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