xref: /netbsd-src/bin/csh/proc.c (revision 53d1339bf7f9c7367b35a9e1ebe693f9b047a47b)
1 /* $NetBSD: proc.c,v 1.40 2020/08/09 00:22:53 dholland Exp $ */
2 
3 /*-
4  * Copyright (c) 1980, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)proc.c	8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: proc.c,v 1.40 2020/08/09 00:22:53 dholland Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/types.h>
42 #include <sys/wait.h>
43 
44 #include <errno.h>
45 #include <stdarg.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #include "csh.h"
51 #include "dir.h"
52 #include "extern.h"
53 #include "proc.h"
54 
55 #define BIGINDEX 9 /* largest desirable job index */
56 
57 extern int insource;
58 
59 struct process proclist;
60 int pnoprocesses;
61 
62 struct process *pholdjob;
63 
64 struct process *pcurrjob;
65 struct process *pcurrent;
66 struct process *pprevious;
67 
68 int pmaxindex;
69 
70 static void pflushall(void);
71 static void pflush(struct process *);
72 static void pclrcurr(struct process *);
73 static void padd(struct command *);
74 static int pprint(struct process *, int);
75 static void ptprint(struct process *);
76 static void pads(Char *);
77 static void pkill(Char **v, int);
78 static struct process *pgetcurr(struct process *);
79 static void okpcntl(void);
80 
81 /*
82  * pchild - called at interrupt level by the SIGCHLD signal
83  *	indicating that at least one child has terminated or stopped
84  *	thus at least one wait system call will definitely return a
85  *	childs status.  Top level routines (like pwait) must be sure
86  *	to mask interrupts when playing with the proclist data structures!
87  */
88 /* ARGSUSED */
89 void
90 pchild(int notused)
91 {
92     struct rusage ru;
93     struct process *fp, *pp;
94     int jobflags, pid, w;
95 
96 loop:
97     errno = 0;			/* reset, just in case */
98     pid = wait3(&w,
99        (setintr && (intty || insource) ? WNOHANG | WUNTRACED : WNOHANG), &ru);
100 
101     if (pid <= 0) {
102 	if (errno == EINTR) {
103 	    errno = 0;
104 	    goto loop;
105 	}
106 	pnoprocesses = pid == -1;
107 	return;
108     }
109     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
110 	if (pid == pp->p_pid)
111 	    goto found;
112     goto loop;
113 found:
114     if (pid == atoi(short2str(value(STRchild))))
115 	unsetv(STRchild);
116     pp->p_flags &= ~(PRUNNING | PSTOPPED | PREPORTED);
117     if (WIFSTOPPED(w)) {
118 	pp->p_flags |= PSTOPPED;
119 	pp->p_reason = WSTOPSIG(w);
120     }
121     else {
122 	if (pp->p_flags & (PTIME | PPTIME) || adrof(STRtime))
123 	    (void)clock_gettime(CLOCK_MONOTONIC, &pp->p_etime);
124 
125 	pp->p_rusage = ru;
126 	if (WIFSIGNALED(w)) {
127 	    if (WTERMSIG(w) == SIGINT)
128 		pp->p_flags |= PINTERRUPTED;
129 	    else
130 		pp->p_flags |= PSIGNALED;
131 	    if (WCOREDUMP(w))
132 		pp->p_flags |= PDUMPED;
133 	    pp->p_reason = WTERMSIG(w);
134 	}
135 	else {
136 	    pp->p_reason = WEXITSTATUS(w);
137 	    if (pp->p_reason != 0)
138 		pp->p_flags |= PAEXITED;
139 	    else
140 		pp->p_flags |= PNEXITED;
141 	}
142     }
143     jobflags = 0;
144     fp = pp;
145     do {
146 	if ((fp->p_flags & (PPTIME | PRUNNING | PSTOPPED)) == 0 &&
147 	    !child && adrof(STRtime) &&
148 	    fp->p_rusage.ru_utime.tv_sec + fp->p_rusage.ru_stime.tv_sec
149 	    >= atoi(short2str(value(STRtime))))
150 	    fp->p_flags |= PTIME;
151 	jobflags |= fp->p_flags;
152     } while ((fp = fp->p_friends) != pp);
153     pp->p_flags &= ~PFOREGND;
154     if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
155 	pp->p_flags &= ~PPTIME;
156 	pp->p_flags |= PTIME;
157     }
158     if ((jobflags & (PRUNNING | PREPORTED)) == 0) {
159 	fp = pp;
160 	do {
161 	    if (fp->p_flags & PSTOPPED)
162 		fp->p_flags |= PREPORTED;
163 	} while ((fp = fp->p_friends) != pp);
164 	while (fp->p_pid != fp->p_jobid)
165 	    fp = fp->p_friends;
166 	if (jobflags & PSTOPPED) {
167 	    if (pcurrent && pcurrent != fp)
168 		pprevious = pcurrent;
169 	    pcurrent = fp;
170 	}
171 	else
172 	    pclrcurr(fp);
173 	if (jobflags & PFOREGND) {
174 	    if (jobflags & (PSIGNALED | PSTOPPED | PPTIME) ||
175 #ifdef IIASA
176 		jobflags & PAEXITED ||
177 #endif
178 		!eq(dcwd->di_name, fp->p_cwd->di_name)) {
179 		;		/* print in pjwait */
180 	    }
181 	    /* PWP: print a newline after ^C */
182 	    else if (jobflags & PINTERRUPTED) {
183 		(void)vis_fputc('\r' | QUOTE, cshout);
184 		(void)fputc('\n', cshout);
185 	    }
186 	}
187 	else {
188 	    if (jobflags & PNOTIFY || adrof(STRnotify)) {
189 		(void)vis_fputc('\r' | QUOTE, cshout);
190 		(void)fputc('\n', cshout);
191 		(void)pprint(pp, NUMBER | NAME | REASON);
192 		if ((jobflags & PSTOPPED) == 0)
193 		    pflush(pp);
194 	    }
195 	    else {
196 		fp->p_flags |= PNEEDNOTE;
197 		neednote++;
198 	    }
199 	}
200     }
201     goto loop;
202 }
203 
204 void
205 pnote(void)
206 {
207     struct process *pp;
208     sigset_t osigset, nsigset;
209     int flags;
210 
211     neednote = 0;
212     sigemptyset(&nsigset);
213     (void)sigaddset(&nsigset, SIGCHLD);
214     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next) {
215 	if (pp->p_flags & PNEEDNOTE) {
216 	    (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
217 	    pp->p_flags &= ~PNEEDNOTE;
218 	    flags = pprint(pp, NUMBER | NAME | REASON);
219 	    if ((flags & (PRUNNING | PSTOPPED)) == 0)
220 		pflush(pp);
221 	    (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
222 	}
223     }
224 }
225 
226 /*
227  * pwait - wait for current job to terminate, maintaining integrity
228  *	of current and previous job indicators.
229  */
230 void
231 pwait(void)
232 {
233     struct process *fp, *pp;
234     sigset_t osigset, nsigset;
235 
236     /*
237      * Here's where dead procs get flushed.
238      */
239     sigemptyset(&nsigset);
240     (void)sigaddset(&nsigset, SIGCHLD);
241     (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
242     for (pp = (fp = &proclist)->p_next; pp != NULL; pp = (fp = pp)->p_next)
243 	if (pp->p_pid == 0) {
244 	    fp->p_next = pp->p_next;
245 	    free(pp->p_command);
246 	    if (pp->p_cwd && --pp->p_cwd->di_count == 0)
247 		if (pp->p_cwd->di_next == 0)
248 		    dfree(pp->p_cwd);
249 	    free(pp);
250 	    pp = fp;
251 	}
252     (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
253     pjwait(pcurrjob);
254 }
255 
256 
257 /*
258  * pjwait - wait for a job to finish or become stopped
259  *	It is assumed to be in the foreground state (PFOREGND)
260  */
261 void
262 pjwait(struct process *pp)
263 {
264     struct process *fp;
265     sigset_t osigset, nsigset;
266     int jobflags, reason;
267 
268     while (pp->p_pid != pp->p_jobid)
269 	pp = pp->p_friends;
270     fp = pp;
271 
272     do {
273 	if ((fp->p_flags & (PFOREGND | PRUNNING)) == PRUNNING)
274 	    (void)fprintf(csherr, "BUG: waiting for background job!\n");
275     } while ((fp = fp->p_friends) != pp);
276     /*
277      * Now keep pausing as long as we are not interrupted (SIGINT), and the
278      * target process, or any of its friends, are running
279      */
280     fp = pp;
281     sigemptyset(&nsigset);
282     (void)sigaddset(&nsigset, SIGCHLD);
283     (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
284     for (;;) {
285 	sigemptyset(&nsigset);
286 	(void)sigaddset(&nsigset, SIGCHLD);
287 	(void)sigprocmask(SIG_BLOCK, &nsigset, NULL);
288 	jobflags = 0;
289 	do
290 	    jobflags |= fp->p_flags;
291 	while ((fp = (fp->p_friends)) != pp);
292 	if ((jobflags & PRUNNING) == 0)
293 	    break;
294 #ifdef JOBDEBUG
295 	(void)fprintf(csherr, "starting to sigsuspend for  SIGCHLD on %d\n",
296 		       fp->p_pid);
297 #endif				/* JOBDEBUG */
298 	nsigset = osigset;
299 	(void)sigdelset(&nsigset, SIGCHLD);
300 	(void)sigsuspend(&nsigset);
301     }
302     (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
303     if (tpgrp > 0)		/* get tty back */
304 	(void)tcsetpgrp(FSHTTY, tpgrp);
305     if ((jobflags & (PSIGNALED | PSTOPPED | PTIME)) ||
306 	!eq(dcwd->di_name, fp->p_cwd->di_name)) {
307 	if (jobflags & PSTOPPED) {
308 	    (void) fputc('\n', cshout);
309 	    if (adrof(STRlistjobs)) {
310 		Char *jobcommand[3];
311 
312 		jobcommand[0] = STRjobs;
313 		if (eq(value(STRlistjobs), STRlong))
314 		    jobcommand[1] = STRml;
315 		else
316 		    jobcommand[1] = NULL;
317 		jobcommand[2] = NULL;
318 
319 		dojobs(jobcommand, NULL);
320 		(void)pprint(pp, SHELLDIR);
321 	    }
322 	    else
323 		(void)pprint(pp, AREASON | SHELLDIR);
324 	}
325 	else
326 	    (void)pprint(pp, AREASON | SHELLDIR);
327     }
328     if ((jobflags & (PINTERRUPTED | PSTOPPED)) && setintr &&
329 	(!gointr || !eq(gointr, STRminus))) {
330 	if ((jobflags & PSTOPPED) == 0)
331 	    pflush(pp);
332 	pintr1(0);
333     }
334     reason = 0;
335     fp = pp;
336     do {
337 	if (fp->p_reason)
338 	    reason = fp->p_flags & (PSIGNALED | PINTERRUPTED) ?
339 		fp->p_reason | META : fp->p_reason;
340     } while ((fp = fp->p_friends) != pp);
341     if ((reason != 0) && (adrof(STRprintexitvalue))) {
342 	(void)fprintf(cshout, "Exit %d\n", reason);
343     }
344     set(STRstatus, putn(reason));
345     if (reason && exiterr)
346 	exitstat();
347     pflush(pp);
348 }
349 
350 /*
351  * dowait - wait for all processes to finish
352  */
353 void
354 /*ARGSUSED*/
355 dowait(Char **v, struct command *t)
356 {
357     struct process *pp;
358     sigset_t osigset, nsigset;
359 
360     pjobs++;
361     sigemptyset(&nsigset);
362     (void)sigaddset(&nsigset, SIGCHLD);
363     (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
364 loop:
365     for (pp = proclist.p_next; pp; pp = pp->p_next)
366 	if (pp->p_pid &&	/* pp->p_pid == pp->p_jobid && */
367 	    pp->p_flags & PRUNNING) {
368 	    sigemptyset(&nsigset);
369 	    (void)sigsuspend(&nsigset);
370 	    goto loop;
371 	}
372     (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
373     pjobs = 0;
374 }
375 
376 /*
377  * pflushall - flush all jobs from list (e.g. at fork())
378  */
379 static void
380 pflushall(void)
381 {
382     struct process *pp;
383 
384     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
385 	if (pp->p_pid)
386 	    pflush(pp);
387 }
388 
389 /*
390  * pflush - flag all process structures in the same job as the
391  *	the argument process for deletion.  The actual free of the
392  *	space is not done here since pflush is called at interrupt level.
393  */
394 static void
395 pflush(struct process *pp)
396 {
397     struct process *np;
398     int idx;
399 
400     if (pp->p_pid == 0) {
401 	(void)fprintf(csherr, "BUG: process flushed twice");
402 	return;
403     }
404     while (pp->p_pid != pp->p_jobid)
405 	pp = pp->p_friends;
406     pclrcurr(pp);
407     if (pp == pcurrjob)
408 	pcurrjob = 0;
409     idx = pp->p_index;
410     np = pp;
411     do {
412 	np->p_index = np->p_pid = 0;
413 	np->p_flags &= ~PNEEDNOTE;
414     } while ((np = np->p_friends) != pp);
415     if (idx == pmaxindex) {
416 	for (np = proclist.p_next, idx = 0; np; np = np->p_next)
417 	    if (np->p_index > idx)
418 		idx = np->p_index;
419 	pmaxindex = idx;
420     }
421 }
422 
423 /*
424  * pclrcurr - make sure the given job is not the current or previous job;
425  *	pp MUST be the job leader
426  */
427 static void
428 pclrcurr(struct process *pp)
429 {
430     if (pp == pcurrent) {
431 	if (pprevious != NULL) {
432 	    pcurrent = pprevious;
433 	    pprevious = pgetcurr(pp);
434 	}
435 	else {
436 	    pcurrent = pgetcurr(pp);
437 	    pprevious = pgetcurr(pp);
438 	}
439     } else if (pp == pprevious)
440 	pprevious = pgetcurr(pp);
441 }
442 
443 /* +4 here is 1 for '\0', 1 ea for << >& >> */
444 static Char command[PMAXLEN + 4];
445 static size_t cmdlen;
446 static Char *cmdp;
447 
448 /*
449  * palloc - allocate a process structure and fill it up.
450  *	an important assumption is made that the process is running.
451  */
452 void
453 palloc(int pid, struct command *t)
454 {
455     struct process *pp;
456     int i;
457 
458     pp = xcalloc(1, sizeof(*pp));
459     pp->p_pid = pid;
460     pp->p_flags = t->t_dflg & F_AMPERSAND ? PRUNNING : PRUNNING | PFOREGND;
461     if (t->t_dflg & F_TIME)
462 	pp->p_flags |= PPTIME;
463     cmdp = command;
464     cmdlen = 0;
465     padd(t);
466     *cmdp++ = 0;
467     if (t->t_dflg & F_PIPEOUT) {
468 	pp->p_flags |= PPOU;
469 	if (t->t_dflg & F_STDERR)
470 	    pp->p_flags |= PERR;
471     }
472     pp->p_command = Strsave(command);
473     if (pcurrjob) {
474 	struct process *fp;
475 
476 	/* careful here with interrupt level */
477 	pp->p_cwd = 0;
478 	pp->p_index = pcurrjob->p_index;
479 	pp->p_friends = pcurrjob;
480 	pp->p_jobid = pcurrjob->p_pid;
481 	for (fp = pcurrjob; fp->p_friends != pcurrjob; fp = fp->p_friends)
482 	    continue;
483 	fp->p_friends = pp;
484     }
485     else {
486 	pcurrjob = pp;
487 	pp->p_jobid = pid;
488 	pp->p_friends = pp;
489 	pp->p_cwd = dcwd;
490 	dcwd->di_count++;
491 	if (pmaxindex < BIGINDEX)
492 	    pp->p_index = ++pmaxindex;
493 	else {
494 	    struct process *np;
495 
496 	    for (i = 1;; i++) {
497 		for (np = proclist.p_next; np; np = np->p_next)
498 		    if (np->p_index == i)
499 			goto tryagain;
500 		pp->p_index = i;
501 		if (i > pmaxindex)
502 		    pmaxindex = i;
503 		break;
504 	tryagain:;
505 	    }
506 	}
507 	if (pcurrent == NULL)
508 	    pcurrent = pp;
509 	else if (pprevious == NULL)
510 	    pprevious = pp;
511     }
512     pp->p_next = proclist.p_next;
513     proclist.p_next = pp;
514     (void)clock_gettime(CLOCK_MONOTONIC, &pp->p_btime);
515 }
516 
517 static void
518 padd(struct command *t)
519 {
520     Char **argp;
521 
522     if (t == 0)
523 	return;
524     switch (t->t_dtyp) {
525     case NODE_PAREN:
526 	pads(STRLparensp);
527 	padd(t->t_dspr);
528 	pads(STRspRparen);
529 	break;
530     case NODE_COMMAND:
531 	for (argp = t->t_dcom; *argp; argp++) {
532 	    pads(*argp);
533 	    if (argp[1])
534 		pads(STRspace);
535 	}
536 	break;
537     case NODE_OR:
538     case NODE_AND:
539     case NODE_PIPE:
540     case NODE_LIST:
541 	padd(t->t_dcar);
542 	switch (t->t_dtyp) {
543 	case NODE_OR:
544 	    pads(STRspor2sp);
545 	    break;
546 	case NODE_AND:
547 	    pads(STRspand2sp);
548 	    break;
549 	case NODE_PIPE:
550 	    pads(STRsporsp);
551 	    break;
552 	case NODE_LIST:
553 	    pads(STRsemisp);
554 	    break;
555 	}
556 	padd(t->t_dcdr);
557 	return;
558     }
559     if ((t->t_dflg & F_PIPEIN) == 0 && t->t_dlef) {
560 	pads((t->t_dflg & F_READ) ? STRspLarrow2sp : STRspLarrowsp);
561 	pads(t->t_dlef);
562     }
563     if ((t->t_dflg & F_PIPEOUT) == 0 && t->t_drit) {
564 	pads((t->t_dflg & F_APPEND) ? STRspRarrow2 : STRspRarrow);
565 	if (t->t_dflg & F_STDERR)
566 	    pads(STRand);
567 	pads(STRspace);
568 	pads(t->t_drit);
569     }
570 }
571 
572 static void
573 pads(Char *cp)
574 {
575     size_t i;
576 
577     /*
578      * Avoid the Quoted Space alias hack! Reported by:
579      * sam@john-bigboote.ICS.UCI.EDU (Sam Horrocks)
580      */
581     if (cp[0] == STRQNULL[0])
582 	cp++;
583 
584     i = Strlen(cp);
585 
586     if (cmdlen >= PMAXLEN)
587 	return;
588     if (cmdlen + i >= PMAXLEN) {
589 	(void)Strcpy(cmdp, STRsp3dots);
590 	cmdlen = PMAXLEN;
591 	cmdp += 4;
592 	return;
593     }
594     (void)Strcpy(cmdp, cp);
595     cmdp += i;
596     cmdlen += i;
597 }
598 
599 /*
600  * psavejob - temporarily save the current job on a one level stack
601  *	so another job can be created.  Used for { } in exp6
602  *	and `` in globbing.
603  */
604 void
605 psavejob(void)
606 {
607     pholdjob = pcurrjob;
608     pcurrjob = NULL;
609 }
610 
611 /*
612  * prestjob - opposite of psavejob.  This may be missed if we are interrupted
613  *	somewhere, but pendjob cleans up anyway.
614  */
615 void
616 prestjob(void)
617 {
618     pcurrjob = pholdjob;
619     pholdjob = NULL;
620 }
621 
622 /*
623  * pendjob - indicate that a job (set of commands) has been completed
624  *	or is about to begin.
625  */
626 void
627 pendjob(void)
628 {
629     struct process *pp, *tp;
630 
631     if (pcurrjob && (pcurrjob->p_flags & (PFOREGND | PSTOPPED)) == 0) {
632 	pp = pcurrjob;
633 	while (pp->p_pid != pp->p_jobid)
634 	    pp = pp->p_friends;
635 	(void)fprintf(cshout, "[%d]", pp->p_index);
636 	tp = pp;
637 	do {
638 	    (void)fprintf(cshout, " %ld", (long)pp->p_pid);
639 	    pp = pp->p_friends;
640 	} while (pp != tp);
641 	(void)fputc('\n', cshout);
642     }
643     pholdjob = pcurrjob = 0;
644 }
645 
646 /*
647  * pprint - print a job
648  */
649 static int
650 pprint(struct process *pp, int flag)
651 {
652     static struct rusage zru;
653     struct process *tp;
654     const char *format;
655     int jobflags, pstatus, reason, status;
656     int hadnl;
657 
658     hadnl = 1; /* did we just have a newline */
659     (void)fpurge(cshout);
660 
661     while (pp->p_pid != pp->p_jobid)
662 	pp = pp->p_friends;
663     if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
664 	pp->p_flags &= ~PPTIME;
665 	pp->p_flags |= PTIME;
666     }
667     tp = pp;
668     status = reason = -1;
669     jobflags = 0;
670     do {
671 	jobflags |= pp->p_flags;
672 	pstatus = pp->p_flags & PALLSTATES;
673 	if (tp != pp && !hadnl && !(flag & FANCY) &&
674 	    ((pstatus == status && pp->p_reason == reason) ||
675 	     !(flag & REASON))) {
676 	    (void)fputc(' ', cshout);
677 	    hadnl = 0;
678 	}
679 	else {
680 	    if (tp != pp && !hadnl) {
681 		(void)fputc('\n', cshout);
682 		hadnl = 1;
683 	    }
684 	    if (flag & NUMBER) {
685 		if (pp == tp)
686 		    (void)fprintf(cshout, "[%d]%s %c ", pp->p_index,
687 			    pp->p_index < 10 ? " " : "",
688 			    pp == pcurrent ? '+' :
689 			    (pp == pprevious ? '-' : ' '));
690 		else
691 		    (void)fprintf(cshout, "       ");
692 		hadnl = 0;
693 	    }
694 	    if (flag & FANCY) {
695 		(void)fprintf(cshout, "%5ld ", (long)pp->p_pid);
696 		hadnl = 0;
697 	    }
698 	    if (flag & (REASON | AREASON)) {
699 		if (flag & NAME)
700 		    format = "%-23s";
701 		else
702 		    format = "%s";
703 		if (pstatus == status) {
704 		    if (pp->p_reason == reason) {
705 			(void)fprintf(cshout, format, "");
706 			hadnl = 0;
707 			goto prcomd;
708 		    }
709 		    else
710 			reason = pp->p_reason;
711 		} else {
712 		    status = pstatus;
713 		    reason = pp->p_reason;
714 		}
715 		switch (status) {
716 		case PRUNNING:
717 		    (void)fprintf(cshout, format, "Running ");
718 		    hadnl = 0;
719 		    break;
720 		case PINTERRUPTED:
721 		case PSTOPPED:
722 		case PSIGNALED:
723                     /*
724                      * tell what happened to the background job
725                      * From: Michael Schroeder
726                      * <mlschroe@immd4.informatik.uni-erlangen.de>
727                      */
728                     if ((flag & REASON)
729                         || ((flag & AREASON)
730                             && reason != SIGINT
731                             && (reason != SIGPIPE
732                                 || (pp->p_flags & PPOU) == 0))) {
733 			(void)fprintf(cshout, format,
734 				       sys_siglist[(unsigned char)
735 						   pp->p_reason]);
736 			hadnl = 0;
737 		    }
738 		    break;
739 		case PNEXITED:
740 		case PAEXITED:
741 		    if (flag & REASON) {
742 			if (pp->p_reason)
743 			    (void)fprintf(cshout, "Exit %-18d", pp->p_reason);
744 			else
745 			    (void)fprintf(cshout, format, "Done");
746 			hadnl = 0;
747 		    }
748 		    break;
749 		default:
750 		    (void)fprintf(csherr, "BUG: status=%-9o", status);
751 		}
752 	    }
753 	}
754 prcomd:
755 	if (flag & NAME) {
756 	    (void)fprintf(cshout, "%s", vis_str(pp->p_command));
757 	    if (pp->p_flags & PPOU)
758 		(void)fprintf(cshout, " |");
759 	    if (pp->p_flags & PERR)
760 		(void)fputc('&', cshout);
761 	    hadnl = 0;
762 	}
763 	if (flag & (REASON | AREASON) && pp->p_flags & PDUMPED) {
764 	    (void)fprintf(cshout, " (core dumped)");
765 	    hadnl = 0;
766 	}
767 	if (tp == pp->p_friends) {
768 	    if (flag & AMPERSAND) {
769 		(void)fprintf(cshout, " &");
770 		hadnl = 0;
771 	    }
772 	    if (flag & JOBDIR &&
773 		!eq(tp->p_cwd->di_name, dcwd->di_name)) {
774 		(void)fprintf(cshout, " (wd: ");
775 		dtildepr(value(STRhome), tp->p_cwd->di_name);
776 		(void)fputc(')', cshout);
777 		hadnl = 0;
778 	    }
779 	}
780 	if (pp->p_flags & PPTIME && !(status & (PSTOPPED | PRUNNING))) {
781 	    if (!hadnl)
782 		(void)fprintf(cshout, "\n\t");
783 	    prusage(cshout, &zru, &pp->p_rusage, &pp->p_etime,
784 		    &pp->p_btime);
785 	    hadnl = 1;
786 	}
787 	if (tp == pp->p_friends) {
788 	    if (!hadnl) {
789 		(void)fputc('\n', cshout);
790 		hadnl = 1;
791 	    }
792 	    if (flag & SHELLDIR && !eq(tp->p_cwd->di_name, dcwd->di_name)) {
793 		(void)fprintf(cshout, "(wd now: ");
794 		dtildepr(value(STRhome), dcwd->di_name);
795 		(void)fprintf(cshout, ")\n");
796 		hadnl = 1;
797 	    }
798 	}
799     } while ((pp = pp->p_friends) != tp);
800     if (jobflags & PTIME && (jobflags & (PSTOPPED | PRUNNING)) == 0) {
801 	if (jobflags & NUMBER)
802 	    (void)fprintf(cshout, "       ");
803 	ptprint(tp);
804 	hadnl = 1;
805     }
806     (void)fflush(cshout);
807     return (jobflags);
808 }
809 
810 static void
811 ptprint(struct process *tp)
812 {
813     static struct rusage zru;
814     static struct timespec ztime;
815     struct rusage ru;
816     struct timespec tetime, diff;
817     struct process *pp;
818 
819     pp = tp;
820     ru = zru;
821     tetime = ztime;
822     do {
823 	ruadd(&ru, &pp->p_rusage);
824 	timespecsub(&pp->p_etime, &pp->p_btime, &diff);
825 	if (timespeccmp(&diff, &tetime, >))
826 	    tetime = diff;
827     } while ((pp = pp->p_friends) != tp);
828     prusage(cshout, &zru, &ru, &tetime, &ztime);
829 }
830 
831 /*
832  * dojobs - print all jobs
833  */
834 void
835 /*ARGSUSED*/
836 dojobs(Char **v, struct command *t)
837 {
838     struct process *pp;
839     int flag, i;
840 
841     flag = NUMBER | NAME | REASON;
842     if (chkstop)
843 	chkstop = 2;
844     if (*++v) {
845 	if (v[1] || !eq(*v, STRml))
846 	    stderror(ERR_JOBS);
847 	flag |= FANCY | JOBDIR;
848     }
849     for (i = 1; i <= pmaxindex; i++)
850 	for (pp = proclist.p_next; pp; pp = pp->p_next)
851 	    if (pp->p_index == i && pp->p_pid == pp->p_jobid) {
852 		pp->p_flags &= ~PNEEDNOTE;
853 		if (!(pprint(pp, flag) & (PRUNNING | PSTOPPED)))
854 		    pflush(pp);
855 		break;
856 	    }
857 }
858 
859 /*
860  * dofg - builtin - put the job into the foreground
861  */
862 void
863 /*ARGSUSED*/
864 dofg(Char **v, struct command *t)
865 {
866     struct process *pp;
867 
868     okpcntl();
869     ++v;
870     do {
871 	pp = pfind(*v);
872 	pstart(pp, 1);
873 	pjwait(pp);
874     } while (*v && *++v);
875 }
876 
877 /*
878  * %... - builtin - put the job into the foreground
879  */
880 void
881 /*ARGSUSED*/
882 dofg1(Char **v, struct command *t)
883 {
884     struct process *pp;
885 
886     okpcntl();
887     pp = pfind(v[0]);
888     pstart(pp, 1);
889     pjwait(pp);
890 }
891 
892 /*
893  * dobg - builtin - put the job into the background
894  */
895 void
896 /*ARGSUSED*/
897 dobg(Char **v, struct command *t)
898 {
899     struct process *pp;
900 
901     okpcntl();
902     ++v;
903     do {
904 	pp = pfind(*v);
905 	pstart(pp, 0);
906     } while (*v && *++v);
907 }
908 
909 /*
910  * %... & - builtin - put the job into the background
911  */
912 void
913 /*ARGSUSED*/
914 dobg1(Char **v, struct command *t)
915 {
916     struct process *pp;
917 
918     pp = pfind(v[0]);
919     pstart(pp, 0);
920 }
921 
922 /*
923  * dostop - builtin - stop the job
924  */
925 void
926 /*ARGSUSED*/
927 dostop(Char **v, struct command *t)
928 {
929     pkill(++v, SIGSTOP);
930 }
931 
932 /*
933  * dokill - builtin - superset of kill (1)
934  */
935 void
936 /*ARGSUSED*/
937 dokill(Char **v, struct command *t)
938 {
939     Char *signame;
940     char *name;
941     long signum;
942     char *ep;
943 
944     signum = SIGTERM;
945     v++;
946     if (v[0] && v[0][0] == '-') {
947 	if (v[0][1] == 'l') {
948 	    if (v[1]) {
949 		if (!Isdigit(v[1][0]))
950 		    stderror(ERR_NAME | ERR_BADSIG);
951 
952 		signum = strtol(short2str(v[1]), &ep, 10);
953 		if (signum < 0 || signum >= NSIG)
954 		    stderror(ERR_NAME | ERR_BADSIG);
955 		else if (signum == 0)
956 		    (void)fputc('0', cshout); /* 0's symbolic name is '0' */
957 		else
958 		    (void)fprintf(cshout, "%s ", sys_signame[signum]);
959 	    } else {
960 		for (signum = 1; signum < NSIG; signum++) {
961 		    (void)fprintf(cshout, "%s ", sys_signame[signum]);
962 		    if (signum == NSIG / 2)
963 			(void)fputc('\n', cshout);
964 	    	}
965 	    }
966 	    (void)fputc('\n', cshout);
967 	    return;
968 	}
969 	if (Isdigit(v[0][1])) {
970 	    signum = strtol(short2str(v[0] + 1), &ep, 10);
971 	    if (signum < 0 || signum >= NSIG || *ep)
972 		stderror(ERR_NAME | ERR_BADSIG);
973 	}
974 	else {
975 	    if (v[0][1] == 's' && v[0][2] == '\0')
976 		signame = *(++v);
977 	    else
978 		signame = &v[0][1];
979 
980 	    if (signame == NULL || v[1] == NULL)
981 		stderror(ERR_NAME | ERR_TOOFEW);
982 
983 	    name = short2str(signame);
984 	    for (signum = 1; signum < NSIG; signum++)
985 		if (!strcasecmp(sys_signame[signum], name) ||
986 		    (!strncasecmp("SIG", name, 3) &&	/* skip "SIG" prefix */
987 		     !strcasecmp(sys_signame[signum], name + 3)))
988 		    break;
989 
990 	    if (signum == NSIG) {
991 		if (signame[0] == '0')
992 		    signum = 0;
993 		else {
994 		    setname(vis_str(signame));
995 		    stderror(ERR_NAME | ERR_UNKSIG);
996 		}
997 	    }
998 	}
999 	v++;
1000     }
1001     pkill(v, (int)signum);
1002 }
1003 
1004 static void
1005 pkill(Char **v, int signum)
1006 {
1007     struct process *pp, *np;
1008     Char *cp;
1009     sigset_t nsigset;
1010     int err1, jobflags, pid;
1011     char *ep;
1012 
1013     jobflags = 0;
1014     err1 = 0;
1015     sigemptyset(&nsigset);
1016     (void)sigaddset(&nsigset, SIGCHLD);
1017     if (setintr)
1018 	(void)sigaddset(&nsigset, SIGINT);
1019     (void)sigprocmask(SIG_BLOCK, &nsigset, NULL);
1020     gflag = 0, tglob(v);
1021     if (gflag) {
1022 	v = globall(v);
1023 	if (v == 0)
1024 	    stderror(ERR_NAME | ERR_NOMATCH);
1025     }
1026     else {
1027 	v = gargv = saveblk(v);
1028 	trim(v);
1029     }
1030 
1031     while (v && (cp = *v)) {
1032 	if (*cp == '%') {
1033 	    np = pp = pfind(cp);
1034 	    do
1035 		jobflags |= np->p_flags;
1036 	    while ((np = np->p_friends) != pp);
1037 	    switch (signum) {
1038 	    case SIGSTOP:
1039 	    case SIGTSTP:
1040 	    case SIGTTIN:
1041 	    case SIGTTOU:
1042 		if ((jobflags & PRUNNING) == 0) {
1043 		    (void)fprintf(csherr, "%s: Already suspended\n",
1044 				   vis_str(cp));
1045 		    err1++;
1046 		    goto cont;
1047 		}
1048 		break;
1049 		/*
1050 		 * suspend a process, kill -CONT %, then type jobs; the shell
1051 		 * says it is suspended, but it is running; thanks jaap..
1052 		 */
1053 	    case SIGCONT:
1054 		pstart(pp, 0);
1055 		goto cont;
1056 	    }
1057 	    if (kill(-pp->p_jobid, signum) < 0) {
1058 		(void)fprintf(csherr, "%s: %s\n", vis_str(cp),
1059 			       strerror(errno));
1060 		err1++;
1061 	    }
1062 	    if (signum == SIGTERM || signum == SIGHUP)
1063 		(void)kill(-pp->p_jobid, SIGCONT);
1064 	}
1065 	else if (!(Isdigit(*cp) || *cp == '-'))
1066 	    stderror(ERR_NAME | ERR_JOBARGS);
1067 	else {
1068 	    pid = (pid_t)strtoul(short2str(cp), &ep, 0);
1069 	    if (*ep) {
1070 		(void)fprintf(csherr, "%s: Badly formed number\n",
1071 		    short2str(cp));
1072 		err1++;
1073 		goto cont;
1074 	    } else if (kill(pid, signum) < 0) {
1075 		(void)fprintf(csherr, "%d: %s\n", pid, strerror(errno));
1076 		err1++;
1077 		goto cont;
1078 	    }
1079 	    if (signum == SIGTERM || signum == SIGHUP)
1080 		(void)kill((pid_t) pid, SIGCONT);
1081 	}
1082 cont:
1083 	v++;
1084     }
1085     if (gargv)
1086 	blkfree(gargv), gargv = 0;
1087     (void)sigprocmask(SIG_UNBLOCK, &nsigset, NULL);
1088     if (err1)
1089 	stderror(ERR_SILENT);
1090 }
1091 
1092 /*
1093  * pstart - start the job in foreground/background
1094  */
1095 void
1096 pstart(struct process *pp, int foregnd)
1097 {
1098     struct process *np;
1099     sigset_t osigset, nsigset;
1100     long jobflags;
1101 
1102     jobflags = 0;
1103     sigemptyset(&nsigset);
1104     (void)sigaddset(&nsigset, SIGCHLD);
1105     (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
1106     np = pp;
1107     do {
1108 	jobflags |= np->p_flags;
1109 	if (np->p_flags & (PRUNNING | PSTOPPED)) {
1110 	    np->p_flags |= PRUNNING;
1111 	    np->p_flags &= ~PSTOPPED;
1112 	    if (foregnd)
1113 		np->p_flags |= PFOREGND;
1114 	    else
1115 		np->p_flags &= ~PFOREGND;
1116 	}
1117     } while ((np = np->p_friends) != pp);
1118     if (!foregnd)
1119 	pclrcurr(pp);
1120     (void)pprint(pp, foregnd ? NAME | JOBDIR : NUMBER | NAME | AMPERSAND);
1121     if (foregnd)
1122 	(void)tcsetpgrp(FSHTTY, pp->p_jobid);
1123     if (jobflags & PSTOPPED)
1124 	(void)kill(-pp->p_jobid, SIGCONT);
1125     (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
1126 }
1127 
1128 void
1129 panystop(int neednl)
1130 {
1131     struct process *pp;
1132 
1133     chkstop = 2;
1134     for (pp = proclist.p_next; pp; pp = pp->p_next)
1135 	if (pp->p_flags & PSTOPPED)
1136 	    stderror(ERR_STOPPED, neednl ? "\n" : "");
1137 }
1138 
1139 struct process *
1140 pfind(Char *cp)
1141 {
1142     struct process *pp, *np;
1143 
1144     if (cp == 0 || cp[1] == 0 || eq(cp, STRcent2) || eq(cp, STRcentplus)) {
1145 	if (pcurrent == NULL)
1146 	    stderror(ERR_NAME | ERR_JOBCUR);
1147 	return (pcurrent);
1148     }
1149     if (eq(cp, STRcentminus) || eq(cp, STRcenthash)) {
1150 	if (pprevious == NULL)
1151 	    stderror(ERR_NAME | ERR_JOBPREV);
1152 	return (pprevious);
1153     }
1154     if (Isdigit(cp[1])) {
1155 	int     idx = atoi(short2str(cp + 1));
1156 
1157 	for (pp = proclist.p_next; pp; pp = pp->p_next)
1158 	    if (pp->p_index == idx && pp->p_pid == pp->p_jobid)
1159 		return (pp);
1160 	stderror(ERR_NAME | ERR_NOSUCHJOB);
1161     }
1162     np = NULL;
1163     for (pp = proclist.p_next; pp; pp = pp->p_next)
1164 	if (pp->p_pid == pp->p_jobid) {
1165 	    if (cp[1] == '?') {
1166 		Char *dp;
1167 
1168 		for (dp = pp->p_command; *dp; dp++) {
1169 		    if (*dp != cp[2])
1170 			continue;
1171 		    if (prefix(cp + 2, dp))
1172 			goto match;
1173 		}
1174 	    }
1175 	    else if (prefix(cp + 1, pp->p_command)) {
1176 	match:
1177 		if (np)
1178 		    stderror(ERR_NAME | ERR_AMBIG);
1179 		np = pp;
1180 	    }
1181 	}
1182     if (np)
1183 	return (np);
1184     stderror(ERR_NAME | (cp[1] == '?' ? ERR_JOBPAT : ERR_NOSUCHJOB));
1185     /* NOTREACHED */
1186 }
1187 
1188 /*
1189  * pgetcurr - find most recent job that is not pp, preferably stopped
1190  */
1191 static struct process *
1192 pgetcurr(struct process *pp)
1193 {
1194     struct process *np, *xp;
1195 
1196     xp = NULL;
1197     for (np = proclist.p_next; np; np = np->p_next)
1198 	if (np != pcurrent && np != pp && np->p_pid &&
1199 	    np->p_pid == np->p_jobid) {
1200 	    if (np->p_flags & PSTOPPED)
1201 		return (np);
1202 	    if (xp == NULL)
1203 		xp = np;
1204 	}
1205     return (xp);
1206 }
1207 
1208 /*
1209  * donotify - flag the job so as to report termination asynchronously
1210  */
1211 void
1212 /*ARGSUSED*/
1213 donotify(Char **v, struct command *t)
1214 {
1215     struct process *pp;
1216 
1217     pp = pfind(*++v);
1218     pp->p_flags |= PNOTIFY;
1219 }
1220 
1221 /*
1222  * Do the fork and whatever should be done in the child side that
1223  * should not be done if we are not forking at all (like for simple builtin's)
1224  * Also do everything that needs any signals fiddled with in the parent side
1225  *
1226  * Wanttty tells whether process and/or tty pgrps are to be manipulated:
1227  *	-1:	leave tty alone; inherit pgrp from parent
1228  *	 0:	already have tty; manipulate process pgrps only
1229  *	 1:	want to claim tty; manipulate process and tty pgrps
1230  * It is usually just the value of tpgrp.
1231  */
1232 
1233 int
1234 pfork(struct command *t /* command we are forking for */, int wanttty)
1235 {
1236     int pgrp, pid;
1237     sigset_t osigset, nsigset;
1238     int ignint;
1239 
1240     ignint = 0;
1241     /*
1242      * A child will be uninterruptible only under very special conditions.
1243      * Remember that the semantics of '&' is implemented by disconnecting the
1244      * process from the tty so signals do not need to ignored just for '&'.
1245      * Thus signals are set to default action for children unless: we have had
1246      * an "onintr -" (then specifically ignored) we are not playing with
1247      * signals (inherit action)
1248      */
1249     if (setintr)
1250 	ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT))
1251 	    || (gointr && eq(gointr, STRminus));
1252     /*
1253      * Check for maximum nesting of 16 processes to avoid Forking loops
1254      */
1255     if (child == 16)
1256 	stderror(ERR_NESTING, 16);
1257     /*
1258      * Hold SIGCHLD until we have the process installed in our table.
1259      */
1260     sigemptyset(&nsigset);
1261     (void)sigaddset(&nsigset, SIGCHLD);
1262     (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
1263     while ((pid = fork()) < 0)
1264 	if (setintr == 0)
1265 	    (void)sleep(FORKSLEEP);
1266 	else {
1267 	    (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
1268 	    stderror(ERR_NOPROC);
1269 	}
1270     if (pid == 0) {
1271 	settimes();
1272 	pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
1273 	pflushall();
1274 	pcurrjob = NULL;
1275 	child++;
1276 	if (setintr) {
1277 	    setintr = 0;	/* until I think otherwise */
1278 	    /*
1279 	     * Children just get blown away on SIGINT, SIGQUIT unless "onintr
1280 	     * -" seen.
1281 	     */
1282 	    (void)signal(SIGINT, ignint ? SIG_IGN : SIG_DFL);
1283 	    (void)signal(SIGQUIT, ignint ? SIG_IGN : SIG_DFL);
1284 	    if (wanttty >= 0) {
1285 		/* make stoppable */
1286 		(void)signal(SIGTSTP, SIG_DFL);
1287 		(void)signal(SIGTTIN, SIG_DFL);
1288 		(void)signal(SIGTTOU, SIG_DFL);
1289 	    }
1290 	    (void)signal(SIGTERM, parterm);
1291 	}
1292 	else if (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) {
1293 	    (void)signal(SIGINT, SIG_IGN);
1294 	    (void)signal(SIGQUIT, SIG_IGN);
1295 	}
1296 	pgetty(wanttty, pgrp);
1297 	/*
1298 	 * Nohup and nice apply only to NODE_COMMAND's but it would be nice
1299 	 * (?!?) if you could say "nohup (foo;bar)" Then the parser would have
1300 	 * to know about nice/nohup/time
1301 	 */
1302 	if (t->t_dflg & F_NOHUP)
1303 	    (void)signal(SIGHUP, SIG_IGN);
1304 	if (t->t_dflg & F_NICE)
1305 	    (void)setpriority(PRIO_PROCESS, 0, t->t_nice);
1306     }
1307     else {
1308 	if (wanttty >= 0)
1309 	    (void)setpgid(pid, pcurrjob ? pcurrjob->p_jobid : pid);
1310 	palloc(pid, t);
1311 	(void)sigprocmask(SIG_SETMASK, &osigset, NULL);
1312     }
1313 
1314     return (pid);
1315 }
1316 
1317 static void
1318 okpcntl(void)
1319 {
1320     if (tpgrp == -1)
1321 	stderror(ERR_JOBCONTROL);
1322     if (tpgrp == 0)
1323 	stderror(ERR_JOBCTRLSUB);
1324     /* NOTREACHED */
1325 }
1326 
1327 /*
1328  * if we don't have vfork(), things can still go in the wrong order
1329  * resulting in the famous 'Stopped (tty output)'. But some systems
1330  * don't permit the setpgid() call, (these are more recent secure
1331  * systems such as ibm's aix). Then we'd rather print an error message
1332  * than hang the shell!
1333  * I am open to suggestions how to fix that.
1334  */
1335 void
1336 pgetty(int wanttty, int pgrp)
1337 {
1338     sigset_t osigset, nsigset;
1339 
1340     /*
1341      * christos: I am blocking the tty signals till I've set things
1342      * correctly....
1343      */
1344     if (wanttty > 0) {
1345 	sigemptyset(&nsigset);
1346 	(void)sigaddset(&nsigset, SIGTSTP);
1347 	(void)sigaddset(&nsigset, SIGTTIN);
1348 	(void)sigaddset(&nsigset, SIGTTOU);
1349 	(void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
1350     }
1351     /*
1352      * From: Michael Schroeder <mlschroe@immd4.informatik.uni-erlangen.de>
1353      * Don't check for tpgrp >= 0 so even non-interactive shells give
1354      * background jobs process groups Same for the comparison in the other part
1355      * of the #ifdef
1356      */
1357     if (wanttty >= 0)
1358 	if (setpgid(0, pgrp) == -1) {
1359 	    (void)fprintf(csherr, "csh: setpgid error.\n");
1360 	    xexit(0);
1361 	}
1362 
1363     if (wanttty > 0) {
1364 	(void)tcsetpgrp(FSHTTY, pgrp);
1365 	(void)sigprocmask(SIG_SETMASK, &osigset, NULL);
1366     }
1367 
1368     if (tpgrp > 0)
1369 	tpgrp = 0;		/* gave tty away */
1370 }
1371