xref: /openbsd/bin/csh/proc.c (revision 097a140d)
1 /*	$OpenBSD: proc.c,v 1.34 2020/08/30 22:23:47 mortimer Exp $	*/
2 /*	$NetBSD: proc.c,v 1.9 1995/04/29 23:21:33 mycroft Exp $	*/
3 
4 /*-
5  * Copyright (c) 1980, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
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/types.h>
34 #include <sys/wait.h>
35 #include <errno.h>
36 #include <unistd.h>
37 #include <limits.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <stdarg.h>
41 
42 #include "csh.h"
43 #include "dir.h"
44 #include "proc.h"
45 #include "extern.h"
46 
47 #define BIGINDEX	9	/* largest desirable job index */
48 
49 struct process proclist;        /* list head of all processes */
50 bool    pnoprocesses;           /* pchild found nothing to wait for */
51 
52 struct process *pholdjob;       /* one level stack of current jobs */
53 
54 struct process *pcurrjob;       /* current job */
55 struct process *pcurrent;       /* current job in table */
56 struct process *pprevious;      /* previous job in table */
57 
58 int    pmaxindex;               /* current maximum job index */
59 
60 static struct rusage zru;
61 
62 static void	 pflushall(void);
63 static void	 pflush(struct process *);
64 static void	 pclrcurr(struct process *);
65 static void	 padd(struct command *);
66 static int	 pprint(struct process *, int);
67 static void	 ptprint(struct process *);
68 static void	 pads(Char *);
69 static void	 pkill(Char **v, int);
70 static struct	process
71 		*pgetcurr(struct process *);
72 static void	 okpcntl(void);
73 
74 /*
75  * pchild - called at interrupt level by the SIGCHLD signal
76  *	indicating that at least one child has terminated or stopped
77  *	thus at least one wait system call will definitely return a
78  *	childs status.  Top level routines (like pwait) must be sure
79  *	to mask interrupts when playing with the proclist data structures!
80  */
81 /* ARGUSED */
82 void
83 pchild(int notused)
84 {
85     struct process *pp;
86     struct process *fp;
87     int pid;
88     extern int insource;
89     int save_errno = errno;
90     int w;
91     int     jobflags;
92     struct rusage ru;
93 
94 loop:
95     errno = 0;			/* reset, just in case */
96     pid = wait3(&w,
97        (setintr && (intty || insource) ? WNOHANG | WUNTRACED : WNOHANG), &ru);
98 
99     if (pid <= 0) {
100 	if (errno == EINTR) {
101 	    errno = 0;
102 	    goto loop;
103 	}
104 	pnoprocesses = pid == -1;
105 	errno = save_errno;
106 	return;
107     }
108     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
109 	if (pid == pp->p_pid)
110 	    goto found;
111     goto loop;
112 found:
113     if (pid == atoi(short2str(value(STRchild))))
114 	unsetv(STRchild);
115     pp->p_flags &= ~(PRUNNING | PSTOPPED | PREPORTED);
116     if (WIFSTOPPED(w)) {
117 	pp->p_flags |= PSTOPPED;
118 	pp->p_reason = WSTOPSIG(w);
119     }
120     else {
121 	if (pp->p_flags & (PTIME | PPTIME) || adrof(STRtime))
122 	    (void) clock_gettime(CLOCK_MONOTONIC, &pp->p_etime);
123 
124 	pp->p_rusage = ru;
125 	if (WIFSIGNALED(w)) {
126 	    if (WTERMSIG(w) == SIGINT)
127 		pp->p_flags |= PINTERRUPTED;
128 	    else
129 		pp->p_flags |= PSIGNALED;
130 	    if (WCOREDUMP(w))
131 		pp->p_flags |= PDUMPED;
132 	    pp->p_reason = WTERMSIG(w);
133 	}
134 	else {
135 	    pp->p_reason = WEXITSTATUS(w);
136 	    if (pp->p_reason != 0)
137 		pp->p_flags |= PAEXITED;
138 	    else
139 		pp->p_flags |= PNEXITED;
140 	}
141     }
142     jobflags = 0;
143     fp = pp;
144     do {
145 	if ((fp->p_flags & (PPTIME | PRUNNING | PSTOPPED)) == 0 &&
146 	    !child && adrof(STRtime) &&
147 	    fp->p_rusage.ru_utime.tv_sec + fp->p_rusage.ru_stime.tv_sec
148 	    >= atoi(short2str(value(STRtime))))
149 	    fp->p_flags |= PTIME;
150 	jobflags |= fp->p_flags;
151     } while ((fp = fp->p_friends) != pp);
152     pp->p_flags &= ~PFOREGND;
153     if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
154 	pp->p_flags &= ~PPTIME;
155 	pp->p_flags |= PTIME;
156     }
157     if ((jobflags & (PRUNNING | PREPORTED)) == 0) {
158 	fp = pp;
159 	do {
160 	    if (fp->p_flags & PSTOPPED)
161 		fp->p_flags |= PREPORTED;
162 	} while ((fp = fp->p_friends) != pp);
163 	while (fp->p_pid != fp->p_jobid)
164 	    fp = fp->p_friends;
165 	if (jobflags & PSTOPPED) {
166 	    if (pcurrent && pcurrent != fp)
167 		pprevious = pcurrent;
168 	    pcurrent = fp;
169 	}
170 	else
171 	    pclrcurr(fp);
172 	if (jobflags & PFOREGND) {
173 	    if (jobflags & (PSIGNALED | PSTOPPED | PPTIME) ||
174 		!eq(dcwd->di_name, fp->p_cwd->di_name)) {
175 		;		/* print in pjwait */
176 	    }
177 	    /* PWP: print a newline after ^C */
178 	    else if (jobflags & PINTERRUPTED) {
179 		(void) vis_fputc('\r' | QUOTE, cshout);
180 		(void) fputc('\n', cshout);
181 	    }
182 	}
183 	else {
184 	    if (jobflags & PNOTIFY || adrof(STRnotify)) {
185 		(void) vis_fputc('\r' | QUOTE, cshout);
186 		(void) fputc('\n', cshout);
187 		(void) pprint(pp, NUMBER | NAME | REASON);
188 		if ((jobflags & PSTOPPED) == 0)
189 		    pflush(pp);
190 	    }
191 	    else {
192 		fp->p_flags |= PNEEDNOTE;
193 		neednote++;
194 	    }
195 	}
196     }
197     goto loop;
198 }
199 
200 void
201 pnote(void)
202 {
203     struct process *pp;
204     int     flags;
205     sigset_t sigset, osigset;
206 
207     neednote = 0;
208     sigemptyset(&sigset);
209     sigaddset(&sigset, SIGCHLD);
210     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next) {
211 	if (pp->p_flags & PNEEDNOTE) {
212 	    sigprocmask(SIG_BLOCK, &sigset, &osigset);
213 	    pp->p_flags &= ~PNEEDNOTE;
214 	    flags = pprint(pp, NUMBER | NAME | REASON);
215 	    if ((flags & (PRUNNING | PSTOPPED)) == 0)
216 		pflush(pp);
217 	    sigprocmask(SIG_SETMASK, &osigset, NULL);
218 	}
219     }
220 }
221 
222 /*
223  * pwait - wait for current job to terminate, maintaining integrity
224  *	of current and previous job indicators.
225  */
226 void
227 pwait(void)
228 {
229     struct process *fp, *pp;
230     sigset_t sigset, osigset;
231 
232     /*
233      * Here's where dead procs get flushed.
234      */
235     sigemptyset(&sigset);
236     sigaddset(&sigset, SIGCHLD);
237     sigprocmask(SIG_BLOCK, &sigset, &osigset);
238     for (pp = (fp = &proclist)->p_next; pp != NULL; pp = (fp = pp)->p_next)
239 	if (pp->p_pid == 0) {
240 	    fp->p_next = pp->p_next;
241 	    free(pp->p_command);
242 	    if (pp->p_cwd && --pp->p_cwd->di_count == 0)
243 		if (pp->p_cwd->di_next == 0)
244 		    dfree(pp->p_cwd);
245 	    free(pp);
246 	    pp = fp;
247 	}
248     sigprocmask(SIG_SETMASK, &osigset, NULL);
249     pjwait(pcurrjob);
250 }
251 
252 
253 /*
254  * pjwait - wait for a job to finish or become stopped
255  *	It is assumed to be in the foreground state (PFOREGND)
256  */
257 void
258 pjwait(struct process *pp)
259 {
260     struct process *fp;
261     int     jobflags, reason;
262     sigset_t sigset, osigset;
263 
264     while (pp->p_pid != pp->p_jobid)
265 	pp = pp->p_friends;
266     fp = pp;
267 
268     do {
269 	if ((fp->p_flags & (PFOREGND | PRUNNING)) == PRUNNING)
270 	    (void) fprintf(csherr, "BUG: waiting for background job!\n");
271     } while ((fp = fp->p_friends) != pp);
272     /*
273      * Now keep pausing as long as we are not interrupted (SIGINT), and the
274      * target process, or any of its friends, are running
275      */
276     fp = pp;
277     sigemptyset(&sigset);
278     sigaddset(&sigset, SIGCHLD);
279     sigprocmask(SIG_BLOCK, &sigset, &osigset);
280     for (;;) {
281 	sigemptyset(&sigset);
282 	sigaddset(&sigset, SIGCHLD);
283 	sigprocmask(SIG_BLOCK, &sigset, NULL);
284 	jobflags = 0;
285 	do
286 	    jobflags |= fp->p_flags;
287 	while ((fp = (fp->p_friends)) != pp);
288 	if ((jobflags & PRUNNING) == 0)
289 	    break;
290 	sigset = osigset;
291 	sigdelset(&sigset, SIGCHLD);
292 	sigsuspend(&sigset);
293     }
294     sigprocmask(SIG_SETMASK, &osigset, NULL);
295     if (tpgrp > 0)		/* get tty back */
296 	(void) tcsetpgrp(FSHTTY, tpgrp);
297     if ((jobflags & (PSIGNALED | PSTOPPED | PTIME)) ||
298 	!eq(dcwd->di_name, fp->p_cwd->di_name)) {
299 	if (jobflags & PSTOPPED) {
300 	    (void) fputc('\n', cshout);
301 	    if (adrof(STRlistjobs)) {
302 		Char   *jobcommand[3];
303 
304 		jobcommand[0] = STRjobs;
305 		if (eq(value(STRlistjobs), STRlong))
306 		    jobcommand[1] = STRml;
307 		else
308 		    jobcommand[1] = NULL;
309 		jobcommand[2] = NULL;
310 
311 		dojobs(jobcommand, NULL);
312 		(void) pprint(pp, SHELLDIR);
313 	    }
314 	    else
315 		(void) pprint(pp, AREASON | SHELLDIR);
316 	}
317 	else
318 	    (void) pprint(pp, AREASON | SHELLDIR);
319     }
320     if ((jobflags & (PINTERRUPTED | PSTOPPED)) && setintr &&
321 	(!gointr || !eq(gointr, STRminus))) {
322 	if ((jobflags & PSTOPPED) == 0)
323 	    pflush(pp);
324 	pintr1(0);
325 	/* NOTREACHED */
326     }
327     reason = 0;
328     fp = pp;
329     do {
330 	if (fp->p_reason)
331 	    reason = fp->p_flags & (PSIGNALED | PINTERRUPTED) ?
332 		fp->p_reason | META : fp->p_reason;
333     } while ((fp = fp->p_friends) != pp);
334     if ((reason != 0) && (adrof(STRprintexitvalue))) {
335 	(void) fprintf(cshout, "Exit %d\n", reason);
336     }
337     set(STRstatus, putn(reason));
338     if (reason && exiterr)
339 	exitstat();
340     pflush(pp);
341 }
342 
343 /*
344  * dowait - wait for all processes to finish
345  */
346 void
347 /*ARGSUSED*/
348 dowait(Char **v, struct command *t)
349 {
350     struct process *pp;
351     sigset_t sigset, osigset;
352 
353     pjobs++;
354     sigemptyset(&sigset);
355     sigaddset(&sigset, SIGCHLD);
356     sigprocmask(SIG_BLOCK, &sigset, &osigset);
357 loop:
358     for (pp = proclist.p_next; pp; pp = pp->p_next)
359 	if (pp->p_pid &&	/* pp->p_pid == pp->p_jobid && */
360 	    pp->p_flags & PRUNNING) {
361 	    sigemptyset(&sigset);
362 	    sigsuspend(&sigset);
363 	    goto loop;
364 	}
365     sigprocmask(SIG_SETMASK, &osigset, NULL);
366     pjobs = 0;
367 }
368 
369 /*
370  * pflushall - flush all jobs from list (e.g. at fork())
371  */
372 static void
373 pflushall(void)
374 {
375     struct process *pp;
376 
377     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
378 	if (pp->p_pid)
379 	    pflush(pp);
380 }
381 
382 /*
383  * pflush - flag all process structures in the same job as the
384  *	the argument process for deletion.  The actual free of the
385  *	space is not done here since pflush is called at interrupt level.
386  */
387 static void
388 pflush(struct process *pp)
389 {
390     struct process *np;
391     int idx;
392 
393     if (pp->p_pid == 0) {
394 	(void) fprintf(csherr, "BUG: process flushed twice");
395 	return;
396     }
397     while (pp->p_pid != pp->p_jobid)
398 	pp = pp->p_friends;
399     pclrcurr(pp);
400     if (pp == pcurrjob)
401 	pcurrjob = 0;
402     idx = pp->p_index;
403     np = pp;
404     do {
405 	np->p_index = np->p_pid = 0;
406 	np->p_flags &= ~PNEEDNOTE;
407     } while ((np = np->p_friends) != pp);
408     if (idx == pmaxindex) {
409 	for (np = proclist.p_next, idx = 0; np; np = np->p_next)
410 	    if (np->p_index > idx)
411 		idx = np->p_index;
412 	pmaxindex = idx;
413     }
414 }
415 
416 /*
417  * pclrcurr - make sure the given job is not the current or previous job;
418  *	pp MUST be the job leader
419  */
420 static void
421 pclrcurr(struct process *pp)
422 {
423 
424     if (pp == pcurrent)
425 	if (pprevious != NULL) {
426 	    pcurrent = pprevious;
427 	    pprevious = pgetcurr(pp);
428 	}
429 	else {
430 	    pcurrent = pgetcurr(pp);
431 	    pprevious = pgetcurr(pp);
432 	}
433     else if (pp == pprevious)
434 	pprevious = pgetcurr(pp);
435 }
436 
437 /* +4 here is 1 for '\0', 1 ea for << >& >> */
438 static Char command[PMAXLEN + 4];
439 static int cmdlen;
440 static Char *cmdp;
441 
442 /*
443  * palloc - allocate a process structure and fill it up.
444  *	an important assumption is made that the process is running.
445  */
446 void
447 palloc(int pid, struct command *t)
448 {
449     struct process *pp;
450     int     i;
451 
452     pp = xcalloc(1, (size_t) sizeof(struct process));
453     pp->p_pid = pid;
454     pp->p_flags = t->t_dflg & F_AMPERSAND ? PRUNNING : PRUNNING | PFOREGND;
455     if (t->t_dflg & F_TIME)
456 	pp->p_flags |= PPTIME;
457     cmdp = command;
458     cmdlen = 0;
459     padd(t);
460     *cmdp++ = 0;
461     if (t->t_dflg & F_PIPEOUT) {
462 	pp->p_flags |= PPOU;
463 	if (t->t_dflg & F_STDERR)
464 	    pp->p_flags |= PERR;
465     }
466     pp->p_command = Strsave(command);
467     if (pcurrjob) {
468 	struct process *fp;
469 
470 	/* careful here with interrupt level */
471 	pp->p_cwd = 0;
472 	pp->p_index = pcurrjob->p_index;
473 	pp->p_friends = pcurrjob;
474 	pp->p_jobid = pcurrjob->p_pid;
475 	for (fp = pcurrjob; fp->p_friends != pcurrjob; fp = fp->p_friends)
476 	    continue;
477 	fp->p_friends = pp;
478     }
479     else {
480 	pcurrjob = pp;
481 	pp->p_jobid = pid;
482 	pp->p_friends = pp;
483 	pp->p_cwd = dcwd;
484 	dcwd->di_count++;
485 	if (pmaxindex < BIGINDEX)
486 	    pp->p_index = ++pmaxindex;
487 	else {
488 	    struct process *np;
489 
490 	    for (i = 1;; i++) {
491 		for (np = proclist.p_next; np; np = np->p_next)
492 		    if (np->p_index == i)
493 			goto tryagain;
494 		pp->p_index = i;
495 		if (i > pmaxindex)
496 		    pmaxindex = i;
497 		break;
498 	tryagain:;
499 	    }
500 	}
501 	if (pcurrent == NULL)
502 	    pcurrent = pp;
503 	else if (pprevious == NULL)
504 	    pprevious = pp;
505     }
506     pp->p_next = proclist.p_next;
507     proclist.p_next = pp;
508     (void) clock_gettime(CLOCK_MONOTONIC, &pp->p_btime);
509 }
510 
511 static void
512 padd(struct command *t)
513 {
514     Char  **argp;
515 
516     if (t == 0)
517 	return;
518     switch (t->t_dtyp) {
519 
520     case NODE_PAREN:
521 	pads(STRLparensp);
522 	padd(t->t_dspr);
523 	pads(STRspRparen);
524 	break;
525 
526     case NODE_COMMAND:
527 	for (argp = t->t_dcom; *argp; argp++) {
528 	    pads(*argp);
529 	    if (argp[1])
530 		pads(STRspace);
531 	}
532 	break;
533 
534     case NODE_OR:
535     case NODE_AND:
536     case NODE_PIPE:
537     case NODE_LIST:
538 	padd(t->t_dcar);
539 	switch (t->t_dtyp) {
540 	case NODE_OR:
541 	    pads(STRspor2sp);
542 	    break;
543 	case NODE_AND:
544 	    pads(STRspand2sp);
545 	    break;
546 	case NODE_PIPE:
547 	    pads(STRsporsp);
548 	    break;
549 	case NODE_LIST:
550 	    pads(STRsemisp);
551 	    break;
552 	}
553 	padd(t->t_dcdr);
554 	return;
555     }
556     if ((t->t_dflg & F_PIPEIN) == 0 && t->t_dlef) {
557 	pads((t->t_dflg & F_READ) ? STRspLarrow2sp : STRspLarrowsp);
558 	pads(t->t_dlef);
559     }
560     if ((t->t_dflg & F_PIPEOUT) == 0 && t->t_drit) {
561 	pads((t->t_dflg & F_APPEND) ? STRspRarrow2 : STRspRarrow);
562 	if (t->t_dflg & F_STDERR)
563 	    pads(STRand);
564 	pads(STRspace);
565 	pads(t->t_drit);
566     }
567 }
568 
569 static void
570 pads(Char *cp)
571 {
572     int i;
573 
574     /*
575      * Avoid the Quoted Space alias hack! Reported by:
576      * sam@john-bigboote.ICS.UCI.EDU (Sam Horrocks)
577      */
578     if (cp[0] == STRQNULL[0])
579 	cp++;
580 
581     i = Strlen(cp);
582 
583     if (cmdlen >= PMAXLEN)
584 	return;
585     if (cmdlen + i >= PMAXLEN) {
586 	(void) Strlcpy(cmdp, STRsp3dots, PMAXLEN - cmdlen);
587 	cmdlen = PMAXLEN;
588 	cmdp += 4;
589 	return;
590     }
591     (void) Strlcpy(cmdp, cp, PMAXLEN - cmdlen);
592     cmdp += i;
593     cmdlen += i;
594 }
595 
596 /*
597  * psavejob - temporarily save the current job on a one level stack
598  *	so another job can be created.  Used for { } in exp6
599  *	and `` in globbing.
600  */
601 void
602 psavejob(void)
603 {
604 
605     pholdjob = pcurrjob;
606     pcurrjob = NULL;
607 }
608 
609 /*
610  * prestjob - opposite of psavejob.  This may be missed if we are interrupted
611  *	somewhere, but pendjob cleans up anyway.
612  */
613 void
614 prestjob(void)
615 {
616 
617     pcurrjob = pholdjob;
618     pholdjob = NULL;
619 }
620 
621 /*
622  * pendjob - indicate that a job (set of commands) has been completed
623  *	or is about to begin.
624  */
625 void
626 pendjob(void)
627 {
628     struct process *pp, *tp;
629 
630     if (pcurrjob && (pcurrjob->p_flags & (PFOREGND | PSTOPPED)) == 0) {
631 	pp = pcurrjob;
632 	while (pp->p_pid != pp->p_jobid)
633 	    pp = pp->p_friends;
634 	(void) fprintf(cshout, "[%d]", pp->p_index);
635 	tp = pp;
636 	do {
637 	    (void) fprintf(cshout, " %d", pp->p_pid);
638 	    pp = pp->p_friends;
639 	} while (pp != tp);
640 	(void) fputc('\n', cshout);
641     }
642     pholdjob = pcurrjob = 0;
643 }
644 
645 /*
646  * pprint - print a job
647  */
648 static int
649 pprint(struct process *pp, bool flag)
650 {
651     int status, reason;
652     struct process *tp;
653     int     jobflags, pstatus;
654     bool hadnl = 1;	/* did we just have a newline */
655 
656     (void) fpurge(cshout);
657 
658     while (pp->p_pid != pp->p_jobid)
659 	pp = pp->p_friends;
660     if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
661 	pp->p_flags &= ~PPTIME;
662 	pp->p_flags |= PTIME;
663     }
664     tp = pp;
665     status = reason = -1;
666     jobflags = 0;
667     do {
668 	jobflags |= pp->p_flags;
669 	pstatus = pp->p_flags & PALLSTATES;
670 	if (tp != pp && !hadnl && !(flag & FANCY) &&
671 	    ((pstatus == status && pp->p_reason == reason) ||
672 	     !(flag & REASON))) {
673 	    (void) fputc(' ', cshout);
674 	    hadnl = 0;
675 	}
676 	else {
677 	    if (tp != pp && !hadnl) {
678 		(void) fputc('\n', cshout);
679 		hadnl = 1;
680 	    }
681 	    if (flag & NUMBER) {
682 		if (pp == tp)
683 		    (void) fprintf(cshout, "[%d]%s %c ", pp->p_index,
684 			    pp->p_index < 10 ? " " : "",
685 			    pp == pcurrent ? '+' :
686 			    (pp == pprevious ? '-' : ' '));
687 		else
688 		    (void) fprintf(cshout, "       ");
689 		hadnl = 0;
690 	    }
691 	    if (flag & FANCY) {
692 		(void) fprintf(cshout, "%5d ", pp->p_pid);
693 		hadnl = 0;
694 	    }
695 	    if (flag & (REASON | AREASON)) {
696 		int width = 0;
697 		if (flag & NAME)
698 		    width = -23;
699 		if (pstatus == status)
700 		    if (pp->p_reason == reason) {
701 			(void) fprintf(cshout, "%*s", width, "");
702 			hadnl = 0;
703 			goto prcomd;
704 		    }
705 		    else
706 			reason = pp->p_reason;
707 		else {
708 		    status = pstatus;
709 		    reason = pp->p_reason;
710 		}
711 		switch (status) {
712 
713 		case PRUNNING:
714 		    (void) fprintf(cshout, "%*s", width, "Running ");
715 		    hadnl = 0;
716 		    break;
717 
718 		case PINTERRUPTED:
719 		case PSTOPPED:
720 		case PSIGNALED:
721 		    /*
722 		     * tell what happened to the background job
723 		     * From: Michael Schroeder
724 		     * <mlschroe@immd4.informatik.uni-erlangen.de>
725 		     */
726 		    if ((flag & REASON)
727 			|| ((flag & AREASON)
728 			    && reason != SIGINT
729 			    && (reason != SIGPIPE
730 				|| (pp->p_flags & PPOU) == 0))) {
731 			(void) fprintf(cshout, "%*s", width,
732 				       sys_siglist[(unsigned char)
733 						   pp->p_reason]);
734 			hadnl = 0;
735 		    }
736 		    break;
737 
738 		case PNEXITED:
739 		case PAEXITED:
740 		    if (flag & REASON) {
741 			if (pp->p_reason)
742 			    (void) fprintf(cshout, "Exit %-18d", pp->p_reason);
743 			else
744 			    (void) fprintf(cshout, "%*s", width, "Done");
745 			hadnl = 0;
746 		    }
747 		    break;
748 
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(&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     struct timespec tetime, diff;
814     static struct timespec ztime;
815     struct rusage ru;
816     static struct rusage zru;
817     struct process *pp = tp;
818 
819     ru = zru;
820     tetime = ztime;
821     do {
822 	ruadd(&ru, &pp->p_rusage);
823 	timespecsub(&pp->p_etime, &pp->p_btime, &diff);
824 	if (timespeccmp(&diff, &tetime, >))
825 	    tetime = diff;
826     } while ((pp = pp->p_friends) != tp);
827     prusage(&zru, &ru, &tetime, &ztime);
828 }
829 
830 /*
831  * dojobs - print all jobs
832  */
833 void
834 /*ARGSUSED*/
835 dojobs(Char **v, struct command *t)
836 {
837     struct process *pp;
838     int flag = NUMBER | NAME | REASON;
839     int     i;
840 
841     if (chkstop)
842 	chkstop = 2;
843     if (*++v) {
844 	if (v[1] || !eq(*v, STRml))
845 	    stderror(ERR_JOBS);
846 	flag |= FANCY | JOBDIR;
847     }
848     for (i = 1; i <= pmaxindex; i++)
849 	for (pp = proclist.p_next; pp; pp = pp->p_next)
850 	    if (pp->p_index == i && pp->p_pid == pp->p_jobid) {
851 		pp->p_flags &= ~PNEEDNOTE;
852 		if (!(pprint(pp, flag) & (PRUNNING | PSTOPPED)))
853 		    pflush(pp);
854 		break;
855 	    }
856 }
857 
858 /*
859  * dofg - builtin - put the job into the foreground
860  */
861 void
862 /*ARGSUSED*/
863 dofg(Char **v, struct command *t)
864 {
865     struct process *pp;
866 
867     okpcntl();
868     ++v;
869     do {
870 	pp = pfind(*v);
871 	pstart(pp, 1);
872 	pjwait(pp);
873     } while (*v && *++v);
874 }
875 
876 /*
877  * %... - builtin - put the job into the foreground
878  */
879 void
880 /*ARGSUSED*/
881 dofg1(Char **v, struct command *t)
882 {
883     struct process *pp;
884 
885     okpcntl();
886     pp = pfind(v[0]);
887     pstart(pp, 1);
888     pjwait(pp);
889 }
890 
891 /*
892  * dobg - builtin - put the job into the background
893  */
894 void
895 /*ARGSUSED*/
896 dobg(Char **v, struct command *t)
897 {
898     struct process *pp;
899 
900     okpcntl();
901     ++v;
902     do {
903 	pp = pfind(*v);
904 	pstart(pp, 0);
905     } while (*v && *++v);
906 }
907 
908 /*
909  * %... & - builtin - put the job into the background
910  */
911 void
912 /*ARGSUSED*/
913 dobg1(Char **v, struct command *t)
914 {
915     struct process *pp;
916 
917     pp = pfind(v[0]);
918     pstart(pp, 0);
919 }
920 
921 /*
922  * dostop - builtin - stop the job
923  */
924 void
925 /*ARGSUSED*/
926 dostop(Char **v, struct command *t)
927 {
928     pkill(++v, SIGSTOP);
929 }
930 
931 /*
932  * dokill - builtin - superset of kill (1)
933  */
934 void
935 /*ARGSUSED*/
936 dokill(Char **v, struct command *t)
937 {
938     int signum = SIGTERM;
939     const char *errstr;
940     char *name;
941 
942     v++;
943     if (v[0] && v[0][0] == '-') {
944 	if (v[0][1] == 'l') {
945 	    if (v[1]) {
946 		if (!Isdigit(v[1][0]))
947 		    stderror(ERR_NAME | ERR_BADSIG);
948 
949 		signum = strtonum(short2str(v[1]), 0, NSIG-1, &errstr);
950 		if (errstr)
951 		    stderror(ERR_NAME | ERR_BADSIG);
952 		else if (signum == 0)
953 		    (void) fputc('0', cshout); /* 0's symbolic name is '0' */
954 		else
955 		    (void) fprintf(cshout, "%s ", sys_signame[signum]);
956 	    } else {
957 		for (signum = 1; signum < NSIG; signum++) {
958 		    (void) fprintf(cshout, "%s ", sys_signame[signum]);
959 		    if (signum == NSIG / 2)
960 			(void) fputc('\n', cshout);
961 	    	}
962 	    }
963 	    (void) fputc('\n', cshout);
964 	    return;
965 	}
966 	if (Isdigit(v[0][1])) {
967 	    signum = strtonum(short2str(v[0] + 1), 0, NSIG-1, &errstr);
968 	    if (errstr)
969 		stderror(ERR_NAME | ERR_BADSIG);
970 	}
971 	else {
972 	    if (v[0][1] == 's' && (Isspace(v[0][2]) || v[0][2] == '\0')) {
973 		v++;
974 		name = short2str(&v[0][0]);
975 	    } else {
976 		name = short2str(&v[0][1]);
977 	    }
978 
979 	    if (v[0] == NULL || v[1] == NULL) {
980 		stderror(ERR_NAME | ERR_TOOFEW);
981 		return;
982 	    }
983 
984 	    for (signum = 1; signum < NSIG; signum++)
985 		if (!strcasecmp(sys_signame[signum], name) ||
986 		    (strlen(name) > 3 && !strncasecmp("SIG", name, 3) &&
987 		     !strcasecmp(sys_signame[signum], name + 3)))
988 			break;
989 
990 	    if (signum == NSIG) {
991 		if (name[0] == '0')
992 		    signum = 0;
993 		else {
994 		    setname(vis_str(&v[0][0]));
995 		    stderror(ERR_NAME | ERR_UNKSIG);
996 		}
997 	    }
998 	}
999 	v++;
1000     }
1001     pkill(v, signum);
1002 }
1003 
1004 static void
1005 pkill(Char **v, int signum)
1006 {
1007     struct process *pp, *np;
1008     int jobflags = 0;
1009     int     pid, err1 = 0;
1010     sigset_t sigset;
1011     Char   *cp;
1012 
1013     sigemptyset(&sigset);
1014     sigaddset(&sigset, SIGCHLD);
1015     if (setintr)
1016 	sigaddset(&sigset, SIGINT);
1017     sigprocmask(SIG_BLOCK, &sigset, NULL);
1018     gflag = 0, tglob(v);
1019     if (gflag) {
1020 	v = globall(v);
1021 	if (v == 0)
1022 	    stderror(ERR_NAME | ERR_NOMATCH);
1023     }
1024     else {
1025 	v = gargv = saveblk(v);
1026 	trim(v);
1027     }
1028 
1029     while (v && (cp = *v)) {
1030 	if (*cp == '%') {
1031 	    np = pp = pfind(cp);
1032 	    do
1033 		jobflags |= np->p_flags;
1034 	    while ((np = np->p_friends) != pp);
1035 	    switch (signum) {
1036 
1037 	    case SIGSTOP:
1038 	    case SIGTSTP:
1039 	    case SIGTTIN:
1040 	    case SIGTTOU:
1041 		if ((jobflags & PRUNNING) == 0) {
1042 		    (void) fprintf(csherr, "%s: Already suspended\n",
1043 				   vis_str(cp));
1044 		    err1++;
1045 		    goto cont;
1046 		}
1047 		break;
1048 		/*
1049 		 * suspend a process, kill -CONT %, then type jobs; the shell
1050 		 * says it is suspended, but it is running; thanks jaap..
1051 		 */
1052 	    case SIGCONT:
1053 		pstart(pp, 0);
1054 		goto cont;
1055 	    }
1056 	    if (kill(-pp->p_jobid, signum) == -1) {
1057 		(void) fprintf(csherr, "%s: %s\n", vis_str(cp),
1058 			       strerror(errno));
1059 		err1++;
1060 	    }
1061 	    if (signum == SIGTERM || signum == SIGHUP)
1062 		(void) kill(-pp->p_jobid, SIGCONT);
1063 	}
1064 	else if (!(Isdigit(*cp) || *cp == '-'))
1065 	    stderror(ERR_NAME | ERR_JOBARGS);
1066 	else {
1067 	    char *ep;
1068 	    char *pidnam = short2str(cp);
1069 
1070 	    pid = strtol(pidnam, &ep, 10);
1071 	    if (!*pidnam || *ep) {
1072 		(void) fprintf(csherr, "%s: illegal process id\n", pidnam);
1073 		err1++;
1074 		goto cont;
1075 	    }
1076 	    if (kill((pid_t) pid, signum) == -1) {
1077 		(void) fprintf(csherr, "%d: %s\n", pid, strerror(errno));
1078 		err1++;
1079 		goto cont;
1080 	    }
1081 	    if (signum == SIGTERM || signum == SIGHUP)
1082 		(void) kill((pid_t) pid, SIGCONT);
1083 	}
1084 cont:
1085 	v++;
1086     }
1087     blkfree(gargv);
1088     gargv = NULL;
1089     sigprocmask(SIG_UNBLOCK, &sigset, NULL);
1090     if (err1)
1091 	stderror(ERR_SILENT);
1092 }
1093 
1094 /*
1095  * pstart - start the job in foreground/background
1096  */
1097 void
1098 pstart(struct process *pp, int foregnd)
1099 {
1100     struct process *np;
1101     sigset_t sigset, osigset;
1102     long    jobflags = 0;
1103 
1104     sigemptyset(&sigset);
1105     sigaddset(&sigset, SIGCHLD);
1106     sigprocmask(SIG_BLOCK, &sigset, &osigset);
1107     np = pp;
1108     do {
1109 	jobflags |= np->p_flags;
1110 	if (np->p_flags & (PRUNNING | PSTOPPED)) {
1111 	    np->p_flags |= PRUNNING;
1112 	    np->p_flags &= ~PSTOPPED;
1113 	    if (foregnd)
1114 		np->p_flags |= PFOREGND;
1115 	    else
1116 		np->p_flags &= ~PFOREGND;
1117 	}
1118     } while ((np = np->p_friends) != pp);
1119     if (!foregnd)
1120 	pclrcurr(pp);
1121     (void) pprint(pp, foregnd ? NAME | JOBDIR : NUMBER | NAME | AMPERSAND);
1122     if (foregnd)
1123 	(void) tcsetpgrp(FSHTTY, pp->p_jobid);
1124     if (jobflags & PSTOPPED)
1125 	(void) kill(-pp->p_jobid, SIGCONT);
1126     sigprocmask(SIG_SETMASK, &osigset, NULL);
1127 }
1128 
1129 void
1130 panystop(bool neednl)
1131 {
1132     struct process *pp;
1133 
1134     chkstop = 2;
1135     for (pp = proclist.p_next; pp; pp = pp->p_next)
1136 	if (pp->p_flags & PSTOPPED)
1137 	    stderror(ERR_STOPPED, neednl ? "\n" : "");
1138 }
1139 
1140 struct process *
1141 pfind(Char *cp)
1142 {
1143     struct process *pp, *np;
1144 
1145     if (cp == 0 || cp[1] == 0 || eq(cp, STRcent2) || eq(cp, STRcentplus)) {
1146 	if (pcurrent == NULL)
1147 	    stderror(ERR_NAME | ERR_JOBCUR);
1148 	return (pcurrent);
1149     }
1150     if (eq(cp, STRcentminus) || eq(cp, STRcenthash)) {
1151 	if (pprevious == NULL)
1152 	    stderror(ERR_NAME | ERR_JOBPREV);
1153 	return (pprevious);
1154     }
1155     if (Isdigit(cp[1])) {
1156 	const char *errstr;
1157 	int     idx = strtonum(short2str(cp + 1), 1, INT_MAX, &errstr);
1158 
1159 	if (errstr) {
1160 		stderror(ERR_NAME | ERR_NOSUCHJOB);
1161 		return (0);
1162 	}
1163 	for (pp = proclist.p_next; pp; pp = pp->p_next)
1164 	    if (pp->p_index == idx && pp->p_pid == pp->p_jobid)
1165 		return (pp);
1166 	stderror(ERR_NAME | ERR_NOSUCHJOB);
1167 	return (0);
1168     }
1169     np = NULL;
1170     for (pp = proclist.p_next; pp; pp = pp->p_next)
1171 	if (pp->p_pid == pp->p_jobid) {
1172 	    if (cp[1] == '?') {
1173 		Char *dp;
1174 
1175 		for (dp = pp->p_command; *dp; dp++) {
1176 		    if (*dp != cp[2])
1177 			continue;
1178 		    if (prefix(cp + 2, dp))
1179 			goto match;
1180 		}
1181 	    }
1182 	    else if (prefix(cp + 1, pp->p_command)) {
1183 	match:
1184 		if (np)
1185 		    stderror(ERR_NAME | ERR_AMBIG);
1186 		np = pp;
1187 	    }
1188 	}
1189     if (np)
1190 	return (np);
1191     stderror(ERR_NAME | (cp[1] == '?' ? ERR_JOBPAT : ERR_NOSUCHJOB));
1192     /* NOTREACHED */
1193     return (0);
1194 }
1195 
1196 
1197 /*
1198  * pgetcurr - find most recent job that is not pp, preferably stopped
1199  */
1200 static struct process *
1201 pgetcurr(struct process *pp)
1202 {
1203     struct process *np;
1204     struct process *xp = NULL;
1205 
1206     for (np = proclist.p_next; np; np = np->p_next)
1207 	if (np != pcurrent && np != pp && np->p_pid &&
1208 	    np->p_pid == np->p_jobid) {
1209 	    if (np->p_flags & PSTOPPED)
1210 		return (np);
1211 	    if (xp == NULL)
1212 		xp = np;
1213 	}
1214     return (xp);
1215 }
1216 
1217 /*
1218  * donotify - flag the job so as to report termination asynchronously
1219  */
1220 void
1221 /*ARGSUSED*/
1222 donotify(Char **v, struct command *t)
1223 {
1224     struct process *pp;
1225 
1226     pp = pfind(*++v);
1227     pp->p_flags |= PNOTIFY;
1228 }
1229 
1230 /*
1231  * Do the fork and whatever should be done in the child side that
1232  * should not be done if we are not forking at all (like for simple builtin's)
1233  * Also do everything that needs any signals fiddled with in the parent side
1234  *
1235  * Wanttty tells whether process and/or tty pgrps are to be manipulated:
1236  *	-1:	leave tty alone; inherit pgrp from parent
1237  *	 0:	already have tty; manipulate process pgrps only
1238  *	 1:	want to claim tty; manipulate process and tty pgrps
1239  * It is usually just the value of tpgrp.
1240  */
1241 
1242 int
1243 pfork(struct command *t, int wanttty)
1244 {
1245     int pid;
1246     bool    ignint = 0;
1247     int     pgrp;
1248     sigset_t sigset, osigset;
1249 
1250     /*
1251      * A child will be uninterruptible only under very special conditions.
1252      * Remember that the semantics of '&' is implemented by disconnecting the
1253      * process from the tty so signals do not need to ignored just for '&'.
1254      * Thus signals are set to default action for children unless: we have had
1255      * an "onintr -" (then specifically ignored) we are not playing with
1256      * signals (inherit action)
1257      */
1258     if (setintr)
1259 	ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT))
1260 	    || (gointr && eq(gointr, STRminus));
1261     /*
1262      * Check for maximum nesting of 16 processes to avoid Forking loops
1263      */
1264     if (child == 16)
1265 	stderror(ERR_NESTING, 16);
1266     /*
1267      * Hold SIGCHLD until we have the process installed in our table.
1268      */
1269     sigemptyset(&sigset);
1270     sigaddset(&sigset, SIGCHLD);
1271     sigprocmask(SIG_BLOCK, &sigset, &osigset);
1272     while ((pid = fork()) == -1)
1273 	if (setintr == 0)
1274 	    (void) sleep(FORKSLEEP);
1275 	else {
1276 	    sigprocmask(SIG_SETMASK, &osigset, NULL);
1277 	    stderror(ERR_NOPROC);
1278 	}
1279     if (pid == 0) {
1280 	settimes();
1281 	pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
1282 	pflushall();
1283 	pcurrjob = NULL;
1284 	child++;
1285 	if (setintr) {
1286 	    setintr = 0;	/* until I think otherwise */
1287 	    /*
1288 	     * Children just get blown away on SIGINT, SIGQUIT unless "onintr
1289 	     * -" seen.
1290 	     */
1291 	    (void) signal(SIGINT, ignint ? SIG_IGN : SIG_DFL);
1292 	    (void) signal(SIGQUIT, ignint ? SIG_IGN : SIG_DFL);
1293 	    if (wanttty >= 0) {
1294 		/* make stoppable */
1295 		(void) signal(SIGTSTP, SIG_DFL);
1296 		(void) signal(SIGTTIN, SIG_DFL);
1297 		(void) signal(SIGTTOU, SIG_DFL);
1298 	    }
1299 	    (void) signal(SIGTERM, parterm);
1300 	}
1301 	else if (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) {
1302 	    (void) signal(SIGINT, SIG_IGN);
1303 	    (void) signal(SIGQUIT, SIG_IGN);
1304 	}
1305 	pgetty(wanttty, pgrp);
1306 	/*
1307 	 * Nohup and nice apply only to NODE_COMMAND's but it would be nice
1308 	 * (?!?) if you could say "nohup (foo;bar)" Then the parser would have
1309 	 * to know about nice/nohup/time
1310 	 */
1311 	if (t->t_dflg & F_NOHUP)
1312 	    (void) signal(SIGHUP, SIG_IGN);
1313 	if (t->t_dflg & F_NICE)
1314 	    (void) setpriority(PRIO_PROCESS, 0, t->t_nice);
1315     }
1316     else {
1317 	if (wanttty >= 0)
1318 	    (void) setpgid(pid, pcurrjob ? pcurrjob->p_jobid : pid);
1319 	palloc(pid, t);
1320 	sigprocmask(SIG_SETMASK, &osigset, NULL);
1321     }
1322 
1323     return (pid);
1324 }
1325 
1326 static void
1327 okpcntl(void)
1328 {
1329     if (tpgrp == -1)
1330 	stderror(ERR_JOBCONTROL);
1331     if (tpgrp == 0)
1332 	stderror(ERR_JOBCTRLSUB);
1333 }
1334 
1335 /*
1336  * if we don't have vfork(), things can still go in the wrong order
1337  * resulting in the famous 'Stopped (tty output)'. But some systems
1338  * don't permit the setpgid() call, (these are more recent secure
1339  * systems such as ibm's aix). Then we'd rather print an error message
1340  * than hang the shell!
1341  * I am open to suggestions how to fix that.
1342  */
1343 void
1344 pgetty(int wanttty, int pgrp)
1345 {
1346     sigset_t sigset, osigset;
1347 
1348     /*
1349      * christos: I am blocking the tty signals till I've set things
1350      * correctly....
1351      */
1352     if (wanttty > 0) {
1353 	sigemptyset(&sigset);
1354 	sigaddset(&sigset, SIGTSTP);
1355 	sigaddset(&sigset, SIGTTIN);
1356 	sigaddset(&sigset, SIGTTOU);
1357 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
1358     }
1359     /*
1360      * From: Michael Schroeder <mlschroe@immd4.informatik.uni-erlangen.de>
1361      * Don't check for tpgrp >= 0 so even non-interactive shells give
1362      * background jobs process groups Same for the comparison in the other part
1363      * of the #ifdef
1364      */
1365     if (wanttty >= 0)
1366 	if (setpgid(0, pgrp) == -1) {
1367 	    (void) fprintf(csherr, "csh: setpgid error.\n");
1368 	    xexit(0);
1369 	}
1370 
1371     if (wanttty > 0) {
1372 	(void) tcsetpgrp(FSHTTY, pgrp);
1373 	sigprocmask(SIG_SETMASK, &osigset, NULL);
1374     }
1375 
1376     if (tpgrp > 0)
1377 	tpgrp = 0;		/* gave tty away */
1378 }
1379