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proc.c revision 1.9
      1 /*	$NetBSD: proc.c,v 1.9 1995/04/29 23:21:33 mycroft 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #ifndef lint
     37 #if 0
     38 static char sccsid[] = "@(#)proc.c	8.1 (Berkeley) 5/31/93";
     39 #else
     40 static char rcsid[] = "$NetBSD: proc.c,v 1.9 1995/04/29 23:21:33 mycroft Exp $";
     41 #endif
     42 #endif /* not lint */
     43 
     44 #include <sys/types.h>
     45 #include <sys/wait.h>
     46 #include <errno.h>
     47 #include <unistd.h>
     48 #include <stdlib.h>
     49 #include <string.h>
     50 #if __STDC__
     51 # include <stdarg.h>
     52 #else
     53 # include <varargs.h>
     54 #endif
     55 
     56 #include "csh.h"
     57 #include "dir.h"
     58 #include "proc.h"
     59 #include "extern.h"
     60 
     61 #define BIGINDEX	9	/* largest desirable job index */
     62 
     63 static struct rusage zru;
     64 
     65 static void	 pflushall __P((void));
     66 static void	 pflush __P((struct process *));
     67 static void	 pclrcurr __P((struct process *));
     68 static void	 padd __P((struct command *));
     69 static int	 pprint __P((struct process *, int));
     70 static void	 ptprint __P((struct process *));
     71 static void	 pads __P((Char *));
     72 static void	 pkill __P((Char **v, int));
     73 static struct	process
     74 		*pgetcurr __P((struct process *));
     75 static void	 okpcntl __P((void));
     76 
     77 /*
     78  * pchild - called at interrupt level by the SIGCHLD signal
     79  *	indicating that at least one child has terminated or stopped
     80  *	thus at least one wait system call will definitely return a
     81  *	childs status.  Top level routines (like pwait) must be sure
     82  *	to mask interrupts when playing with the proclist data structures!
     83  */
     84 /* ARGUSED */
     85 void
     86 pchild(notused)
     87 	int notused;
     88 {
     89     register struct process *pp;
     90     register struct process *fp;
     91     register int pid;
     92     extern int insource;
     93     union wait w;
     94     int     jobflags;
     95     struct rusage ru;
     96 
     97 loop:
     98     errno = 0;			/* reset, just in case */
     99     pid = wait3(&w.w_status,
    100        (setintr && (intty || insource) ? WNOHANG | WUNTRACED : WNOHANG), &ru);
    101 
    102     if (pid <= 0) {
    103 	if (errno == EINTR) {
    104 	    errno = 0;
    105 	    goto loop;
    106 	}
    107 	pnoprocesses = pid == -1;
    108 	return;
    109     }
    110     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
    111 	if (pid == pp->p_pid)
    112 	    goto found;
    113     goto loop;
    114 found:
    115     if (pid == atoi(short2str(value(STRchild))))
    116 	unsetv(STRchild);
    117     pp->p_flags &= ~(PRUNNING | PSTOPPED | PREPORTED);
    118     if (WIFSTOPPED(w)) {
    119 	pp->p_flags |= PSTOPPED;
    120 	pp->p_reason = w.w_stopsig;
    121     }
    122     else {
    123 	if (pp->p_flags & (PTIME | PPTIME) || adrof(STRtime))
    124 	    (void) gettimeofday(&pp->p_etime, NULL);
    125 
    126 	pp->p_rusage = ru;
    127 	if (WIFSIGNALED(w)) {
    128 	    if (w.w_termsig == SIGINT)
    129 		pp->p_flags |= PINTERRUPTED;
    130 	    else
    131 		pp->p_flags |= PSIGNALED;
    132 	    if (w.w_coredump)
    133 		pp->p_flags |= PDUMPED;
    134 	    pp->p_reason = w.w_termsig;
    135 	}
    136 	else {
    137 	    pp->p_reason = w.w_retcode;
    138 	    if (pp->p_reason != 0)
    139 		pp->p_flags |= PAEXITED;
    140 	    else
    141 		pp->p_flags |= PNEXITED;
    142 	}
    143     }
    144     jobflags = 0;
    145     fp = pp;
    146     do {
    147 	if ((fp->p_flags & (PPTIME | PRUNNING | PSTOPPED)) == 0 &&
    148 	    !child && adrof(STRtime) &&
    149 	    fp->p_rusage.ru_utime.tv_sec + fp->p_rusage.ru_stime.tv_sec
    150 	    >= atoi(short2str(value(STRtime))))
    151 	    fp->p_flags |= PTIME;
    152 	jobflags |= fp->p_flags;
    153     } while ((fp = fp->p_friends) != pp);
    154     pp->p_flags &= ~PFOREGND;
    155     if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
    156 	pp->p_flags &= ~PPTIME;
    157 	pp->p_flags |= PTIME;
    158     }
    159     if ((jobflags & (PRUNNING | PREPORTED)) == 0) {
    160 	fp = pp;
    161 	do {
    162 	    if (fp->p_flags & PSTOPPED)
    163 		fp->p_flags |= PREPORTED;
    164 	} while ((fp = fp->p_friends) != pp);
    165 	while (fp->p_pid != fp->p_jobid)
    166 	    fp = fp->p_friends;
    167 	if (jobflags & PSTOPPED) {
    168 	    if (pcurrent && pcurrent != fp)
    169 		pprevious = pcurrent;
    170 	    pcurrent = fp;
    171 	}
    172 	else
    173 	    pclrcurr(fp);
    174 	if (jobflags & PFOREGND) {
    175 	    if (jobflags & (PSIGNALED | PSTOPPED | PPTIME) ||
    176 #ifdef IIASA
    177 		jobflags & PAEXITED ||
    178 #endif
    179 		!eq(dcwd->di_name, fp->p_cwd->di_name)) {
    180 		;		/* print in pjwait */
    181 	    }
    182 	    /* PWP: print a newline after ^C */
    183 	    else if (jobflags & PINTERRUPTED) {
    184 		(void) vis_fputc('\r' | QUOTE, cshout);
    185 		(void) fputc('\n', cshout);
    186 	    }
    187 	}
    188 	else {
    189 	    if (jobflags & PNOTIFY || adrof(STRnotify)) {
    190 		(void) vis_fputc('\r' | QUOTE, cshout);
    191 		(void) fputc('\n', cshout);
    192 		(void) pprint(pp, NUMBER | NAME | REASON);
    193 		if ((jobflags & PSTOPPED) == 0)
    194 		    pflush(pp);
    195 	    }
    196 	    else {
    197 		fp->p_flags |= PNEEDNOTE;
    198 		neednote++;
    199 	    }
    200 	}
    201     }
    202     goto loop;
    203 }
    204 
    205 void
    206 pnote()
    207 {
    208     register struct process *pp;
    209     int     flags;
    210     sigset_t sigset, osigset;
    211 
    212     neednote = 0;
    213     sigemptyset(&sigset);
    214     sigaddset(&sigset, SIGCHLD);
    215     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next) {
    216 	if (pp->p_flags & PNEEDNOTE) {
    217 	    sigprocmask(SIG_BLOCK, &sigset, &osigset);
    218 	    pp->p_flags &= ~PNEEDNOTE;
    219 	    flags = pprint(pp, NUMBER | NAME | REASON);
    220 	    if ((flags & (PRUNNING | PSTOPPED)) == 0)
    221 		pflush(pp);
    222 	    sigprocmask(SIG_SETMASK, &osigset, NULL);
    223 	}
    224     }
    225 }
    226 
    227 /*
    228  * pwait - wait for current job to terminate, maintaining integrity
    229  *	of current and previous job indicators.
    230  */
    231 void
    232 pwait()
    233 {
    234     register struct process *fp, *pp;
    235     sigset_t sigset, osigset;
    236 
    237     /*
    238      * Here's where dead procs get flushed.
    239      */
    240     sigemptyset(&sigset);
    241     sigaddset(&sigset, SIGCHLD);
    242     sigprocmask(SIG_BLOCK, &sigset, &osigset);
    243     for (pp = (fp = &proclist)->p_next; pp != NULL; pp = (fp = pp)->p_next)
    244 	if (pp->p_pid == 0) {
    245 	    fp->p_next = pp->p_next;
    246 	    xfree((ptr_t) pp->p_command);
    247 	    if (pp->p_cwd && --pp->p_cwd->di_count == 0)
    248 		if (pp->p_cwd->di_next == 0)
    249 		    dfree(pp->p_cwd);
    250 	    xfree((ptr_t) pp);
    251 	    pp = fp;
    252 	}
    253     sigprocmask(SIG_SETMASK, &osigset, NULL);
    254     pjwait(pcurrjob);
    255 }
    256 
    257 
    258 /*
    259  * pjwait - wait for a job to finish or become stopped
    260  *	It is assumed to be in the foreground state (PFOREGND)
    261  */
    262 void
    263 pjwait(pp)
    264     register struct process *pp;
    265 {
    266     register struct process *fp;
    267     int     jobflags, reason;
    268     sigset_t sigset, osigset;
    269 
    270     while (pp->p_pid != pp->p_jobid)
    271 	pp = pp->p_friends;
    272     fp = pp;
    273 
    274     do {
    275 	if ((fp->p_flags & (PFOREGND | PRUNNING)) == PRUNNING)
    276 	    (void) fprintf(csherr, "BUG: waiting for background job!\n");
    277     } while ((fp = fp->p_friends) != pp);
    278     /*
    279      * Now keep pausing as long as we are not interrupted (SIGINT), and the
    280      * target process, or any of its friends, are running
    281      */
    282     fp = pp;
    283     sigemptyset(&sigset);
    284     sigaddset(&sigset, SIGCHLD);
    285     sigprocmask(SIG_BLOCK, &sigset, &osigset);
    286     for (;;) {
    287 	sigemptyset(&sigset);
    288 	sigaddset(&sigset, SIGCHLD);
    289 	sigprocmask(SIG_BLOCK, &sigset, NULL);
    290 	jobflags = 0;
    291 	do
    292 	    jobflags |= fp->p_flags;
    293 	while ((fp = (fp->p_friends)) != pp);
    294 	if ((jobflags & PRUNNING) == 0)
    295 	    break;
    296 #ifdef JOBDEBUG
    297 	(void) fprintf(csherr, "starting to sigsuspend for  SIGCHLD on %d\n",
    298 		       fp->p_pid);
    299 #endif				/* JOBDEBUG */
    300 	sigset = osigset;
    301 	sigdelset(&sigset, SIGCHLD);
    302 	sigsuspend(&sigset);
    303     }
    304     sigprocmask(SIG_SETMASK, &osigset, NULL);
    305     if (tpgrp > 0)		/* get tty back */
    306 	(void) tcsetpgrp(FSHTTY, tpgrp);
    307     if ((jobflags & (PSIGNALED | PSTOPPED | PTIME)) ||
    308 	!eq(dcwd->di_name, fp->p_cwd->di_name)) {
    309 	if (jobflags & PSTOPPED) {
    310 	    (void) fputc('\n', cshout);
    311 	    if (adrof(STRlistjobs)) {
    312 		Char   *jobcommand[3];
    313 
    314 		jobcommand[0] = STRjobs;
    315 		if (eq(value(STRlistjobs), STRlong))
    316 		    jobcommand[1] = STRml;
    317 		else
    318 		    jobcommand[1] = NULL;
    319 		jobcommand[2] = NULL;
    320 
    321 		dojobs(jobcommand, NULL);
    322 		(void) pprint(pp, SHELLDIR);
    323 	    }
    324 	    else
    325 		(void) pprint(pp, AREASON | SHELLDIR);
    326 	}
    327 	else
    328 	    (void) pprint(pp, AREASON | SHELLDIR);
    329     }
    330     if ((jobflags & (PINTERRUPTED | PSTOPPED)) && setintr &&
    331 	(!gointr || !eq(gointr, STRminus))) {
    332 	if ((jobflags & PSTOPPED) == 0)
    333 	    pflush(pp);
    334 	pintr1(0);
    335 	/* NOTREACHED */
    336     }
    337     reason = 0;
    338     fp = pp;
    339     do {
    340 	if (fp->p_reason)
    341 	    reason = fp->p_flags & (PSIGNALED | PINTERRUPTED) ?
    342 		fp->p_reason | META : fp->p_reason;
    343     } while ((fp = fp->p_friends) != pp);
    344     if ((reason != 0) && (adrof(STRprintexitvalue))) {
    345 	(void) fprintf(cshout, "Exit %d\n", reason);
    346     }
    347     set(STRstatus, putn(reason));
    348     if (reason && exiterr)
    349 	exitstat();
    350     pflush(pp);
    351 }
    352 
    353 /*
    354  * dowait - wait for all processes to finish
    355  */
    356 void
    357 /*ARGSUSED*/
    358 dowait(v, t)
    359     Char **v;
    360     struct command *t;
    361 {
    362     register struct process *pp;
    363     sigset_t sigset, osigset;
    364 
    365     pjobs++;
    366     sigemptyset(&sigset);
    367     sigaddset(&sigset, SIGCHLD);
    368     sigprocmask(SIG_BLOCK, &sigset, &osigset);
    369 loop:
    370     for (pp = proclist.p_next; pp; pp = pp->p_next)
    371 	if (pp->p_pid &&	/* pp->p_pid == pp->p_jobid && */
    372 	    pp->p_flags & PRUNNING) {
    373 	    sigemptyset(&sigset);
    374 	    sigsuspend(&sigset);
    375 	    goto loop;
    376 	}
    377     sigprocmask(SIG_SETMASK, &osigset, NULL);
    378     pjobs = 0;
    379 }
    380 
    381 /*
    382  * pflushall - flush all jobs from list (e.g. at fork())
    383  */
    384 static void
    385 pflushall()
    386 {
    387     register struct process *pp;
    388 
    389     for (pp = proclist.p_next; pp != NULL; pp = pp->p_next)
    390 	if (pp->p_pid)
    391 	    pflush(pp);
    392 }
    393 
    394 /*
    395  * pflush - flag all process structures in the same job as the
    396  *	the argument process for deletion.  The actual free of the
    397  *	space is not done here since pflush is called at interrupt level.
    398  */
    399 static void
    400 pflush(pp)
    401     register struct process *pp;
    402 {
    403     register struct process *np;
    404     register int idx;
    405 
    406     if (pp->p_pid == 0) {
    407 	(void) fprintf(csherr, "BUG: process flushed twice");
    408 	return;
    409     }
    410     while (pp->p_pid != pp->p_jobid)
    411 	pp = pp->p_friends;
    412     pclrcurr(pp);
    413     if (pp == pcurrjob)
    414 	pcurrjob = 0;
    415     idx = pp->p_index;
    416     np = pp;
    417     do {
    418 	np->p_index = np->p_pid = 0;
    419 	np->p_flags &= ~PNEEDNOTE;
    420     } while ((np = np->p_friends) != pp);
    421     if (idx == pmaxindex) {
    422 	for (np = proclist.p_next, idx = 0; np; np = np->p_next)
    423 	    if (np->p_index > idx)
    424 		idx = np->p_index;
    425 	pmaxindex = idx;
    426     }
    427 }
    428 
    429 /*
    430  * pclrcurr - make sure the given job is not the current or previous job;
    431  *	pp MUST be the job leader
    432  */
    433 static void
    434 pclrcurr(pp)
    435     register struct process *pp;
    436 {
    437 
    438     if (pp == pcurrent)
    439 	if (pprevious != NULL) {
    440 	    pcurrent = pprevious;
    441 	    pprevious = pgetcurr(pp);
    442 	}
    443 	else {
    444 	    pcurrent = pgetcurr(pp);
    445 	    pprevious = pgetcurr(pp);
    446 	}
    447     else if (pp == pprevious)
    448 	pprevious = pgetcurr(pp);
    449 }
    450 
    451 /* +4 here is 1 for '\0', 1 ea for << >& >> */
    452 static Char command[PMAXLEN + 4];
    453 static int cmdlen;
    454 static Char *cmdp;
    455 
    456 /*
    457  * palloc - allocate a process structure and fill it up.
    458  *	an important assumption is made that the process is running.
    459  */
    460 void
    461 palloc(pid, t)
    462     int     pid;
    463     register struct command *t;
    464 {
    465     register struct process *pp;
    466     int     i;
    467 
    468     pp = (struct process *) xcalloc(1, (size_t) sizeof(struct process));
    469     pp->p_pid = pid;
    470     pp->p_flags = t->t_dflg & F_AMPERSAND ? PRUNNING : PRUNNING | PFOREGND;
    471     if (t->t_dflg & F_TIME)
    472 	pp->p_flags |= PPTIME;
    473     cmdp = command;
    474     cmdlen = 0;
    475     padd(t);
    476     *cmdp++ = 0;
    477     if (t->t_dflg & F_PIPEOUT) {
    478 	pp->p_flags |= PPOU;
    479 	if (t->t_dflg & F_STDERR)
    480 	    pp->p_flags |= PERR;
    481     }
    482     pp->p_command = Strsave(command);
    483     if (pcurrjob) {
    484 	struct process *fp;
    485 
    486 	/* careful here with interrupt level */
    487 	pp->p_cwd = 0;
    488 	pp->p_index = pcurrjob->p_index;
    489 	pp->p_friends = pcurrjob;
    490 	pp->p_jobid = pcurrjob->p_pid;
    491 	for (fp = pcurrjob; fp->p_friends != pcurrjob; fp = fp->p_friends)
    492 	    continue;
    493 	fp->p_friends = pp;
    494     }
    495     else {
    496 	pcurrjob = pp;
    497 	pp->p_jobid = pid;
    498 	pp->p_friends = pp;
    499 	pp->p_cwd = dcwd;
    500 	dcwd->di_count++;
    501 	if (pmaxindex < BIGINDEX)
    502 	    pp->p_index = ++pmaxindex;
    503 	else {
    504 	    struct process *np;
    505 
    506 	    for (i = 1;; i++) {
    507 		for (np = proclist.p_next; np; np = np->p_next)
    508 		    if (np->p_index == i)
    509 			goto tryagain;
    510 		pp->p_index = i;
    511 		if (i > pmaxindex)
    512 		    pmaxindex = i;
    513 		break;
    514 	tryagain:;
    515 	    }
    516 	}
    517 	if (pcurrent == NULL)
    518 	    pcurrent = pp;
    519 	else if (pprevious == NULL)
    520 	    pprevious = pp;
    521     }
    522     pp->p_next = proclist.p_next;
    523     proclist.p_next = pp;
    524     (void) gettimeofday(&pp->p_btime, NULL);
    525 }
    526 
    527 static void
    528 padd(t)
    529     register struct command *t;
    530 {
    531     Char  **argp;
    532 
    533     if (t == 0)
    534 	return;
    535     switch (t->t_dtyp) {
    536 
    537     case NODE_PAREN:
    538 	pads(STRLparensp);
    539 	padd(t->t_dspr);
    540 	pads(STRspRparen);
    541 	break;
    542 
    543     case NODE_COMMAND:
    544 	for (argp = t->t_dcom; *argp; argp++) {
    545 	    pads(*argp);
    546 	    if (argp[1])
    547 		pads(STRspace);
    548 	}
    549 	break;
    550 
    551     case NODE_OR:
    552     case NODE_AND:
    553     case NODE_PIPE:
    554     case NODE_LIST:
    555 	padd(t->t_dcar);
    556 	switch (t->t_dtyp) {
    557 	case NODE_OR:
    558 	    pads(STRspor2sp);
    559 	    break;
    560 	case NODE_AND:
    561 	    pads(STRspand2sp);
    562 	    break;
    563 	case NODE_PIPE:
    564 	    pads(STRsporsp);
    565 	    break;
    566 	case NODE_LIST:
    567 	    pads(STRsemisp);
    568 	    break;
    569 	}
    570 	padd(t->t_dcdr);
    571 	return;
    572     }
    573     if ((t->t_dflg & F_PIPEIN) == 0 && t->t_dlef) {
    574 	pads((t->t_dflg & F_READ) ? STRspLarrow2sp : STRspLarrowsp);
    575 	pads(t->t_dlef);
    576     }
    577     if ((t->t_dflg & F_PIPEOUT) == 0 && t->t_drit) {
    578 	pads((t->t_dflg & F_APPEND) ? STRspRarrow2 : STRspRarrow);
    579 	if (t->t_dflg & F_STDERR)
    580 	    pads(STRand);
    581 	pads(STRspace);
    582 	pads(t->t_drit);
    583     }
    584 }
    585 
    586 static void
    587 pads(cp)
    588     Char   *cp;
    589 {
    590     register int i;
    591 
    592     /*
    593      * Avoid the Quoted Space alias hack! Reported by:
    594      * sam (at) john-bigboote.ICS.UCI.EDU (Sam Horrocks)
    595      */
    596     if (cp[0] == STRQNULL[0])
    597 	cp++;
    598 
    599     i = Strlen(cp);
    600 
    601     if (cmdlen >= PMAXLEN)
    602 	return;
    603     if (cmdlen + i >= PMAXLEN) {
    604 	(void) Strcpy(cmdp, STRsp3dots);
    605 	cmdlen = PMAXLEN;
    606 	cmdp += 4;
    607 	return;
    608     }
    609     (void) Strcpy(cmdp, cp);
    610     cmdp += i;
    611     cmdlen += i;
    612 }
    613 
    614 /*
    615  * psavejob - temporarily save the current job on a one level stack
    616  *	so another job can be created.  Used for { } in exp6
    617  *	and `` in globbing.
    618  */
    619 void
    620 psavejob()
    621 {
    622 
    623     pholdjob = pcurrjob;
    624     pcurrjob = NULL;
    625 }
    626 
    627 /*
    628  * prestjob - opposite of psavejob.  This may be missed if we are interrupted
    629  *	somewhere, but pendjob cleans up anyway.
    630  */
    631 void
    632 prestjob()
    633 {
    634 
    635     pcurrjob = pholdjob;
    636     pholdjob = NULL;
    637 }
    638 
    639 /*
    640  * pendjob - indicate that a job (set of commands) has been completed
    641  *	or is about to begin.
    642  */
    643 void
    644 pendjob()
    645 {
    646     register struct process *pp, *tp;
    647 
    648     if (pcurrjob && (pcurrjob->p_flags & (PFOREGND | PSTOPPED)) == 0) {
    649 	pp = pcurrjob;
    650 	while (pp->p_pid != pp->p_jobid)
    651 	    pp = pp->p_friends;
    652 	(void) fprintf(cshout, "[%d]", pp->p_index);
    653 	tp = pp;
    654 	do {
    655 	    (void) fprintf(cshout, " %d", pp->p_pid);
    656 	    pp = pp->p_friends;
    657 	} while (pp != tp);
    658 	(void) fputc('\n', cshout);
    659     }
    660     pholdjob = pcurrjob = 0;
    661 }
    662 
    663 /*
    664  * pprint - print a job
    665  */
    666 static int
    667 pprint(pp, flag)
    668     register struct process *pp;
    669     bool    flag;
    670 {
    671     register status, reason;
    672     struct process *tp;
    673     int     jobflags, pstatus;
    674     bool hadnl = 1;	/* did we just have a newline */
    675     char   *format;
    676 
    677     (void) fpurge(cshout);
    678 
    679     while (pp->p_pid != pp->p_jobid)
    680 	pp = pp->p_friends;
    681     if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
    682 	pp->p_flags &= ~PPTIME;
    683 	pp->p_flags |= PTIME;
    684     }
    685     tp = pp;
    686     status = reason = -1;
    687     jobflags = 0;
    688     do {
    689 	jobflags |= pp->p_flags;
    690 	pstatus = pp->p_flags & PALLSTATES;
    691 	if (tp != pp && !hadnl && !(flag & FANCY) &&
    692 	    ((pstatus == status && pp->p_reason == reason) ||
    693 	     !(flag & REASON))) {
    694 	    (void) fputc(' ', cshout);
    695 	    hadnl = 0;
    696 	}
    697 	else {
    698 	    if (tp != pp && !hadnl) {
    699 		(void) fputc('\n', cshout);
    700 		hadnl = 1;
    701 	    }
    702 	    if (flag & NUMBER) {
    703 		if (pp == tp)
    704 		    (void) fprintf(cshout, "[%d]%s %c ", pp->p_index,
    705 			    pp->p_index < 10 ? " " : "",
    706 			    pp == pcurrent ? '+' :
    707 			    (pp == pprevious ? '-' : ' '));
    708 		else
    709 		    (void) fprintf(cshout, "       ");
    710 		hadnl = 0;
    711 	    }
    712 	    if (flag & FANCY) {
    713 		(void) fprintf(cshout, "%5d ", pp->p_pid);
    714 		hadnl = 0;
    715 	    }
    716 	    if (flag & (REASON | AREASON)) {
    717 		if (flag & NAME)
    718 		    format = "%-23s";
    719 		else
    720 		    format = "%s";
    721 		if (pstatus == status)
    722 		    if (pp->p_reason == reason) {
    723 			(void) fprintf(cshout, format, "");
    724 			hadnl = 0;
    725 			goto prcomd;
    726 		    }
    727 		    else
    728 			reason = pp->p_reason;
    729 		else {
    730 		    status = pstatus;
    731 		    reason = pp->p_reason;
    732 		}
    733 		switch (status) {
    734 
    735 		case PRUNNING:
    736 		    (void) fprintf(cshout, format, "Running ");
    737 		    hadnl = 0;
    738 		    break;
    739 
    740 		case PINTERRUPTED:
    741 		case PSTOPPED:
    742 		case PSIGNALED:
    743                     /*
    744                      * tell what happened to the background job
    745                      * From: Michael Schroeder
    746                      * <mlschroe (at) immd4.informatik.uni-erlangen.de>
    747                      */
    748                     if ((flag & REASON)
    749                         || ((flag & AREASON)
    750                             && reason != SIGINT
    751                             && (reason != SIGPIPE
    752                                 || (pp->p_flags & PPOU) == 0))) {
    753 			(void) fprintf(cshout, format,
    754 				       sys_siglist[(unsigned char)
    755 						   pp->p_reason]);
    756 			hadnl = 0;
    757 		    }
    758 		    break;
    759 
    760 		case PNEXITED:
    761 		case PAEXITED:
    762 		    if (flag & REASON) {
    763 			if (pp->p_reason)
    764 			    (void) fprintf(cshout, "Exit %-18d", pp->p_reason);
    765 			else
    766 			    (void) fprintf(cshout, format, "Done");
    767 			hadnl = 0;
    768 		    }
    769 		    break;
    770 
    771 		default:
    772 		    (void) fprintf(csherr, "BUG: status=%-9o", status);
    773 		}
    774 	    }
    775 	}
    776 prcomd:
    777 	if (flag & NAME) {
    778 	    (void) fprintf(cshout, "%s", vis_str(pp->p_command));
    779 	    if (pp->p_flags & PPOU)
    780 		(void) fprintf(cshout, " |");
    781 	    if (pp->p_flags & PERR)
    782 		(void) fputc('&', cshout);
    783 	    hadnl = 0;
    784 	}
    785 	if (flag & (REASON | AREASON) && pp->p_flags & PDUMPED) {
    786 	    (void) fprintf(cshout, " (core dumped)");
    787 	    hadnl = 0;
    788 	}
    789 	if (tp == pp->p_friends) {
    790 	    if (flag & AMPERSAND) {
    791 		(void) fprintf(cshout, " &");
    792 		hadnl = 0;
    793 	    }
    794 	    if (flag & JOBDIR &&
    795 		!eq(tp->p_cwd->di_name, dcwd->di_name)) {
    796 		(void) fprintf(cshout, " (wd: ");
    797 		dtildepr(value(STRhome), tp->p_cwd->di_name);
    798 		(void) fputc(')', cshout);
    799 		hadnl = 0;
    800 	    }
    801 	}
    802 	if (pp->p_flags & PPTIME && !(status & (PSTOPPED | PRUNNING))) {
    803 	    if (!hadnl)
    804 		(void) fprintf(cshout, "\n\t");
    805 	    prusage(&zru, &pp->p_rusage, &pp->p_etime,
    806 		    &pp->p_btime);
    807 	    hadnl = 1;
    808 	}
    809 	if (tp == pp->p_friends) {
    810 	    if (!hadnl) {
    811 		(void) fputc('\n', cshout);
    812 		hadnl = 1;
    813 	    }
    814 	    if (flag & SHELLDIR && !eq(tp->p_cwd->di_name, dcwd->di_name)) {
    815 		(void) fprintf(cshout, "(wd now: ");
    816 		dtildepr(value(STRhome), dcwd->di_name);
    817 		(void) fprintf(cshout, ")\n");
    818 		hadnl = 1;
    819 	    }
    820 	}
    821     } while ((pp = pp->p_friends) != tp);
    822     if (jobflags & PTIME && (jobflags & (PSTOPPED | PRUNNING)) == 0) {
    823 	if (jobflags & NUMBER)
    824 	    (void) fprintf(cshout, "       ");
    825 	ptprint(tp);
    826 	hadnl = 1;
    827     }
    828     (void) fflush(cshout);
    829     return (jobflags);
    830 }
    831 
    832 static void
    833 ptprint(tp)
    834     register struct process *tp;
    835 {
    836     struct timeval tetime, diff;
    837     static struct timeval ztime;
    838     struct rusage ru;
    839     static struct rusage zru;
    840     register struct process *pp = tp;
    841 
    842     ru = zru;
    843     tetime = ztime;
    844     do {
    845 	ruadd(&ru, &pp->p_rusage);
    846 	timersub(&pp->p_etime, &pp->p_btime, &diff);
    847 	if (timercmp(&diff, &tetime, >))
    848 	    tetime = diff;
    849     } while ((pp = pp->p_friends) != tp);
    850     prusage(&zru, &ru, &tetime, &ztime);
    851 }
    852 
    853 /*
    854  * dojobs - print all jobs
    855  */
    856 void
    857 /*ARGSUSED*/
    858 dojobs(v, t)
    859     Char **v;
    860     struct command *t;
    861 {
    862     register struct process *pp;
    863     register int flag = NUMBER | NAME | REASON;
    864     int     i;
    865 
    866     if (chkstop)
    867 	chkstop = 2;
    868     if (*++v) {
    869 	if (v[1] || !eq(*v, STRml))
    870 	    stderror(ERR_JOBS);
    871 	flag |= FANCY | JOBDIR;
    872     }
    873     for (i = 1; i <= pmaxindex; i++)
    874 	for (pp = proclist.p_next; pp; pp = pp->p_next)
    875 	    if (pp->p_index == i && pp->p_pid == pp->p_jobid) {
    876 		pp->p_flags &= ~PNEEDNOTE;
    877 		if (!(pprint(pp, flag) & (PRUNNING | PSTOPPED)))
    878 		    pflush(pp);
    879 		break;
    880 	    }
    881 }
    882 
    883 /*
    884  * dofg - builtin - put the job into the foreground
    885  */
    886 void
    887 /*ARGSUSED*/
    888 dofg(v, t)
    889     Char **v;
    890     struct command *t;
    891 {
    892     register struct process *pp;
    893 
    894     okpcntl();
    895     ++v;
    896     do {
    897 	pp = pfind(*v);
    898 	pstart(pp, 1);
    899 	pjwait(pp);
    900     } while (*v && *++v);
    901 }
    902 
    903 /*
    904  * %... - builtin - put the job into the foreground
    905  */
    906 void
    907 /*ARGSUSED*/
    908 dofg1(v, t)
    909     Char **v;
    910     struct command *t;
    911 {
    912     register struct process *pp;
    913 
    914     okpcntl();
    915     pp = pfind(v[0]);
    916     pstart(pp, 1);
    917     pjwait(pp);
    918 }
    919 
    920 /*
    921  * dobg - builtin - put the job into the background
    922  */
    923 void
    924 /*ARGSUSED*/
    925 dobg(v, t)
    926     Char **v;
    927     struct command *t;
    928 {
    929     register struct process *pp;
    930 
    931     okpcntl();
    932     ++v;
    933     do {
    934 	pp = pfind(*v);
    935 	pstart(pp, 0);
    936     } while (*v && *++v);
    937 }
    938 
    939 /*
    940  * %... & - builtin - put the job into the background
    941  */
    942 void
    943 /*ARGSUSED*/
    944 dobg1(v, t)
    945     Char **v;
    946     struct command *t;
    947 {
    948     register struct process *pp;
    949 
    950     pp = pfind(v[0]);
    951     pstart(pp, 0);
    952 }
    953 
    954 /*
    955  * dostop - builtin - stop the job
    956  */
    957 void
    958 /*ARGSUSED*/
    959 dostop(v, t)
    960     Char **v;
    961     struct command *t;
    962 {
    963     pkill(++v, SIGSTOP);
    964 }
    965 
    966 /*
    967  * dokill - builtin - superset of kill (1)
    968  */
    969 void
    970 /*ARGSUSED*/
    971 dokill(v, t)
    972     Char **v;
    973     struct command *t;
    974 {
    975     register int signum = SIGTERM;
    976     register char *name;
    977 
    978     v++;
    979     if (v[0] && v[0][0] == '-') {
    980 	if (v[0][1] == 'l') {
    981 	    for (signum = 1; signum < NSIG; signum++) {
    982 		(void) fprintf(cshout, "%s ", sys_signame[signum]);
    983 		if (signum == NSIG / 2)
    984 		    (void) fputc('\n', cshout);
    985 	    }
    986 	    (void) fputc('\n', cshout);
    987 	    return;
    988 	}
    989 	if (Isdigit(v[0][1])) {
    990 	    signum = atoi(short2str(v[0] + 1));
    991 	    if (signum < 0 || signum > NSIG)
    992 		stderror(ERR_NAME | ERR_BADSIG);
    993 	}
    994 	else {
    995 	    name = short2str(&v[0][1]);
    996 	    if (!strncasecmp(name, "sig", 3))
    997 		name += 3;
    998 
    999 	    for (signum = 1; signum < NSIG; signum++)
   1000 		if (!strcasecmp(sys_signame[signum], name))
   1001 		    break;
   1002 
   1003 	    if (signum == NSIG) {
   1004 		setname(vis_str(&v[0][1]));
   1005 		stderror(ERR_NAME | ERR_UNKSIG);
   1006 	    }
   1007 	}
   1008 	v++;
   1009     }
   1010     pkill(v, signum);
   1011 }
   1012 
   1013 static void
   1014 pkill(v, signum)
   1015     Char  **v;
   1016     int     signum;
   1017 {
   1018     register struct process *pp, *np;
   1019     register int jobflags = 0;
   1020     int     pid, err1 = 0;
   1021     sigset_t sigset;
   1022     Char   *cp;
   1023 
   1024     sigemptyset(&sigset);
   1025     sigaddset(&sigset, SIGCHLD);
   1026     if (setintr)
   1027 	sigaddset(&sigset, SIGINT);
   1028     sigprocmask(SIG_BLOCK, &sigset, NULL);
   1029     gflag = 0, tglob(v);
   1030     if (gflag) {
   1031 	v = globall(v);
   1032 	if (v == 0)
   1033 	    stderror(ERR_NAME | ERR_NOMATCH);
   1034     }
   1035     else {
   1036 	v = gargv = saveblk(v);
   1037 	trim(v);
   1038     }
   1039 
   1040     while (v && (cp = *v)) {
   1041 	if (*cp == '%') {
   1042 	    np = pp = pfind(cp);
   1043 	    do
   1044 		jobflags |= np->p_flags;
   1045 	    while ((np = np->p_friends) != pp);
   1046 	    switch (signum) {
   1047 
   1048 	    case SIGSTOP:
   1049 	    case SIGTSTP:
   1050 	    case SIGTTIN:
   1051 	    case SIGTTOU:
   1052 		if ((jobflags & PRUNNING) == 0) {
   1053 		    (void) fprintf(csherr, "%s: Already suspended\n",
   1054 				   vis_str(cp));
   1055 		    err1++;
   1056 		    goto cont;
   1057 		}
   1058 		break;
   1059 		/*
   1060 		 * suspend a process, kill -CONT %, then type jobs; the shell
   1061 		 * says it is suspended, but it is running; thanks jaap..
   1062 		 */
   1063 	    case SIGCONT:
   1064 		pstart(pp, 0);
   1065 		goto cont;
   1066 	    }
   1067 	    if (kill(-pp->p_jobid, signum) < 0) {
   1068 		(void) fprintf(csherr, "%s: %s\n", vis_str(cp),
   1069 			       strerror(errno));
   1070 		err1++;
   1071 	    }
   1072 	    if (signum == SIGTERM || signum == SIGHUP)
   1073 		(void) kill(-pp->p_jobid, SIGCONT);
   1074 	}
   1075 	else if (!(Isdigit(*cp) || *cp == '-'))
   1076 	    stderror(ERR_NAME | ERR_JOBARGS);
   1077 	else {
   1078 	    pid = atoi(short2str(cp));
   1079 	    if (kill((pid_t) pid, signum) < 0) {
   1080 		(void) fprintf(csherr, "%d: %s\n", pid, strerror(errno));
   1081 		err1++;
   1082 		goto cont;
   1083 	    }
   1084 	    if (signum == SIGTERM || signum == SIGHUP)
   1085 		(void) kill((pid_t) pid, SIGCONT);
   1086 	}
   1087 cont:
   1088 	v++;
   1089     }
   1090     if (gargv)
   1091 	blkfree(gargv), gargv = 0;
   1092     sigprocmask(SIG_UNBLOCK, &sigset, NULL);
   1093     if (err1)
   1094 	stderror(ERR_SILENT);
   1095 }
   1096 
   1097 /*
   1098  * pstart - start the job in foreground/background
   1099  */
   1100 void
   1101 pstart(pp, foregnd)
   1102     register struct process *pp;
   1103     int     foregnd;
   1104 {
   1105     register struct process *np;
   1106     sigset_t sigset, osigset;
   1107     long    jobflags = 0;
   1108 
   1109     sigemptyset(&sigset);
   1110     sigaddset(&sigset, SIGCHLD);
   1111     sigprocmask(SIG_BLOCK, &sigset, &osigset);
   1112     np = pp;
   1113     do {
   1114 	jobflags |= np->p_flags;
   1115 	if (np->p_flags & (PRUNNING | PSTOPPED)) {
   1116 	    np->p_flags |= PRUNNING;
   1117 	    np->p_flags &= ~PSTOPPED;
   1118 	    if (foregnd)
   1119 		np->p_flags |= PFOREGND;
   1120 	    else
   1121 		np->p_flags &= ~PFOREGND;
   1122 	}
   1123     } while ((np = np->p_friends) != pp);
   1124     if (!foregnd)
   1125 	pclrcurr(pp);
   1126     (void) pprint(pp, foregnd ? NAME | JOBDIR : NUMBER | NAME | AMPERSAND);
   1127     if (foregnd)
   1128 	(void) tcsetpgrp(FSHTTY, pp->p_jobid);
   1129     if (jobflags & PSTOPPED)
   1130 	(void) kill(-pp->p_jobid, SIGCONT);
   1131     sigprocmask(SIG_SETMASK, &osigset, NULL);
   1132 }
   1133 
   1134 void
   1135 panystop(neednl)
   1136     bool    neednl;
   1137 {
   1138     register struct process *pp;
   1139 
   1140     chkstop = 2;
   1141     for (pp = proclist.p_next; pp; pp = pp->p_next)
   1142 	if (pp->p_flags & PSTOPPED)
   1143 	    stderror(ERR_STOPPED, neednl ? "\n" : "");
   1144 }
   1145 
   1146 struct process *
   1147 pfind(cp)
   1148     Char   *cp;
   1149 {
   1150     register struct process *pp, *np;
   1151 
   1152     if (cp == 0 || cp[1] == 0 || eq(cp, STRcent2) || eq(cp, STRcentplus)) {
   1153 	if (pcurrent == NULL)
   1154 	    stderror(ERR_NAME | ERR_JOBCUR);
   1155 	return (pcurrent);
   1156     }
   1157     if (eq(cp, STRcentminus) || eq(cp, STRcenthash)) {
   1158 	if (pprevious == NULL)
   1159 	    stderror(ERR_NAME | ERR_JOBPREV);
   1160 	return (pprevious);
   1161     }
   1162     if (Isdigit(cp[1])) {
   1163 	int     idx = atoi(short2str(cp + 1));
   1164 
   1165 	for (pp = proclist.p_next; pp; pp = pp->p_next)
   1166 	    if (pp->p_index == idx && pp->p_pid == pp->p_jobid)
   1167 		return (pp);
   1168 	stderror(ERR_NAME | ERR_NOSUCHJOB);
   1169     }
   1170     np = NULL;
   1171     for (pp = proclist.p_next; pp; pp = pp->p_next)
   1172 	if (pp->p_pid == pp->p_jobid) {
   1173 	    if (cp[1] == '?') {
   1174 		register Char *dp;
   1175 
   1176 		for (dp = pp->p_command; *dp; dp++) {
   1177 		    if (*dp != cp[2])
   1178 			continue;
   1179 		    if (prefix(cp + 2, dp))
   1180 			goto match;
   1181 		}
   1182 	    }
   1183 	    else if (prefix(cp + 1, pp->p_command)) {
   1184 	match:
   1185 		if (np)
   1186 		    stderror(ERR_NAME | ERR_AMBIG);
   1187 		np = pp;
   1188 	    }
   1189 	}
   1190     if (np)
   1191 	return (np);
   1192     stderror(ERR_NAME | cp[1] == '?' ? ERR_JOBPAT : ERR_NOSUCHJOB);
   1193     /* NOTREACHED */
   1194     return (0);
   1195 }
   1196 
   1197 
   1198 /*
   1199  * pgetcurr - find most recent job that is not pp, preferably stopped
   1200  */
   1201 static struct process *
   1202 pgetcurr(pp)
   1203     register struct process *pp;
   1204 {
   1205     register struct process *np;
   1206     register struct process *xp = NULL;
   1207 
   1208     for (np = proclist.p_next; np; np = np->p_next)
   1209 	if (np != pcurrent && np != pp && np->p_pid &&
   1210 	    np->p_pid == np->p_jobid) {
   1211 	    if (np->p_flags & PSTOPPED)
   1212 		return (np);
   1213 	    if (xp == NULL)
   1214 		xp = np;
   1215 	}
   1216     return (xp);
   1217 }
   1218 
   1219 /*
   1220  * donotify - flag the job so as to report termination asynchronously
   1221  */
   1222 void
   1223 /*ARGSUSED*/
   1224 donotify(v, t)
   1225     Char **v;
   1226     struct command *t;
   1227 {
   1228     register struct process *pp;
   1229 
   1230     pp = pfind(*++v);
   1231     pp->p_flags |= PNOTIFY;
   1232 }
   1233 
   1234 /*
   1235  * Do the fork and whatever should be done in the child side that
   1236  * should not be done if we are not forking at all (like for simple builtin's)
   1237  * Also do everything that needs any signals fiddled with in the parent side
   1238  *
   1239  * Wanttty tells whether process and/or tty pgrps are to be manipulated:
   1240  *	-1:	leave tty alone; inherit pgrp from parent
   1241  *	 0:	already have tty; manipulate process pgrps only
   1242  *	 1:	want to claim tty; manipulate process and tty pgrps
   1243  * It is usually just the value of tpgrp.
   1244  */
   1245 
   1246 int
   1247 pfork(t, wanttty)
   1248     struct command *t;		/* command we are forking for */
   1249     int     wanttty;
   1250 {
   1251     register int pid;
   1252     bool    ignint = 0;
   1253     int     pgrp;
   1254     sigset_t sigset, osigset;
   1255 
   1256     /*
   1257      * A child will be uninterruptible only under very special conditions.
   1258      * Remember that the semantics of '&' is implemented by disconnecting the
   1259      * process from the tty so signals do not need to ignored just for '&'.
   1260      * Thus signals are set to default action for children unless: we have had
   1261      * an "onintr -" (then specifically ignored) we are not playing with
   1262      * signals (inherit action)
   1263      */
   1264     if (setintr)
   1265 	ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT))
   1266 	    || (gointr && eq(gointr, STRminus));
   1267     /*
   1268      * Check for maximum nesting of 16 processes to avoid Forking loops
   1269      */
   1270     if (child == 16)
   1271 	stderror(ERR_NESTING, 16);
   1272     /*
   1273      * Hold SIGCHLD until we have the process installed in our table.
   1274      */
   1275     sigemptyset(&sigset);
   1276     sigaddset(&sigset, SIGCHLD);
   1277     sigprocmask(SIG_BLOCK, &sigset, &osigset);
   1278     while ((pid = fork()) < 0)
   1279 	if (setintr == 0)
   1280 	    (void) sleep(FORKSLEEP);
   1281 	else {
   1282 	    sigprocmask(SIG_SETMASK, &osigset, NULL);
   1283 	    stderror(ERR_NOPROC);
   1284 	}
   1285     if (pid == 0) {
   1286 	settimes();
   1287 	pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
   1288 	pflushall();
   1289 	pcurrjob = NULL;
   1290 	child++;
   1291 	if (setintr) {
   1292 	    setintr = 0;	/* until I think otherwise */
   1293 	    /*
   1294 	     * Children just get blown away on SIGINT, SIGQUIT unless "onintr
   1295 	     * -" seen.
   1296 	     */
   1297 	    (void) signal(SIGINT, ignint ? SIG_IGN : SIG_DFL);
   1298 	    (void) signal(SIGQUIT, ignint ? SIG_IGN : SIG_DFL);
   1299 	    if (wanttty >= 0) {
   1300 		/* make stoppable */
   1301 		(void) signal(SIGTSTP, SIG_DFL);
   1302 		(void) signal(SIGTTIN, SIG_DFL);
   1303 		(void) signal(SIGTTOU, SIG_DFL);
   1304 	    }
   1305 	    (void) signal(SIGTERM, parterm);
   1306 	}
   1307 	else if (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) {
   1308 	    (void) signal(SIGINT, SIG_IGN);
   1309 	    (void) signal(SIGQUIT, SIG_IGN);
   1310 	}
   1311 	pgetty(wanttty, pgrp);
   1312 	/*
   1313 	 * Nohup and nice apply only to NODE_COMMAND's but it would be nice
   1314 	 * (?!?) if you could say "nohup (foo;bar)" Then the parser would have
   1315 	 * to know about nice/nohup/time
   1316 	 */
   1317 	if (t->t_dflg & F_NOHUP)
   1318 	    (void) signal(SIGHUP, SIG_IGN);
   1319 	if (t->t_dflg & F_NICE)
   1320 	    (void) setpriority(PRIO_PROCESS, 0, t->t_nice);
   1321     }
   1322     else {
   1323 	if (wanttty >= 0)
   1324 	    (void) setpgid(pid, pcurrjob ? pcurrjob->p_jobid : pid);
   1325 	palloc(pid, t);
   1326 	sigprocmask(SIG_SETMASK, &osigset, NULL);
   1327     }
   1328 
   1329     return (pid);
   1330 }
   1331 
   1332 static void
   1333 okpcntl()
   1334 {
   1335     if (tpgrp == -1)
   1336 	stderror(ERR_JOBCONTROL);
   1337     if (tpgrp == 0)
   1338 	stderror(ERR_JOBCTRLSUB);
   1339 }
   1340 
   1341 /*
   1342  * if we don't have vfork(), things can still go in the wrong order
   1343  * resulting in the famous 'Stopped (tty output)'. But some systems
   1344  * don't permit the setpgid() call, (these are more recent secure
   1345  * systems such as ibm's aix). Then we'd rather print an error message
   1346  * than hang the shell!
   1347  * I am open to suggestions how to fix that.
   1348  */
   1349 void
   1350 pgetty(wanttty, pgrp)
   1351     int     wanttty, pgrp;
   1352 {
   1353     sigset_t sigset, osigset;
   1354 
   1355     /*
   1356      * christos: I am blocking the tty signals till I've set things
   1357      * correctly....
   1358      */
   1359     if (wanttty > 0) {
   1360 	sigemptyset(&sigset);
   1361 	sigaddset(&sigset, SIGTSTP);
   1362 	sigaddset(&sigset, SIGTTIN);
   1363 	sigaddset(&sigset, SIGTTOU);
   1364 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
   1365     }
   1366     /*
   1367      * From: Michael Schroeder <mlschroe (at) immd4.informatik.uni-erlangen.de>
   1368      * Don't check for tpgrp >= 0 so even non-interactive shells give
   1369      * background jobs process groups Same for the comparison in the other part
   1370      * of the #ifdef
   1371      */
   1372     if (wanttty >= 0)
   1373 	if (setpgid(0, pgrp) == -1) {
   1374 	    (void) fprintf(csherr, "csh: setpgid error.\n");
   1375 	    xexit(0);
   1376 	}
   1377 
   1378     if (wanttty > 0) {
   1379 	(void) tcsetpgrp(FSHTTY, pgrp);
   1380 	sigprocmask(SIG_SETMASK, &osigset, NULL);
   1381     }
   1382 
   1383     if (tpgrp > 0)
   1384 	tpgrp = 0;		/* gave tty away */
   1385 }
   1386