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