1 /* $NetBSD: jobs.c,v 1.62 2003/12/18 00:56:05 christos Exp $ */
2
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/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95";
39 #else
40 __RCSID("$NetBSD: jobs.c,v 1.62 2003/12/18 00:56:05 christos Exp $");
41 #endif
42 #endif /* not lint */
43
44 #include <fcntl.h>
45 #include <signal.h>
46 #include <errno.h>
47 #include <unistd.h>
48 #include <stdlib.h>
49 #define _PATH_DEVNULL "/dev/null"
50 #include <sys/types.h>
51 #include <sys/param.h>
52 #ifdef BSD
53 #include <sys/wait.h>
54 #include <sys/time.h>
55 #include <sys/resource.h>
56 #endif
57 #include <sys/wait.h>
58 #define killpg(s,i) kill(-(s),i)
59 #include <sys/ioctl.h>
60
61 #include "shell.h"
62 #if JOBS
63 #if OLD_TTY_DRIVER
64 #include "sgtty.h"
65 #else
66 #include <termios.h>
67 #endif
68 #undef CEOF /* syntax.h redefines this */
69 #endif
70 #include "redir.h"
71 #include "show.h"
72 #include "main.h"
73 #include "parser.h"
74 #include "nodes.h"
75 #include "jobs.h"
76 #include "options.h"
77 #include "trap.h"
78 #include "syntax.h"
79 #include "input.h"
80 #include "output.h"
81 #include "memalloc.h"
82 #include "error.h"
83 #include "mystring.h"
84
85 // Use of process groups is disabled to allow adb shell children to terminate when the shell dies
86 #define USE_PROCESS_GROUPS
87
88
89 static struct job *jobtab; /* array of jobs */
90 static int njobs; /* size of array */
91 static int jobs_invalid; /* set in child */
92 MKINIT pid_t backgndpid = -1; /* pid of last background process */
93 #if JOBS
94 int initialpgrp; /* pgrp of shell on invocation */
95 static int curjob = -1; /* current job */
96 #endif
97 static int ttyfd = -1;
98
99 STATIC void restartjob(struct job *);
100 STATIC void freejob(struct job *);
101 STATIC struct job *getjob(const char *, int);
102 STATIC int dowait(int, struct job *);
103 STATIC int onsigchild(void);
104 STATIC int waitproc(int, struct job *, int *);
105 STATIC void cmdtxt(union node *);
106 STATIC void cmdlist(union node *, int);
107 STATIC void cmdputs(const char *);
108
109 #ifdef OLD_TTY_DRIVER
110 static pid_t tcgetpgrp(int fd);
111 static int tcsetpgrp(int fd, pid_t pgrp);
112
113 static pid_t
tcgetpgrp(int fd)114 tcgetpgrp(int fd)
115 {
116 pid_t pgrp;
117 if (ioctl(fd, TIOCGPGRP, (char *)&pgrp) == -1)
118 return -1;
119 else
120 return pgrp;
121 }
122
123 static int
tcsetpgrp(int fd,pid_tpgrp)124 tcsetpgrp(int fd, pid_tpgrp)
125 {
126 return ioctl(fd, TIOCSPGRP, (char *)&pgrp);
127 }
128 #endif
129
130 /*
131 * Turn job control on and off.
132 *
133 * Note: This code assumes that the third arg to ioctl is a character
134 * pointer, which is true on Berkeley systems but not System V. Since
135 * System V doesn't have job control yet, this isn't a problem now.
136 */
137
138 MKINIT int jobctl;
139
140 void
setjobctl(int on)141 setjobctl(int on)
142 {
143 #ifdef OLD_TTY_DRIVER
144 int ldisc;
145 #endif
146
147 if (on == jobctl || rootshell == 0)
148 return;
149 if (on) {
150 #if defined(FIOCLEX) || defined(FD_CLOEXEC)
151 int err;
152 int i;
153 if (ttyfd != -1)
154 close(ttyfd);
155 if ((ttyfd = open("/dev/tty", O_RDWR)) == -1) {
156 for (i = 0; i < 3; i++) {
157 if (isatty(i) && (ttyfd = dup(i)) != -1)
158 break;
159 }
160 if (i == 3)
161 goto out;
162 }
163 /* Move to a high fd */
164 for (i = 10; i > 2; i--) {
165 if ((err = fcntl(ttyfd, F_DUPFD, (1 << i) - 1)) != -1)
166 break;
167 }
168 if (err != -1) {
169 close(ttyfd);
170 ttyfd = err;
171 }
172 #ifdef FIOCLEX
173 err = ioctl(ttyfd, FIOCLEX, 0);
174 #elif FD_CLOEXEC
175 err = fcntl(ttyfd, F_SETFD,
176 fcntl(ttyfd, F_GETFD, 0) | FD_CLOEXEC);
177 #endif
178 if (err == -1) {
179 close(ttyfd);
180 ttyfd = -1;
181 goto out;
182 }
183 #else
184 out2str("sh: Need FIOCLEX or FD_CLOEXEC to support job control");
185 goto out;
186 #endif
187 do { /* while we are in the background */
188 if ((initialpgrp = tcgetpgrp(ttyfd)) < 0) {
189 out:
190 out2str("sh: can't access tty; job control turned off\n");
191 mflag = 0;
192 return;
193 }
194 if (initialpgrp == -1)
195 initialpgrp = getpgrp();
196 else if (initialpgrp != getpgrp()) {
197 killpg(0, SIGTTIN);
198 continue;
199 }
200 } while (0);
201
202 #ifdef OLD_TTY_DRIVER
203 if (ioctl(ttyfd, TIOCGETD, (char *)&ldisc) < 0
204 || ldisc != NTTYDISC) {
205 out2str("sh: need new tty driver to run job control; job control turned off\n");
206 mflag = 0;
207 return;
208 }
209 #endif
210 setsignal(SIGTSTP, 0);
211 setsignal(SIGTTOU, 0);
212 setsignal(SIGTTIN, 0);
213 #ifdef USE_PROCESS_GROUPS
214 if (getpgid(0) != rootpid && setpgid(0, rootpid) == -1)
215 error("Cannot set process group (%s) at %d",
216 strerror(errno), __LINE__);
217 if (tcsetpgrp(ttyfd, rootpid) == -1)
218 error("Cannot set tty process group (%s) at %d",
219 strerror(errno), __LINE__);
220 #endif
221 } else { /* turning job control off */
222 #ifdef USE_PROCESS_GROUPS
223 if (getpgid(0) != initialpgrp && setpgid(0, initialpgrp) == -1)
224 error("Cannot set process group (%s) at %d",
225 strerror(errno), __LINE__);
226 if (tcsetpgrp(ttyfd, initialpgrp) == -1)
227 error("Cannot set tty process group (%s) at %d",
228 strerror(errno), __LINE__);
229 #endif
230 close(ttyfd);
231 ttyfd = -1;
232 setsignal(SIGTSTP, 0);
233 setsignal(SIGTTOU, 0);
234 setsignal(SIGTTIN, 0);
235 }
236 jobctl = on;
237 }
238
239
240 #ifdef mkinit
241 INCLUDE <stdlib.h>
242
243 SHELLPROC {
244 backgndpid = -1;
245 #if JOBS
246 jobctl = 0;
247 #endif
248 }
249
250 #endif
251
252
253
254 #if JOBS
255 int
fgcmd(int argc,char ** argv)256 fgcmd(int argc, char **argv)
257 {
258 struct job *jp;
259 int i;
260 int status;
261
262 nextopt("");
263 jp = getjob(*argptr, 0);
264 if (jp->jobctl == 0)
265 error("job not created under job control");
266 out1fmt("%s", jp->ps[0].cmd);
267 for (i = 1; i < jp->nprocs; i++)
268 out1fmt(" | %s", jp->ps[i].cmd );
269 out1c('\n');
270 flushall();
271
272 for (i = 0; i < jp->nprocs; i++)
273 if (tcsetpgrp(ttyfd, jp->ps[i].pid) != -1)
274 break;
275
276 if (i >= jp->nprocs) {
277 error("Cannot set tty process group (%s) at %d",
278 strerror(errno), __LINE__);
279 }
280 restartjob(jp);
281 INTOFF;
282 status = waitforjob(jp);
283 INTON;
284 return status;
285 }
286
287 static void
set_curjob(struct job * jp,int mode)288 set_curjob(struct job *jp, int mode)
289 {
290 struct job *jp1, *jp2;
291 int i, ji;
292
293 ji = jp - jobtab;
294
295 /* first remove from list */
296 if (ji == curjob)
297 curjob = jp->prev_job;
298 else {
299 for (i = 0; i < njobs; i++) {
300 if (jobtab[i].prev_job != ji)
301 continue;
302 jobtab[i].prev_job = jp->prev_job;
303 break;
304 }
305 }
306
307 /* Then re-insert in correct position */
308 switch (mode) {
309 case 0: /* job being deleted */
310 jp->prev_job = -1;
311 break;
312 case 1: /* newly created job or backgrounded job,
313 put after all stopped jobs. */
314 if (curjob != -1 && jobtab[curjob].state == JOBSTOPPED) {
315 for (jp1 = jobtab + curjob; ; jp1 = jp2) {
316 if (jp1->prev_job == -1)
317 break;
318 jp2 = jobtab + jp1->prev_job;
319 if (jp2->state != JOBSTOPPED)
320 break;
321 }
322 jp->prev_job = jp1->prev_job;
323 jp1->prev_job = ji;
324 break;
325 }
326 /* FALLTHROUGH */
327 case 2: /* newly stopped job - becomes curjob */
328 jp->prev_job = curjob;
329 curjob = ji;
330 break;
331 }
332 }
333
334 int
bgcmd(int argc,char ** argv)335 bgcmd(int argc, char **argv)
336 {
337 struct job *jp;
338 int i;
339
340 nextopt("");
341 do {
342 jp = getjob(*argptr, 0);
343 if (jp->jobctl == 0)
344 error("job not created under job control");
345 set_curjob(jp, 1);
346 out1fmt("[%ld] %s", (long)(jp - jobtab + 1), jp->ps[0].cmd);
347 for (i = 1; i < jp->nprocs; i++)
348 out1fmt(" | %s", jp->ps[i].cmd );
349 out1c('\n');
350 flushall();
351 restartjob(jp);
352 } while (*argptr && *++argptr);
353 return 0;
354 }
355
356
357 STATIC void
restartjob(struct job * jp)358 restartjob(struct job *jp)
359 {
360 struct procstat *ps;
361 int i;
362
363 if (jp->state == JOBDONE)
364 return;
365 INTOFF;
366 for (i = 0; i < jp->nprocs; i++)
367 if (killpg(jp->ps[i].pid, SIGCONT) != -1)
368 break;
369 if (i >= jp->nprocs)
370 error("Cannot continue job (%s)", strerror(errno));
371 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
372 if (WIFSTOPPED(ps->status)) {
373 ps->status = -1;
374 jp->state = JOBRUNNING;
375 }
376 }
377 INTON;
378 }
379 #endif
380
381 static void
showjob(struct output * out,struct job * jp,int mode)382 showjob(struct output *out, struct job *jp, int mode)
383 {
384 int procno;
385 int st;
386 struct procstat *ps;
387 int col;
388 char s[64];
389
390 #if JOBS
391 if (mode & SHOW_PGID) {
392 /* just output process (group) id of pipeline */
393 outfmt(out, "%ld\n", (long)jp->ps->pid);
394 return;
395 }
396 #endif
397
398 procno = jp->nprocs;
399 if (!procno)
400 return;
401
402 if (mode & SHOW_PID)
403 mode |= SHOW_MULTILINE;
404
405 if ((procno > 1 && !(mode & SHOW_MULTILINE))
406 || (mode & SHOW_SIGNALLED)) {
407 /* See if we have more than one status to report */
408 ps = jp->ps;
409 st = ps->status;
410 do {
411 int st1 = ps->status;
412 if (st1 != st)
413 /* yes - need multi-line output */
414 mode |= SHOW_MULTILINE;
415 if (st1 == -1 || !(mode & SHOW_SIGNALLED) || WIFEXITED(st1))
416 continue;
417 if (WIFSTOPPED(st1) || ((st1 = WTERMSIG(st1) & 0x7f)
418 && st1 != SIGINT && st1 != SIGPIPE))
419 mode |= SHOW_ISSIG;
420
421 } while (ps++, --procno);
422 procno = jp->nprocs;
423 }
424
425 if (mode & SHOW_SIGNALLED && !(mode & SHOW_ISSIG)) {
426 if (jp->state == JOBDONE && !(mode & SHOW_NO_FREE)) {
427 TRACE(("showjob: freeing job %d\n", jp - jobtab + 1));
428 freejob(jp);
429 }
430 return;
431 }
432
433 for (ps = jp->ps; --procno >= 0; ps++) { /* for each process */
434 if (ps == jp->ps)
435 fmtstr(s, 16, "[%ld] %c ",
436 (long)(jp - jobtab + 1),
437 #if JOBS
438 jp == jobtab + curjob ? '+' :
439 curjob != -1 && jp == jobtab +
440 jobtab[curjob].prev_job ? '-' :
441 #endif
442 ' ');
443 else
444 fmtstr(s, 16, " " );
445 col = strlen(s);
446 if (mode & SHOW_PID) {
447 fmtstr(s + col, 16, "%ld ", (long)ps->pid);
448 col += strlen(s + col);
449 }
450 if (ps->status == -1) {
451 scopy("Running", s + col);
452 } else if (WIFEXITED(ps->status)) {
453 st = WEXITSTATUS(ps->status);
454 if (st)
455 fmtstr(s + col, 16, "Done(%d)", st);
456 else
457 fmtstr(s + col, 16, "Done");
458 } else {
459 #if JOBS
460 if (WIFSTOPPED(ps->status))
461 st = WSTOPSIG(ps->status);
462 else /* WIFSIGNALED(ps->status) */
463 #endif
464 st = WTERMSIG(ps->status);
465 st &= 0x7f;
466 if (st < NSIG && sys_siglist[st])
467 scopyn(sys_siglist[st], s + col, 32);
468 else
469 fmtstr(s + col, 16, "Signal %d", st);
470 if (WCOREDUMP(ps->status)) {
471 col += strlen(s + col);
472 scopyn(" (core dumped)", s + col, 64 - col);
473 }
474 }
475 col += strlen(s + col);
476 outstr(s, out);
477 do {
478 outc(' ', out);
479 col++;
480 } while (col < 30);
481 outstr(ps->cmd, out);
482 if (mode & SHOW_MULTILINE) {
483 if (procno > 0) {
484 outc(' ', out);
485 outc('|', out);
486 }
487 } else {
488 while (--procno >= 0)
489 outfmt(out, " | %s", (++ps)->cmd );
490 }
491 outc('\n', out);
492 }
493 flushout(out);
494 jp->changed = 0;
495 if (jp->state == JOBDONE && !(mode & SHOW_NO_FREE))
496 freejob(jp);
497 }
498
499
500 int
jobscmd(int argc,char ** argv)501 jobscmd(int argc, char **argv)
502 {
503 int mode, m;
504 int sv = jobs_invalid;
505
506 jobs_invalid = 0;
507 mode = 0;
508 while ((m = nextopt("lp")))
509 if (m == 'l')
510 mode = SHOW_PID;
511 else
512 mode = SHOW_PGID;
513 if (*argptr)
514 do
515 showjob(out1, getjob(*argptr,0), mode);
516 while (*++argptr);
517 else
518 showjobs(out1, mode);
519 jobs_invalid = sv;
520 return 0;
521 }
522
523
524 /*
525 * Print a list of jobs. If "change" is nonzero, only print jobs whose
526 * statuses have changed since the last call to showjobs.
527 *
528 * If the shell is interrupted in the process of creating a job, the
529 * result may be a job structure containing zero processes. Such structures
530 * will be freed here.
531 */
532
533 void
showjobs(struct output * out,int mode)534 showjobs(struct output *out, int mode)
535 {
536 int jobno;
537 struct job *jp;
538 int silent = 0, gotpid;
539
540 TRACE(("showjobs(%x) called\n", mode));
541
542 /* If not even one one job changed, there is nothing to do */
543 gotpid = dowait(0, NULL);
544 while (dowait(0, NULL) > 0)
545 continue;
546 #ifdef JOBS
547 /*
548 * Check if we are not in our foreground group, and if not
549 * put us in it.
550 */
551 if (mflag && gotpid != -1 && tcgetpgrp(ttyfd) != getpid()) {
552 if (tcsetpgrp(ttyfd, getpid()) == -1)
553 error("Cannot set tty process group (%s) at %d",
554 strerror(errno), __LINE__);
555 TRACE(("repaired tty process group\n"));
556 silent = 1;
557 }
558 #endif
559 if (jobs_invalid)
560 return;
561
562 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
563 if (!jp->used)
564 continue;
565 if (jp->nprocs == 0) {
566 freejob(jp);
567 continue;
568 }
569 if ((mode & SHOW_CHANGED) && !jp->changed)
570 continue;
571 if (silent && jp->changed) {
572 jp->changed = 0;
573 continue;
574 }
575 showjob(out, jp, mode);
576 }
577 }
578
579 /*
580 * Mark a job structure as unused.
581 */
582
583 STATIC void
freejob(struct job * jp)584 freejob(struct job *jp)
585 {
586 INTOFF;
587 if (jp->ps != &jp->ps0) {
588 ckfree(jp->ps);
589 jp->ps = &jp->ps0;
590 }
591 jp->nprocs = 0;
592 jp->used = 0;
593 #if JOBS
594 set_curjob(jp, 0);
595 #endif
596 INTON;
597 }
598
599
600
601 int
waitcmd(int argc,char ** argv)602 waitcmd(int argc, char **argv)
603 {
604 struct job *job;
605 int status, retval = 127;
606 struct job *jp;
607
608 nextopt("");
609
610 if (!*argptr) {
611 /* wait for all jobs */
612 jp = jobtab;
613 if (jobs_invalid)
614 return 0;
615 for (;;) {
616 if (jp >= jobtab + njobs) {
617 /* no running procs */
618 return 0;
619 }
620 if (!jp->used || jp->state != JOBRUNNING) {
621 jp++;
622 continue;
623 }
624 if (dowait(1, (struct job *)NULL) == -1)
625 return 128 + SIGINT;
626 jp = jobtab;
627 }
628 }
629
630 for (; *argptr; argptr++) {
631 job = getjob(*argptr, 1);
632 if (!job) {
633 retval = 127;
634 continue;
635 }
636 /* loop until process terminated or stopped */
637 while (job->state == JOBRUNNING) {
638 if (dowait(1, (struct job *)NULL) == -1)
639 return 128 + SIGINT;
640 }
641 status = job->ps[job->nprocs].status;
642 if (WIFEXITED(status))
643 retval = WEXITSTATUS(status);
644 #if JOBS
645 else if (WIFSTOPPED(status))
646 retval = WSTOPSIG(status) + 128;
647 #endif
648 else {
649 /* XXX: limits number of signals */
650 retval = WTERMSIG(status) + 128;
651 }
652 if (!iflag)
653 freejob(job);
654 }
655 return retval;
656 }
657
658
659
660 int
jobidcmd(int argc,char ** argv)661 jobidcmd(int argc, char **argv)
662 {
663 struct job *jp;
664 int i;
665
666 nextopt("");
667 jp = getjob(*argptr, 0);
668 for (i = 0 ; i < jp->nprocs ; ) {
669 out1fmt("%ld", (long)jp->ps[i].pid);
670 out1c(++i < jp->nprocs ? ' ' : '\n');
671 }
672 return 0;
673 }
674
675 int
getjobpgrp(const char * name)676 getjobpgrp(const char *name)
677 {
678 struct job *jp;
679
680 jp = getjob(name, 1);
681 if (jp == 0)
682 return 0;
683 return -jp->ps[0].pid;
684 }
685
686 /*
687 * Convert a job name to a job structure.
688 */
689
690 STATIC struct job *
getjob(const char * name,int noerror)691 getjob(const char *name, int noerror)
692 {
693 int jobno = -1;
694 struct job *jp;
695 int pid;
696 int i;
697 const char *err_msg = "No such job: %s";
698
699 if (name == NULL) {
700 #if JOBS
701 jobno = curjob;
702 #endif
703 err_msg = "No current job";
704 } else if (name[0] == '%') {
705 if (is_number(name + 1)) {
706 jobno = number(name + 1) - 1;
707 } else if (!name[2]) {
708 switch (name[1]) {
709 #if JOBS
710 case 0:
711 case '+':
712 case '%':
713 jobno = curjob;
714 err_msg = "No current job";
715 break;
716 case '-':
717 jobno = curjob;
718 if (jobno != -1)
719 jobno = jobtab[jobno].prev_job;
720 err_msg = "No previous job";
721 break;
722 #endif
723 default:
724 goto check_pattern;
725 }
726 } else {
727 struct job *found;
728 check_pattern:
729 found = NULL;
730 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
731 if (!jp->used || jp->nprocs <= 0)
732 continue;
733 if ((name[1] == '?'
734 && strstr(jp->ps[0].cmd, name + 2))
735 || prefix(name + 1, jp->ps[0].cmd)) {
736 if (found) {
737 err_msg = "%s: ambiguous";
738 found = 0;
739 break;
740 }
741 found = jp;
742 }
743 }
744 if (found)
745 return found;
746 }
747
748 } else if (is_number(name)) {
749 pid = number(name);
750 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
751 if (jp->used && jp->nprocs > 0
752 && jp->ps[jp->nprocs - 1].pid == pid)
753 return jp;
754 }
755 }
756
757 if (!jobs_invalid && jobno >= 0 && jobno < njobs) {
758 jp = jobtab + jobno;
759 if (jp->used)
760 return jp;
761 }
762 if (!noerror)
763 error(err_msg, name);
764 return 0;
765 }
766
767
768
769 /*
770 * Return a new job structure,
771 */
772
773 struct job *
makejob(union node * node,int nprocs)774 makejob(union node *node, int nprocs)
775 {
776 int i;
777 struct job *jp;
778
779 if (jobs_invalid) {
780 for (i = njobs, jp = jobtab ; --i >= 0 ; jp++) {
781 if (jp->used)
782 freejob(jp);
783 }
784 jobs_invalid = 0;
785 }
786
787 for (i = njobs, jp = jobtab ; ; jp++) {
788 if (--i < 0) {
789 INTOFF;
790 if (njobs == 0) {
791 jobtab = ckmalloc(4 * sizeof jobtab[0]);
792 } else {
793 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
794 memcpy(jp, jobtab, njobs * sizeof jp[0]);
795 /* Relocate `ps' pointers */
796 for (i = 0; i < njobs; i++)
797 if (jp[i].ps == &jobtab[i].ps0)
798 jp[i].ps = &jp[i].ps0;
799 ckfree(jobtab);
800 jobtab = jp;
801 }
802 jp = jobtab + njobs;
803 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0);
804 INTON;
805 break;
806 }
807 if (jp->used == 0)
808 break;
809 }
810 INTOFF;
811 jp->state = JOBRUNNING;
812 jp->used = 1;
813 jp->changed = 0;
814 jp->nprocs = 0;
815 #if JOBS
816 jp->jobctl = jobctl;
817 set_curjob(jp, 1);
818 #endif
819 if (nprocs > 1) {
820 jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
821 } else {
822 jp->ps = &jp->ps0;
823 }
824 INTON;
825 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs,
826 jp - jobtab + 1));
827 return jp;
828 }
829
830
831 /*
832 * Fork off a subshell. If we are doing job control, give the subshell its
833 * own process group. Jp is a job structure that the job is to be added to.
834 * N is the command that will be evaluated by the child. Both jp and n may
835 * be NULL. The mode parameter can be one of the following:
836 * FORK_FG - Fork off a foreground process.
837 * FORK_BG - Fork off a background process.
838 * FORK_NOJOB - Like FORK_FG, but don't give the process its own
839 * process group even if job control is on.
840 *
841 * When job control is turned off, background processes have their standard
842 * input redirected to /dev/null (except for the second and later processes
843 * in a pipeline).
844 */
845
846 int
forkshell(struct job * jp,union node * n,int mode)847 forkshell(struct job *jp, union node *n, int mode)
848 {
849 int pid;
850
851 TRACE(("forkshell(%%%d, %p, %d) called\n", jp - jobtab, n, mode));
852 switch ((pid = fork())) {
853 case -1:
854 TRACE(("Fork failed, errno=%d\n", errno));
855 INTON;
856 error("Cannot fork");
857 break;
858 case 0:
859 forkchild(jp, n, mode, 0);
860 return 0;
861 default:
862 return forkparent(jp, n, mode, pid);
863 }
864 }
865
866 int
forkparent(struct job * jp,union node * n,int mode,pid_t pid)867 forkparent(struct job *jp, union node *n, int mode, pid_t pid)
868 {
869 int pgrp;
870
871 if (rootshell && mode != FORK_NOJOB && mflag) {
872 if (jp == NULL || jp->nprocs == 0)
873 pgrp = pid;
874 else
875 pgrp = jp->ps[0].pid;
876 #ifdef USE_PROCESS_GROUPS
877 /* This can fail because we are doing it in the child also */
878 (void)setpgid(pid, pgrp);
879 #endif
880 }
881 if (mode == FORK_BG)
882 backgndpid = pid; /* set $! */
883 if (jp) {
884 struct procstat *ps = &jp->ps[jp->nprocs++];
885 ps->pid = pid;
886 ps->status = -1;
887 ps->cmd[0] = 0;
888 if (/* iflag && rootshell && */ n)
889 commandtext(ps, n);
890 }
891 TRACE(("In parent shell: child = %d\n", pid));
892 return pid;
893 }
894
895 void
forkchild(struct job * jp,union node * n,int mode,int vforked)896 forkchild(struct job *jp, union node *n, int mode, int vforked)
897 {
898 int wasroot;
899 int pgrp;
900 const char *devnull = _PATH_DEVNULL;
901 const char *nullerr = "Can't open %s";
902
903 wasroot = rootshell;
904 TRACE(("Child shell %d\n", getpid()));
905 if (!vforked)
906 rootshell = 0;
907
908 closescript(vforked);
909 clear_traps(vforked);
910 #if JOBS
911 if (!vforked)
912 jobctl = 0; /* do job control only in root shell */
913 if (wasroot && mode != FORK_NOJOB && mflag) {
914 if (jp == NULL || jp->nprocs == 0)
915 pgrp = getpid();
916 else
917 pgrp = jp->ps[0].pid;
918 #ifdef USE_PROCESS_GROUPS
919 /* This can fail because we are doing it in the parent also */
920 (void)setpgid(0, pgrp);
921 if (mode == FORK_FG) {
922 if (tcsetpgrp(ttyfd, pgrp) == -1)
923 error("Cannot set tty process group (%s) at %d",
924 strerror(errno), __LINE__);
925 }
926 #endif
927 setsignal(SIGTSTP, vforked);
928 setsignal(SIGTTOU, vforked);
929 } else if (mode == FORK_BG) {
930 ignoresig(SIGINT, vforked);
931 ignoresig(SIGQUIT, vforked);
932 if ((jp == NULL || jp->nprocs == 0) &&
933 ! fd0_redirected_p ()) {
934 close(0);
935 if (open(devnull, O_RDONLY) != 0)
936 error(nullerr, devnull);
937 }
938 }
939 #else
940 if (mode == FORK_BG) {
941 ignoresig(SIGINT, vforked);
942 ignoresig(SIGQUIT, vforked);
943 if ((jp == NULL || jp->nprocs == 0) &&
944 ! fd0_redirected_p ()) {
945 close(0);
946 if (open(devnull, O_RDONLY) != 0)
947 error(nullerr, devnull);
948 }
949 }
950 #endif
951 if (wasroot && iflag) {
952 setsignal(SIGINT, vforked);
953 setsignal(SIGQUIT, vforked);
954 setsignal(SIGTERM, vforked);
955 }
956
957 if (!vforked)
958 jobs_invalid = 1;
959 }
960
961 /*
962 * Wait for job to finish.
963 *
964 * Under job control we have the problem that while a child process is
965 * running interrupts generated by the user are sent to the child but not
966 * to the shell. This means that an infinite loop started by an inter-
967 * active user may be hard to kill. With job control turned off, an
968 * interactive user may place an interactive program inside a loop. If
969 * the interactive program catches interrupts, the user doesn't want
970 * these interrupts to also abort the loop. The approach we take here
971 * is to have the shell ignore interrupt signals while waiting for a
972 * forground process to terminate, and then send itself an interrupt
973 * signal if the child process was terminated by an interrupt signal.
974 * Unfortunately, some programs want to do a bit of cleanup and then
975 * exit on interrupt; unless these processes terminate themselves by
976 * sending a signal to themselves (instead of calling exit) they will
977 * confuse this approach.
978 */
979
980 int
waitforjob(struct job * jp)981 waitforjob(struct job *jp)
982 {
983 #if JOBS
984 int mypgrp = getpgrp();
985 #endif
986 int status;
987 int st;
988
989 INTOFF;
990 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1));
991 while (jp->state == JOBRUNNING) {
992 dowait(1, jp);
993 }
994 #if JOBS
995 if (jp->jobctl) {
996 if (tcsetpgrp(ttyfd, mypgrp) == -1)
997 error("Cannot set tty process group (%s) at %d",
998 strerror(errno), __LINE__);
999 }
1000 if (jp->state == JOBSTOPPED && curjob != jp - jobtab)
1001 set_curjob(jp, 2);
1002 #endif
1003 status = jp->ps[jp->nprocs - 1].status;
1004 /* convert to 8 bits */
1005 if (WIFEXITED(status))
1006 st = WEXITSTATUS(status);
1007 #if JOBS
1008 else if (WIFSTOPPED(status))
1009 st = WSTOPSIG(status) + 128;
1010 #endif
1011 else
1012 st = WTERMSIG(status) + 128;
1013 TRACE(("waitforjob: job %d, nproc %d, status %x, st %x\n",
1014 jp - jobtab + 1, jp->nprocs, status, st ));
1015 #if JOBS
1016 if (jp->jobctl) {
1017 /*
1018 * This is truly gross.
1019 * If we're doing job control, then we did a TIOCSPGRP which
1020 * caused us (the shell) to no longer be in the controlling
1021 * session -- so we wouldn't have seen any ^C/SIGINT. So, we
1022 * intuit from the subprocess exit status whether a SIGINT
1023 * occurred, and if so interrupt ourselves. Yuck. - mycroft
1024 */
1025 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1026 raise(SIGINT);
1027 }
1028 #endif
1029 if (! JOBS || jp->state == JOBDONE)
1030 freejob(jp);
1031 INTON;
1032 return st;
1033 }
1034
1035
1036
1037 /*
1038 * Wait for a process to terminate.
1039 */
1040
1041 STATIC int
dowait(int block,struct job * job)1042 dowait(int block, struct job *job)
1043 {
1044 int pid;
1045 int status;
1046 struct procstat *sp;
1047 struct job *jp;
1048 struct job *thisjob;
1049 int done;
1050 int stopped;
1051 extern volatile char gotsig[];
1052
1053 TRACE(("dowait(%d) called\n", block));
1054 do {
1055 pid = waitproc(block, job, &status);
1056 TRACE(("wait returns pid %d, status %d\n", pid, status));
1057 } while (pid == -1 && errno == EINTR && gotsig[SIGINT - 1] == 0);
1058 if (pid <= 0)
1059 return pid;
1060 INTOFF;
1061 thisjob = NULL;
1062 for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1063 if (jp->used) {
1064 done = 1;
1065 stopped = 1;
1066 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1067 if (sp->pid == -1)
1068 continue;
1069 if (sp->pid == pid) {
1070 TRACE(("Job %d: changing status of proc %d from 0x%x to 0x%x\n", jp - jobtab + 1, pid, sp->status, status));
1071 sp->status = status;
1072 thisjob = jp;
1073 }
1074 if (sp->status == -1)
1075 stopped = 0;
1076 else if (WIFSTOPPED(sp->status))
1077 done = 0;
1078 }
1079 if (stopped) { /* stopped or done */
1080 int state = done ? JOBDONE : JOBSTOPPED;
1081 if (jp->state != state) {
1082 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1083 jp->state = state;
1084 #if JOBS
1085 if (done)
1086 set_curjob(jp, 0);
1087 #endif
1088 }
1089 }
1090 }
1091 }
1092
1093 if (thisjob && thisjob->state != JOBRUNNING) {
1094 int mode = 0;
1095 if (!rootshell || !iflag)
1096 mode = SHOW_SIGNALLED;
1097 if (job == thisjob)
1098 mode = SHOW_SIGNALLED | SHOW_NO_FREE;
1099 if (mode)
1100 showjob(out2, thisjob, mode);
1101 else {
1102 TRACE(("Not printing status, rootshell=%d, job=%p\n",
1103 rootshell, job));
1104 thisjob->changed = 1;
1105 }
1106 }
1107
1108 INTON;
1109 return pid;
1110 }
1111
1112
1113
1114 /*
1115 * Do a wait system call. If job control is compiled in, we accept
1116 * stopped processes. If block is zero, we return a value of zero
1117 * rather than blocking.
1118 *
1119 * System V doesn't have a non-blocking wait system call. It does
1120 * have a SIGCLD signal that is sent to a process when one of it's
1121 * children dies. The obvious way to use SIGCLD would be to install
1122 * a handler for SIGCLD which simply bumped a counter when a SIGCLD
1123 * was received, and have waitproc bump another counter when it got
1124 * the status of a process. Waitproc would then know that a wait
1125 * system call would not block if the two counters were different.
1126 * This approach doesn't work because if a process has children that
1127 * have not been waited for, System V will send it a SIGCLD when it
1128 * installs a signal handler for SIGCLD. What this means is that when
1129 * a child exits, the shell will be sent SIGCLD signals continuously
1130 * until is runs out of stack space, unless it does a wait call before
1131 * restoring the signal handler. The code below takes advantage of
1132 * this (mis)feature by installing a signal handler for SIGCLD and
1133 * then checking to see whether it was called. If there are any
1134 * children to be waited for, it will be.
1135 *
1136 * If neither SYSV nor BSD is defined, we don't implement nonblocking
1137 * waits at all. In this case, the user will not be informed when
1138 * a background process until the next time she runs a real program
1139 * (as opposed to running a builtin command or just typing return),
1140 * and the jobs command may give out of date information.
1141 */
1142
1143 #ifdef SYSV
1144 STATIC int gotsigchild;
1145
onsigchild()1146 STATIC int onsigchild() {
1147 gotsigchild = 1;
1148 }
1149 #endif
1150
1151
1152 STATIC int
waitproc(int block,struct job * jp,int * status)1153 waitproc(int block, struct job *jp, int *status)
1154 {
1155 #ifdef BSD
1156 int flags = 0;
1157
1158 #if JOBS
1159 if (jp != NULL && jp->jobctl)
1160 flags |= WUNTRACED;
1161 #endif
1162 if (block == 0)
1163 flags |= WNOHANG;
1164 return wait3(status, flags, (struct rusage *)NULL);
1165 #else
1166 #ifdef SYSV
1167 int (*save)();
1168
1169 if (block == 0) {
1170 gotsigchild = 0;
1171 save = signal(SIGCLD, onsigchild);
1172 signal(SIGCLD, save);
1173 if (gotsigchild == 0)
1174 return 0;
1175 }
1176 return wait(status);
1177 #else
1178 if (block == 0)
1179 return 0;
1180 return wait(status);
1181 #endif
1182 #endif
1183 }
1184
1185 /*
1186 * return 1 if there are stopped jobs, otherwise 0
1187 */
1188 int job_warning = 0;
1189 int
stoppedjobs(void)1190 stoppedjobs(void)
1191 {
1192 int jobno;
1193 struct job *jp;
1194
1195 if (job_warning || jobs_invalid)
1196 return (0);
1197 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1198 if (jp->used == 0)
1199 continue;
1200 if (jp->state == JOBSTOPPED) {
1201 out2str("You have stopped jobs.\n");
1202 job_warning = 2;
1203 return (1);
1204 }
1205 }
1206
1207 return (0);
1208 }
1209
1210 /*
1211 * Return a string identifying a command (to be printed by the
1212 * jobs command).
1213 */
1214
1215 STATIC char *cmdnextc;
1216 STATIC int cmdnleft;
1217
1218 void
commandtext(struct procstat * ps,union node * n)1219 commandtext(struct procstat *ps, union node *n)
1220 {
1221 int len;
1222
1223 cmdnextc = ps->cmd;
1224 if (iflag || mflag || sizeof ps->cmd < 100)
1225 len = sizeof(ps->cmd);
1226 else
1227 len = sizeof(ps->cmd) / 10;
1228 cmdnleft = len;
1229 cmdtxt(n);
1230 if (cmdnleft <= 0) {
1231 char *p = ps->cmd + len - 4;
1232 p[0] = '.';
1233 p[1] = '.';
1234 p[2] = '.';
1235 p[3] = 0;
1236 } else
1237 *cmdnextc = '\0';
1238 TRACE(("commandtext: ps->cmd %x, end %x, left %d\n\t\"%s\"\n",
1239 ps->cmd, cmdnextc, cmdnleft, ps->cmd));
1240 }
1241
1242
1243 STATIC void
cmdtxt(union node * n)1244 cmdtxt(union node *n)
1245 {
1246 union node *np;
1247 struct nodelist *lp;
1248 const char *p;
1249 int i;
1250 char s[2];
1251
1252 if (n == NULL || cmdnleft <= 0)
1253 return;
1254 switch (n->type) {
1255 case NSEMI:
1256 cmdtxt(n->nbinary.ch1);
1257 cmdputs("; ");
1258 cmdtxt(n->nbinary.ch2);
1259 break;
1260 case NAND:
1261 cmdtxt(n->nbinary.ch1);
1262 cmdputs(" && ");
1263 cmdtxt(n->nbinary.ch2);
1264 break;
1265 case NOR:
1266 cmdtxt(n->nbinary.ch1);
1267 cmdputs(" || ");
1268 cmdtxt(n->nbinary.ch2);
1269 break;
1270 case NPIPE:
1271 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1272 cmdtxt(lp->n);
1273 if (lp->next)
1274 cmdputs(" | ");
1275 }
1276 break;
1277 case NSUBSHELL:
1278 cmdputs("(");
1279 cmdtxt(n->nredir.n);
1280 cmdputs(")");
1281 break;
1282 case NREDIR:
1283 case NBACKGND:
1284 cmdtxt(n->nredir.n);
1285 break;
1286 case NIF:
1287 cmdputs("if ");
1288 cmdtxt(n->nif.test);
1289 cmdputs("; then ");
1290 cmdtxt(n->nif.ifpart);
1291 if (n->nif.elsepart) {
1292 cmdputs("; else ");
1293 cmdtxt(n->nif.elsepart);
1294 }
1295 cmdputs("; fi");
1296 break;
1297 case NWHILE:
1298 cmdputs("while ");
1299 goto until;
1300 case NUNTIL:
1301 cmdputs("until ");
1302 until:
1303 cmdtxt(n->nbinary.ch1);
1304 cmdputs("; do ");
1305 cmdtxt(n->nbinary.ch2);
1306 cmdputs("; done");
1307 break;
1308 case NFOR:
1309 cmdputs("for ");
1310 cmdputs(n->nfor.var);
1311 cmdputs(" in ");
1312 cmdlist(n->nfor.args, 1);
1313 cmdputs("; do ");
1314 cmdtxt(n->nfor.body);
1315 cmdputs("; done");
1316 break;
1317 case NCASE:
1318 cmdputs("case ");
1319 cmdputs(n->ncase.expr->narg.text);
1320 cmdputs(" in ");
1321 for (np = n->ncase.cases; np; np = np->nclist.next) {
1322 cmdtxt(np->nclist.pattern);
1323 cmdputs(") ");
1324 cmdtxt(np->nclist.body);
1325 cmdputs(";; ");
1326 }
1327 cmdputs("esac");
1328 break;
1329 case NDEFUN:
1330 cmdputs(n->narg.text);
1331 cmdputs("() { ... }");
1332 break;
1333 case NCMD:
1334 cmdlist(n->ncmd.args, 1);
1335 cmdlist(n->ncmd.redirect, 0);
1336 break;
1337 case NARG:
1338 cmdputs(n->narg.text);
1339 break;
1340 case NTO:
1341 p = ">"; i = 1; goto redir;
1342 case NCLOBBER:
1343 p = ">|"; i = 1; goto redir;
1344 case NAPPEND:
1345 p = ">>"; i = 1; goto redir;
1346 case NTOFD:
1347 p = ">&"; i = 1; goto redir;
1348 case NFROM:
1349 p = "<"; i = 0; goto redir;
1350 case NFROMFD:
1351 p = "<&"; i = 0; goto redir;
1352 case NFROMTO:
1353 p = "<>"; i = 0; goto redir;
1354 redir:
1355 if (n->nfile.fd != i) {
1356 s[0] = n->nfile.fd + '0';
1357 s[1] = '\0';
1358 cmdputs(s);
1359 }
1360 cmdputs(p);
1361 if (n->type == NTOFD || n->type == NFROMFD) {
1362 s[0] = n->ndup.dupfd + '0';
1363 s[1] = '\0';
1364 cmdputs(s);
1365 } else {
1366 cmdtxt(n->nfile.fname);
1367 }
1368 break;
1369 case NHERE:
1370 case NXHERE:
1371 cmdputs("<<...");
1372 break;
1373 default:
1374 cmdputs("???");
1375 break;
1376 }
1377 }
1378
1379 STATIC void
cmdlist(union node * np,int sep)1380 cmdlist(union node *np, int sep)
1381 {
1382 for (; np; np = np->narg.next) {
1383 if (!sep)
1384 cmdputs(" ");
1385 cmdtxt(np);
1386 if (sep && np->narg.next)
1387 cmdputs(" ");
1388 }
1389 }
1390
1391
1392 STATIC void
cmdputs(const char * s)1393 cmdputs(const char *s)
1394 {
1395 const char *p, *str = 0;
1396 char c, cc[2] = " ";
1397 char *nextc;
1398 int nleft;
1399 int subtype = 0;
1400 int quoted = 0;
1401 static char vstype[16][4] = { "", "}", "-", "+", "?", "=",
1402 "#", "##", "%", "%%" };
1403
1404 p = s;
1405 nextc = cmdnextc;
1406 nleft = cmdnleft;
1407 while (nleft > 0 && (c = *p++) != 0) {
1408 switch (c) {
1409 case CTLESC:
1410 c = *p++;
1411 break;
1412 case CTLVAR:
1413 subtype = *p++;
1414 if ((subtype & VSTYPE) == VSLENGTH)
1415 str = "${#";
1416 else
1417 str = "${";
1418 if (!(subtype & VSQUOTE) != !(quoted & 1)) {
1419 quoted ^= 1;
1420 c = '"';
1421 } else
1422 c = *str++;
1423 break;
1424 case CTLENDVAR:
1425 if (quoted & 1) {
1426 c = '"';
1427 str = "}";
1428 } else
1429 c = '}';
1430 quoted >>= 1;
1431 subtype = 0;
1432 break;
1433 case CTLBACKQ:
1434 c = '$';
1435 str = "(...)";
1436 break;
1437 case CTLBACKQ+CTLQUOTE:
1438 c = '"';
1439 str = "$(...)\"";
1440 break;
1441 case CTLARI:
1442 c = '$';
1443 str = "((";
1444 break;
1445 case CTLENDARI:
1446 c = ')';
1447 str = ")";
1448 break;
1449 case CTLQUOTEMARK:
1450 quoted ^= 1;
1451 c = '"';
1452 break;
1453 case '=':
1454 if (subtype == 0)
1455 break;
1456 str = vstype[subtype & VSTYPE];
1457 if (subtype & VSNUL)
1458 c = ':';
1459 else
1460 c = *str++;
1461 if (c != '}')
1462 quoted <<= 1;
1463 break;
1464 case '\'':
1465 case '\\':
1466 case '"':
1467 case '$':
1468 /* These can only happen inside quotes */
1469 cc[0] = c;
1470 str = cc;
1471 c = '\\';
1472 break;
1473 default:
1474 break;
1475 }
1476 do {
1477 *nextc++ = c;
1478 } while (--nleft > 0 && str && (c = *str++));
1479 str = 0;
1480 }
1481 if ((quoted & 1) && nleft) {
1482 *nextc++ = '"';
1483 nleft--;
1484 }
1485 cmdnleft = nleft;
1486 cmdnextc = nextc;
1487 }
1488