob(id), mode);
336
337 return (0);
338}
339
340static int getjobstatus(const struct job *jp)
341{
342 int i, status;
343
344 if (!jp->pipefail)
345 return (jp->ps[jp->nprocs - 1].status);
346 for (i = jp->nprocs - 1; i >= 0; i--) {
347 status = jp->ps[i].status;
348 if (status != 0)
349 return (status);
350 }
351 return (0);
352}
353
354static void
355printjobcmd(struct job *jp)
356{
357 struct procstat *ps;
358 int i;
359
360 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
361 out1str(ps->cmd);
362 if (i > 0)
363 out1str(" | ");
364 }
365 out1c('\n');
366}
367
368static void
369showjob(struct job *jp, int mode)
370{
371 char s[64];
372 char statebuf[16];
373 const char *statestr, *coredump;
374 struct procstat *ps;
375 struct job *j;
376 int col, curr, i, jobno, prev, procno, status;
377 char c;
378
379 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs;
380 jobno = jp - jobtab + 1;
381 curr = prev = 0;
382#if JOBS
383 if ((j = getcurjob(NULL)) != NULL) {
384 curr = j - jobtab + 1;
385 if ((j = getcurjob(j)) != NULL)
386 prev = j - jobtab + 1;
387 }
388#endif
389 coredump = "";
390 status = getjobstatus(jp);
391 if (jp->state == 0) {
392 statestr = "Running";
393#if JOBS
394 } else if (jp->state == JOBSTOPPED) {
395 ps = jp->ps + jp->nprocs - 1;
396 while (!WIFSTOPPED(ps->status) && ps > jp->ps)
397 ps--;
398 if (WIFSTOPPED(ps->status))
399 i = WSTOPSIG(ps->status);
400 else
401 i = -1;
402 statestr = strsignal(i);
403 if (statestr == NULL)
404 statestr = "Suspended";
405#endif
406 } else if (WIFEXITED(status)) {
407 if (WEXITSTATUS(status) == 0)
408 statestr = "Done";
409 else {
410 fmtstr(statebuf, sizeof(statebuf), "Done(%d)",
411 WEXITSTATUS(status));
412 statestr = statebuf;
413 }
414 } else {
415 i = WTERMSIG(status);
416 statestr = strsignal(i);
417 if (statestr == NULL)
418 statestr = "Unknown signal";
419 if (WCOREDUMP(status))
420 coredump = " (core dumped)";
421 }
422
423 for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */
424 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
425 out1fmt("%d\n", (int)ps->pid);
426 continue;
427 }
428 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
429 continue;
430 if (jobno == curr && ps == jp->ps)
431 c = '+';
432 else if (jobno == prev && ps == jp->ps)
433 c = '-';
434 else
435 c = ' ';
436 if (ps == jp->ps)
437 fmtstr(s, 64, "[%d] %c ", jobno, c);
438 else
439 fmtstr(s, 64, " %c ", c);
440 out1str(s);
441 col = strlen(s);
442 if (mode == SHOWJOBS_VERBOSE) {
443 fmtstr(s, 64, "%d ", (int)ps->pid);
444 out1str(s);
445 col += strlen(s);
446 }
447 if (ps == jp->ps) {
448 out1str(statestr);
449 out1str(coredump);
450 col += strlen(statestr) + strlen(coredump);
451 }
452 do {
453 out1c(' ');
454 col++;
455 } while (col < 30);
456 if (mode == SHOWJOBS_VERBOSE) {
457 out1str(ps->cmd);
458 out1c('\n');
459 } else
460 printjobcmd(jp);
461 }
462}
463
464/*
465 * Print a list of jobs. If "change" is nonzero, only print jobs whose
466 * statuses have changed since the last call to showjobs.
467 *
468 * If the shell is interrupted in the process of creating a job, the
469 * result may be a job structure containing zero processes. Such structures
470 * will be freed here.
471 */
472
473void
474showjobs(int change, int mode)
475{
476 int jobno;
477 struct job *jp;
478
479 TRACE(("showjobs(%d) called\n", change));
480 checkzombies();
481 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
482 if (! jp->used)
483 continue;
484 if (jp->nprocs == 0) {
485 freejob(jp);
486 continue;
487 }
488 if (change && ! jp->changed)
489 continue;
490 showjob(jp, mode);
491 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) {
492 jp->changed = 0;
493 /* Hack: discard jobs for which $! has not been
494 * referenced in interactive mode when they terminate.
495 */
496 if (jp->state == JOBDONE && !jp->remembered &&
497 (iflag || jp != bgjob)) {
498 freejob(jp);
499 }
500 }
501 }
502}
503
504
505/*
506 * Mark a job structure as unused.
507 */
508
509static void
510freejob(struct job *jp)
511{
512 struct procstat *ps;
513 int i;
514
515 INTOFF;
516 if (bgjob == jp)
517 bgjob = NULL;
518 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
519 if (ps->cmd != nullstr)
520 ckfree(ps->cmd);
521 }
522 if (jp->ps != &jp->ps0)
523 ckfree(jp->ps);
524 jp->used = 0;
525#if JOBS
526 deljob(jp);
527#endif
528 INTON;
529}
530
531
532
533int
534waitcmd(int argc __unused, char **argv __unused)
535{
536 struct job *job;
537 int retval;
538
539 nextopt("");
540 if (*argptr == NULL)
541 return (waitcmdloop(NULL));
542
543 do {
544 job = getjob_nonotfound(*argptr);
545 if (job == NULL)
546 retval = 127;
547 else
548 retval = waitcmdloop(job);
549 argptr++;
550 } while (*argptr != NULL);
551
552 return (retval);
553}
554
555static int
556waitcmdloop(struct job *job)
557{
558 int status, retval, sig;
559 struct job *jp;
560
561 /*
562 * Loop until a process is terminated or stopped, or a SIGINT is
563 * received.
564 */
565
566 do {
567 if (job != NULL) {
568 if (job->state == JOBDONE) {
569 status = getjobstatus(job);
570 if (WIFEXITED(status))
571 retval = WEXITSTATUS(status);
572 else
573 retval = WTERMSIG(status) + 128;
574 if (! iflag || ! job->changed)
575 freejob(job);
576 else {
577 job->remembered = 0;
578 deljob(job);
579 if (job == bgjob)
580 bgjob = NULL;
581 }
582 return retval;
583 }
584 } else {
585 if (njobs == 0)
586 return 0;
587 for (jp = jobtab ; jp < jobtab + njobs; jp++)
588 if (jp->used && jp->state == JOBDONE) {
589 if (! iflag || ! jp->changed)
590 freejob(jp);
591 else {
592 jp->remembered = 0;
593 if (jp == bgjob)
594 bgjob = NULL;
595 }
596 }
597 for (jp = jobtab ; ; jp++) {
598 if (jp >= jobtab + njobs) { /* no running procs */
599 return 0;
600 }
601 if (jp->used && jp->state == 0)
602 break;
603 }
604 }
605 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, job) != -1);
606
607 sig = pendingsig_waitcmd;
608 pendingsig_waitcmd = 0;
609 return sig + 128;
610}
611
612
613
614int
615jobidcmd(int argc __unused, char **argv __unused)
616{
617 struct job *jp;
618 int i;
619
620 nextopt("");
621 jp = getjob(*argptr);
622 for (i = 0 ; i < jp->nprocs ; ) {
623 out1fmt("%d", (int)jp->ps[i].pid);
624 out1c(++i < jp->nprocs? ' ' : '\n');
625 }
626 return 0;
627}
628
629
630
631/*
632 * Convert a job name to a job structure.
633 */
634
635static struct job *
636getjob_nonotfound(const char *name)
637{
638 int jobno;
639 struct job *found, *jp;
640 size_t namelen;
641 pid_t pid;
642 int i;
643
644 if (name == NULL) {
645#if JOBS
646 name = "%+";
647#else
648 error("No current job");
649#endif
650 }
651 if (name[0] == '%') {
652 if (is_digit(name[1])) {
653 jobno = number(name + 1);
654 if (jobno > 0 && jobno <= njobs
655 && jobtab[jobno - 1].used != 0)
656 return &jobtab[jobno - 1];
657#if JOBS
658 } else if ((name[1] == '%' || name[1] == '+') &&
659 name[2] == '\0') {
660 if ((jp = getcurjob(NULL)) == NULL)
661 error("No current job");
662 return (jp);
663 } else if (name[1] == '-' && name[2] == '\0') {
664 if ((jp = getcurjob(NULL)) == NULL ||
665 (jp = getcurjob(jp)) == NULL)
666 error("No previous job");
667 return (jp);
668#endif
669 } else if (name[1] == '?') {
670 found = NULL;
671 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
672 if (jp->used && jp->nprocs > 0
673 && strstr(jp->ps[0].cmd, name + 2) != NULL) {
674 if (found)
675 error("%s: ambiguous", name);
676 found = jp;
677 }
678 }
679 if (found != NULL)
680 return (found);
681 } else {
682 namelen = strlen(name);
683 found = NULL;
684 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
685 if (jp->used && jp->nprocs > 0
686 && strncmp(jp->ps[0].cmd, name + 1,
687 namelen - 1) == 0) {
688 if (found)
689 error("%s: ambiguous", name);
690 found = jp;
691 }
692 }
693 if (found)
694 return found;
695 }
696 } else if (is_number(name)) {
697 pid = (pid_t)number(name);
698 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
699 if (jp->used && jp->nprocs > 0
700 && jp->ps[jp->nprocs - 1].pid == pid)
701 return jp;
702 }
703 }
704 return NULL;
705}
706
707
708static struct job *
709getjob(const char *name)
710{
711 struct job *jp;
712
713 jp = getjob_nonotfound(name);
714 if (jp == NULL)
715 error("No such job: %s", name);
716 return (jp);
717}
718
719
720int
721killjob(const char *name, int sig)
722{
723 struct job *jp;
724 int i, ret;
725
726 jp = getjob(name);
727 if (jp->state == JOBDONE)
728 return 0;
729 if (jp->jobctl)
730 return kill(-jp->ps[0].pid, sig);
731 ret = -1;
732 errno = ESRCH;
733 for (i = 0; i < jp->nprocs; i++)
734 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) {
735 if (kill(jp->ps[i].pid, sig) == 0)
736 ret = 0;
737 } else
738 ret = 0;
739 return ret;
740}
741
742/*
743 * Return a new job structure,
744 */
745
746struct job *
747makejob(union node *node __unused, int nprocs)
748{
749 int i;
750 struct job *jp;
751
752 for (i = njobs, jp = jobtab ; ; jp++) {
753 if (--i < 0) {
754 INTOFF;
755 if (njobs == 0) {
756 jobtab = ckmalloc(4 * sizeof jobtab[0]);
757#if JOBS
758 jobmru = NULL;
759#endif
760 } else {
761 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
762 memcpy(jp, jobtab, njobs * sizeof jp[0]);
763#if JOBS
764 /* Relocate `next' pointers and list head */
765 if (jobmru != NULL)
766 jobmru = &jp[jobmru - jobtab];
767 for (i = 0; i < njobs; i++)
768 if (jp[i].next != NULL)
769 jp[i].next = &jp[jp[i].next -
770 jobtab];
771#endif
772 if (bgjob != NULL)
773 bgjob = &jp[bgjob - jobtab];
774 /* Relocate `ps' pointers */
775 for (i = 0; i < njobs; i++)
776 if (jp[i].ps == &jobtab[i].ps0)
777 jp[i].ps = &jp[i].ps0;
778 ckfree(jobtab);
779 jobtab = jp;
780 }
781 jp = jobtab + njobs;
782 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0)
783 ;
784 INTON;
785 break;
786 }
787 if (jp->used == 0)
788 break;
789 }
790 INTOFF;
791 jp->state = 0;
792 jp->used = 1;
793 jp->changed = 0;
794 jp->nprocs = 0;
795 jp->foreground = 0;
796 jp->remembered = 0;
797 jp->pipefail = pipefailflag;
798#if JOBS
799 jp->jobctl = jobctl;
800 jp->next = NULL;
801#endif
802 if (nprocs > 1) {
803 jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
804 } else {
805 jp->ps = &jp->ps0;
806 }
807 INTON;
808 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
809 jp - jobtab + 1));
810 return jp;
811}
812
813#if JOBS
814static void
815setcurjob(struct job *cj)
816{
817 struct job *jp, *prev;
818
819 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
820 if (jp == cj) {
821 if (prev != NULL)
822 prev->next = jp->next;
823 else
824 jobmru = jp->next;
825 jp->next = jobmru;
826 jobmru = cj;
827 return;
828 }
829 }
830 cj->next = jobmru;
831 jobmru = cj;
832}
833
834static void
835deljob(struct job *j)
836{
837 struct job *jp, *prev;
838
839 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
840 if (jp == j) {
841 if (prev != NULL)
842 prev->next = jp->next;
843 else
844 jobmru = jp->next;
845 return;
846 }
847 }
848}
849
850/*
851 * Return the most recently used job that isn't `nj', and preferably one
852 * that is stopped.
853 */
854static struct job *
855getcurjob(struct job *nj)
856{
857 struct job *jp;
858
859 /* Try to find a stopped one.. */
860 for (jp = jobmru; jp != NULL; jp = jp->next)
861 if (jp->used && jp != nj && jp->state == JOBSTOPPED)
862 return (jp);
863 /* Otherwise the most recently used job that isn't `nj' */
864 for (jp = jobmru; jp != NULL; jp = jp->next)
865 if (jp->used && jp != nj)
866 return (jp);
867
868 return (NULL);
869}
870
871#endif
872
873/*
874 * Fork of a subshell. If we are doing job control, give the subshell its
875 * own process group. Jp is a job structure that the job is to be added to.
876 * N is the command that will be evaluated by the child. Both jp and n may
877 * be NULL. The mode parameter can be one of the following:
878 * FORK_FG - Fork off a foreground process.
879 * FORK_BG - Fork off a background process.
880 * FORK_NOJOB - Like FORK_FG, but don't give the process its own
881 * process group even if job control is on.
882 *
883 * When job control is turned off, background processes have their standard
884 * input redirected to /dev/null (except for the second and later processes
885 * in a pipeline).
886 */
887
888pid_t
889forkshell(struct job *jp, union node *n, int mode)
890{
891 pid_t pid;
892 pid_t pgrp;
893
894 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
895 mode));
896 INTOFF;
897 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
898 checkzombies();
899 flushall();
900 pid = fork();
901 if (pid == -1) {
902 TRACE(("Fork failed, errno=%d\n", errno));
903 INTON;
904 error("Cannot fork: %s", strerror(errno));
905 }
906 if (pid == 0) {
907 struct job *p;
908 int wasroot;
909 int i;
910
911 TRACE(("Child shell %d\n", (int)getpid()));
912 wasroot = rootshell;
913 rootshell = 0;
914 handler = &main_handler;
915 closescript();
916 INTON;
917 forcelocal = 0;
918 clear_traps();
919#if JOBS
920 jobctl = 0; /* do job control only in root shell */
921 if (wasroot && mode != FORK_NOJOB && mflag) {
922 if (jp == NULL || jp->nprocs == 0)
923 pgrp = getpid();
924 else
925 pgrp = jp->ps[0].pid;
926 if (setpgid(0, pgrp) == 0 && mode == FORK_FG &&
927 ttyfd >= 0) {
928 /*
929 * Each process in a pipeline must have the tty
930 * pgrp set before running its code.
931 * Only for pipelines of three or more processes
932 * could this be reduced to two calls.
933 */
934 if (tcsetpgrp(ttyfd, pgrp) < 0)
935 error("tcsetpgrp failed, errno=%d", errno);
936 }
937 setsignal(SIGTSTP);
938 setsignal(SIGTTOU);
939 } else if (mode == FORK_BG) {
940 ignoresig(SIGINT);
941 ignoresig(SIGQUIT);
942 if ((jp == NULL || jp->nprocs == 0) &&
943 ! fd0_redirected_p ()) {
944 close(0);
945 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
946 error("cannot open %s: %s",
947 _PATH_DEVNULL, strerror(errno));
948 }
949 }
950#else
951 if (mode == FORK_BG) {
952 ignoresig(SIGINT);
953 ignoresig(SIGQUIT);
954 if ((jp == NULL || jp->nprocs == 0) &&
955 ! fd0_redirected_p ()) {
956 close(0);
957 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
958 error("cannot open %s: %s",
959 _PATH_DEVNULL, strerror(errno));
960 }
961 }
962#endif
963 INTOFF;
964 for (i = njobs, p = jobtab ; --i >= 0 ; p++)
965 if (p->used)
966 freejob(p);
967 INTON;
968 if (wasroot && iflag) {
969 setsignal(SIGINT);
970 setsignal(SIGQUIT);
971 setsignal(SIGTERM);
972 }
973 return pid;
974 }
975 if (rootshell && mode != FORK_NOJOB && mflag) {
976 if (jp == NULL || jp->nprocs == 0)
977 pgrp = pid;
978 else
979 pgrp = jp->ps[0].pid;
980 setpgid(pid, pgrp);
981 }
982 if (mode == FORK_BG) {
983 if (bgjob != NULL && bgjob->state == JOBDONE &&
984 !bgjob->remembered && !iflag)
985 freejob(bgjob);
986 backgndpid = pid; /* set $! */
987 bgjob = jp;
988 }
989 if (jp) {
990 struct procstat *ps = &jp->ps[jp->nprocs++];
991 ps->pid = pid;
992 ps->status = -1;
993 ps->cmd = nullstr;
994 if (iflag && rootshell && n)
995 ps->cmd = commandtext(n);
996 jp->foreground = mode == FORK_FG;
997#if JOBS
998 setcurjob(jp);
999#endif
1000 }
1001 INTON;
1002 TRACE(("In parent shell: child = %d\n", (int)pid));
1003 return pid;
1004}
1005
1006
1007pid_t
1008vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
1009{
1010 pid_t pid;
1011 struct jmploc jmploc;
1012 struct jmploc *savehandler;
1013 int inton;
1014
1015 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
1016 (void *)pip));
1017 inton = is_int_on();
1018 INTOFF;
1019 flushall();
1020 savehandler = handler;
1021 pid = vfork();
1022 if (pid == -1) {
1023 TRACE(("Vfork failed, errno=%d\n", errno));
1024 INTON;
1025 error("Cannot fork: %s", strerror(errno));
1026 }
1027 if (pid == 0) {
1028 TRACE(("Child shell %d\n", (int)getpid()));
1029 if (setjmp(jmploc.loc))
1030 _exit(exitstatus);
1031 if (pip != NULL) {
1032 close(pip[0]);
1033 if (pip[1] != 1) {
1034 dup2(pip[1], 1);
1035 close(pip[1]);
1036 }
1037 }
1038 handler = &jmploc;
1039 shellexec(argv, envp, path, idx);
1040 }
1041 handler = savehandler;
1042 if (jp) {
1043 struct procstat *ps = &jp->ps[jp->nprocs++];
1044 ps->pid = pid;
1045 ps->status = -1;
1046 ps->cmd = nullstr;
1047 jp->foreground = 1;
1048#if JOBS
1049 setcurjob(jp);
1050#endif
1051 }
1052 SETINTON(inton);
1053 TRACE(("In parent shell: child = %d\n", (int)pid));
1054 return pid;
1055}
1056
1057
1058/*
1059 * Wait for job to finish.
1060 *
1061 * Under job control we have the problem that while a child process is
1062 * running interrupts generated by the user are sent to the child but not
1063 * to the shell. This means that an infinite loop started by an inter-
1064 * active user may be hard to kill. With job control turned off, an
1065 * interactive user may place an interactive program inside a loop. If
1066 * the interactive program catches interrupts, the user doesn't want
1067 * these interrupts to also abort the loop. The approach we take here
1068 * is to have the shell ignore interrupt signals while waiting for a
1069 * foreground process to terminate, and then send itself an interrupt
1070 * signal if the child process was terminated by an interrupt signal.
1071 * Unfortunately, some programs want to do a bit of cleanup and then
1072 * exit on interrupt; unless these processes terminate themselves by
1073 * sending a signal to themselves (instead of calling exit) they will
1074 * confuse this approach.
1075 */
1076
1077int
1078waitforjob(struct job *jp, int *signaled)
1079{
1080#if JOBS
1081 int propagate_int = jp->jobctl && jp->foreground;
1082#endif
1083 int jobindex;
1084 int status;
1085 int st;
1086
1087 INTOFF;
1088 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
1089 while (jp->state == 0)
1090 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG |
1091 DOWAIT_SIG_TRAP : 0), jp) == -1) {
1092 jobindex = jp - jobtab;
1093 dotrap();
1094 jp = jobtab + jobindex;
1095 }
1096#if JOBS
1097 if (jp->jobctl) {
1098 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0)
1099 error("tcsetpgrp failed, errno=%d\n", errno);
1100 }
1101 if (jp->state == JOBSTOPPED)
1102 setcurjob(jp);
1103#endif
1104 status = getjobstatus(jp);
1105 if (signaled != NULL)
1106 *signaled = WIFSIGNALED(status);
1107 /* convert to 8 bits */
1108 if (WIFEXITED(status))
1109 st = WEXITSTATUS(status);
1110#if JOBS
1111 else if (WIFSTOPPED(status))
1112 st = WSTOPSIG(status) + 128;
1113#endif
1114 else
1115 st = WTERMSIG(status) + 128;
1116 if (! JOBS || jp->state == JOBDONE)
1117 freejob(jp);
1118 if (int_pending()) {
1119 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
1120 CLEAR_PENDING_INT;
1121 }
1122#if JOBS
1123 else if (rootshell && propagate_int &&
1124 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1125 kill(getpid(), SIGINT);
1126#endif
1127 INTON;
1128 return st;
1129}
1130
1131
1132static void
1133dummy_handler(int sig __unused)
1134{
1135}
1136
1137/*
1138 * Wait for a process to terminate.
1139 */
1140
1141static pid_t
1142dowait(int mode, struct job *job)
1143{
1144 struct sigaction sa, osa;
1145 sigset_t mask, omask;
1146 pid_t pid;
1147 int status;
1148 struct procstat *sp;
1149 struct job *jp;
1150 struct job *thisjob;
1151 const char *sigstr;
1152 int done;
1153 int stopped;
1154 int sig;
1155 int coredump;
1156 int wflags;
1157 int restore_sigchld;
1158
1159 TRACE(("dowait(%d, %p) called\n", mode, job));
1160 restore_sigchld = 0;
1161 if ((mode & DOWAIT_SIG) != 0) {
1162 sigfillset(&mask);
1163 sigprocmask(SIG_BLOCK, &mask, &omask);
1164 INTOFF;
1165 if (!issigchldtrapped()) {
1166 restore_sigchld = 1;
1167 sa.sa_handler = dummy_handler;
1168 sa.sa_flags = 0;
1169 sigemptyset(&sa.sa_mask);
1170 sigaction(SIGCHLD, &sa, &osa);
1171 }
1172 }
1173 do {
1174#if JOBS
1175 if (iflag)
1176 wflags = WUNTRACED | WCONTINUED;
1177 else
1178#endif
1179 wflags = 0;
1180 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
1181 wflags |= WNOHANG;
1182 pid = wait3(&status, wflags, (struct rusage *)NULL);
1183 TRACE(("wait returns %d, status=%d\n", (int)pid, status));
1184 if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
1185 pid = -1;
1186 if (((mode & DOWAIT_SIG_TRAP) != 0 ?
1187 pendingsig : pendingsig_waitcmd) != 0) {
1188 errno = EINTR;
1189 break;
1190 }
1191 sigsuspend(&omask);
1192 if (int_pending())
1193 break;
1194 }
1195 } while (pid == -1 && errno == EINTR);
1196 if (pid == -1 && errno == ECHILD && job != NULL)
1197 job->state = JOBDONE;
1198 if ((mode & DOWAIT_SIG) != 0) {
1199 if (restore_sigchld)
1200 sigaction(SIGCHLD, &osa, NULL);
1201 sigprocmask(SIG_SETMASK, &omask, NULL);
1202 INTON;
1203 }
1204 if (pid <= 0)
1205 return pid;
1206 INTOFF;
1207 thisjob = NULL;
1208 for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1209 if (jp->used && jp->nprocs > 0) {
1210 done = 1;
1211 stopped = 1;
1212 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1213 if (sp->pid == -1)
1214 continue;
1215 if (sp->pid == pid && (sp->status == -1 ||
1216 WIFSTOPPED(sp->status))) {
1217 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
1218 (int)pid, sp->status,
1219 status));
1220 if (WIFCONTINUED(status)) {
1221 sp->status = -1;
1222 jp->state = 0;
1223 } else
1224 sp->status = status;
1225 thisjob = jp;
1226 }
1227 if (sp->status == -1)
1228 stopped = 0;
1229 else if (WIFSTOPPED(sp->status))
1230 done = 0;
1231 }
1232 if (stopped) { /* stopped or done */
1233 int state = done? JOBDONE : JOBSTOPPED;
1234 if (jp->state != state) {
1235 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1236 jp->state = state;
1237 if (jp != job) {
1238 if (done && !jp->remembered &&
1239 !iflag && jp != bgjob)
1240 freejob(jp);
1241#if JOBS
1242 else if (done)
1243 deljob(jp);
1244#endif
1245 }
1246 }
1247 }
1248 }
1249 }
1250 INTON;
1251 if (!thisjob || thisjob->state == 0)
1252 ;
1253 else if ((!rootshell || !iflag || thisjob == job) &&
1254 thisjob->foreground && thisjob->state != JOBSTOPPED) {
1255 sig = 0;
1256 coredump = 0;
1257 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
1258 if (WIFSIGNALED(sp->status)) {
1259 sig = WTERMSIG(sp->status);
1260 coredump = WCOREDUMP(sp->status);
1261 }
1262 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
1263 sigstr = strsignal(sig);
1264 if (sigstr != NULL)
1265 out2str(sigstr);
1266 else
1267 out2str("Unknown signal");
1268 if (coredump)
1269 out2str(" (core dumped)");
1270 out2c('\n');
1271 flushout(out2);
1272 }
1273 } else {
1274 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
1275 thisjob->changed = 1;
1276 }
1277 return pid;
1278}
1279
1280
1281
1282/*
1283 * return 1 if there are stopped jobs, otherwise 0
1284 */
1285int job_warning = 0;
1286int
1287stoppedjobs(void)
1288{
1289 int jobno;
1290 struct job *jp;
1291
1292 if (job_warning)
1293 return (0);
1294 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1295 if (jp->used == 0)
1296 continue;
1297 if (jp->state == JOBSTOPPED) {
1298 out2fmt_flush("You have stopped jobs.\n");
1299 job_warning = 2;
1300 return (1);
1301 }
1302 }
1303
1304 return (0);
1305}
1306
1307
1308static void
1309checkzombies(void)
1310{
1311 while (njobs > 0 && dowait(0, NULL) > 0)
1312 ;
1313}
1314
1315
1316int
1317backgndpidset(void)
1318{
1319 return backgndpid != -1;
1320}
1321
1322
1323pid_t
1324backgndpidval(void)
1325{
1326 if (bgjob != NULL && !forcelocal)
1327 bgjob->remembered = 1;
1328 return backgndpid;
1329}
1330
1331/*
1332 * Return a string identifying a command (to be printed by the
1333 * jobs command.
1334 */
1335
1336static char *cmdnextc;
1337static int cmdnleft;
1338#define MAXCMDTEXT 200
1339
1340char *
1341commandtext(union node *n)
1342{
1343 char *name;
1344
1345 cmdnextc = name = ckmalloc(MAXCMDTEXT);
1346 cmdnleft = MAXCMDTEXT - 4;
1347 cmdtxt(n);
1348 *cmdnextc = '\0';
1349 return name;
1350}
1351
1352
1353static void
1354cmdtxtdogroup(union node *n)
1355{
1356 cmdputs("; do ");
1357 cmdtxt(n);
1358 cmdputs("; done");
1359}
1360
1361
1362static void
1363cmdtxtredir(union node *n, const char *op, int deffd)
1364{
1365 char s[2];
1366
1367 if (n->nfile.fd != deffd) {
1368 s[0] = n->nfile.fd + '0';
1369 s[1] = '\0';
1370 cmdputs(s);
1371 }
1372 cmdputs(op);
1373 if (n->type == NTOFD || n->type == NFROMFD) {
1374 if (n->ndup.dupfd >= 0)
1375 s[0] = n->ndup.dupfd + '0';
1376 else
1377 s[0] = '-';
1378 s[1] = '\0';
1379 cmdputs(s);
1380 } else {
1381 cmdtxt(n->nfile.fname);
1382 }
1383}
1384
1385
1386static void
1387cmdtxt(union node *n)
1388{
1389 union node *np;
1390 struct nodelist *lp;
1391
1392 if (n == NULL)
1393 return;
1394 switch (n->type) {
1395 case NSEMI:
1396 cmdtxt(n->nbinary.ch1);
1397 cmdputs("; ");
1398 cmdtxt(n->nbinary.ch2);
1399 break;
1400 case NAND:
1401 cmdtxt(n->nbinary.ch1);
1402 cmdputs(" && ");
1403 cmdtxt(n->nbinary.ch2);
1404 break;
1405 case NOR:
1406 cmdtxt(n->nbinary.ch1);
1407 cmdputs(" || ");
1408 cmdtxt(n->nbinary.ch2);
1409 break;
1410 case NPIPE:
1411 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1412 cmdtxt(lp->n);
1413 if (lp->next)
1414 cmdputs(" | ");
1415 }
1416 break;
1417 case NSUBSHELL:
1418 cmdputs("(");
1419 cmdtxt(n->nredir.n);
1420 cmdputs(")");
1421 break;
1422 case NREDIR:
1423 case NBACKGND:
1424 cmdtxt(n->nredir.n);
1425 break;
1426 case NIF:
1427 cmdputs("if ");
1428 cmdtxt(n->nif.test);
1429 cmdputs("; then ");
1430 cmdtxt(n->nif.ifpart);
1431 cmdputs("...");
1432 break;
1433 case NWHILE:
1434 cmdputs("while ");
1435 cmdtxt(n->nbinary.ch1);
1436 cmdtxtdogroup(n->nbinary.ch2);
1437 break;
1438 case NUNTIL:
1439 cmdputs("until ");
1440 cmdtxt(n->nbinary.ch1);
1441 cmdtxtdogroup(n->nbinary.ch2);
1442 break;
1443 case NFOR:
1444 cmdputs("for ");
1445 cmdputs(n->nfor.var);
1446 cmdputs(" in ...");
1447 break;
1448 case NCASE:
1449 cmdputs("case ");
1450 cmdputs(n->ncase.expr->narg.text);
1451 cmdputs(" in ...");
1452 break;
1453 case NDEFUN:
1454 cmdputs(n->narg.text);
1455 cmdputs("() ...");
1456 break;
1457 case NNOT:
1458 cmdputs("! ");
1459 cmdtxt(n->nnot.com);
1460 break;
1461 case NCMD:
1462 for (np = n->ncmd.args ; np ; np = np->narg.next) {
1463 cmdtxt(np);
1464 if (np->narg.next)
1465 cmdputs(" ");
1466 }
1467 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
1468 cmdputs(" ");
1469 cmdtxt(np);
1470 }
1471 break;
1472 case NARG:
1473 cmdputs(n->narg.text);
1474 break;
1475 case NTO:
1476 cmdtxtredir(n, ">", 1);
1477 break;
1478 case NAPPEND:
1479 cmdtxtredir(n, ">>", 1);
1480 break;
1481 case NTOFD:
1482 cmdtxtredir(n, ">&", 1);
1483 break;
1484 case NCLOBBER:
1485 cmdtxtredir(n, ">|", 1);
1486 break;
1487 case NFROM:
1488 cmdtxtredir(n, "<", 0);
1489 break;
1490 case NFROMTO:
1491 cmdtxtredir(n, "<>", 0);
1492 break;
1493 case NFROMFD:
1494 cmdtxtredir(n, "<&", 0);
1495 break;
1496 case NHERE:
1497 case NXHERE:
1498 cmdputs("<<...");
1499 break;
1500 default:
1501 cmdputs("???");
1502 break;
1503 }
1504}
1505
1506
1507
1508static void
1509cmdputs(const char *s)
1510{
1511 const char *p;
1512 char *q;
1513 char c;
1514 int subtype = 0;
1515
1516 if (cmdnleft <= 0)
1517 return;
1518 p = s;
1519 q = cmdnextc;
1520 while ((c = *p++) != '\0') {
1521 if (c == CTLESC)
1522 *q++ = *p++;
1523 else if (c == CTLVAR) {
1524 *q++ = '$';
1525 if (--cmdnleft > 0)
1526 *q++ = '{';
1527 subtype = *p++;
1528 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
1529 *q++ = '#';
1530 } else if (c == '=' && subtype != 0) {
1531 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
1532 if (*q)
1533 q++;
1534 else
1535 cmdnleft++;
1536 if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
1537 (subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
1538 --cmdnleft > 0)
1539 *q = q[-1], q++;
1540 subtype = 0;
1541 } else if (c == CTLENDVAR) {
1542 *q++ = '}';
1543 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
1544 cmdnleft -= 5;
1545 if (cmdnleft > 0) {
1546 *q++ = '$';
1547 *q++ = '(';
1548 *q++ = '.';
1549 *q++ = '.';
1550 *q++ = '.';
1551 *q++ = ')';
1552 }
1553 } else if (c == CTLARI) {
1554 cmdnleft -= 2;
1555 if (cmdnleft > 0) {
1556 *q++ = '$';
1557 *q++ = '(';
1558 *q++ = '(';
1559 }
1560 p++;
1561 } else if (c == CTLENDARI) {
1562 if (--cmdnleft > 0) {
1563 *q++ = ')';
1564 *q++ = ')';
1565 }
1566 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
1567 cmdnleft++; /* ignore */
1568 else
1569 *q++ = c;
1570 if (--cmdnleft <= 0) {
1571 *q++ = '.';
1572 *q++ = '.';
1573 *q++ = '.';
1574 break;
1575 }
1576 }
1577 cmdnextc = q;
1578}
