auto import from //depot/cupcake/@135843

1 files changed, 1487 insertions, 0 deletions

diff --git a/sh/jobs.c b/sh/jobs.c
new file mode 100644
index 00000000..b9460b03
--- /dev/null
+++ b/sh/jobs.c
@@ -0,0 +1,1487 @@
+/*	$NetBSD: jobs.c,v 1.62 2003/12/18 00:56:05 christos Exp $	*/
+
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)jobs.c	8.5 (Berkeley) 5/4/95";
+#else
+__RCSID("$NetBSD: jobs.c,v 1.62 2003/12/18 00:56:05 christos Exp $");
+#endif
+#endif /* not lint */
+
+#include <fcntl.h>
+#include <signal.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#define _PATH_DEVNULL "/dev/null"
+#include <sys/types.h>
+#include <sys/param.h>
+#ifdef BSD
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif
+#include <sys/wait.h>
+#define killpg(s,i) kill(-(s),i)
+#include <sys/ioctl.h>
+
+#include "shell.h"
+#if JOBS
+#if OLD_TTY_DRIVER
+#include "sgtty.h"
+#else
+#include <termios.h>
+#endif
+#undef CEOF			/* syntax.h redefines this */
+#endif
+#include "redir.h"
+#include "show.h"
+#include "main.h"
+#include "parser.h"
+#include "nodes.h"
+#include "jobs.h"
+#include "options.h"
+#include "trap.h"
+#include "syntax.h"
+#include "input.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mystring.h"
+
+// Use of process groups is disabled to allow adb shell children to terminate when the shell dies
+#define USE_PROCESS_GROUPS
+
+
+static struct job *jobtab;		/* array of jobs */
+static int njobs;			/* size of array */
+static int jobs_invalid;		/* set in child */
+MKINIT pid_t backgndpid = -1;	/* pid of last background process */
+#if JOBS
+int initialpgrp;		/* pgrp of shell on invocation */
+static int curjob = -1;		/* current job */
+#endif
+static int ttyfd = -1;
+
+STATIC void restartjob(struct job *);
+STATIC void freejob(struct job *);
+STATIC struct job *getjob(const char *, int);
+STATIC int dowait(int, struct job *);
+STATIC int onsigchild(void);
+STATIC int waitproc(int, struct job *, int *);
+STATIC void cmdtxt(union node *);
+STATIC void cmdlist(union node *, int);
+STATIC void cmdputs(const char *);
+
+#ifdef OLD_TTY_DRIVER
+static pid_t tcgetpgrp(int fd);
+static int tcsetpgrp(int fd, pid_t pgrp);
+
+static pid_t
+tcgetpgrp(int fd)
+{
+	pid_t pgrp;
+	if (ioctl(fd, TIOCGPGRP, (char *)&pgrp) == -1)
+		return -1;
+	else
+		return pgrp;
+}
+
+static int
+tcsetpgrp(int fd, pid_tpgrp)
+{
+	return ioctl(fd, TIOCSPGRP, (char *)&pgrp);
+}
+#endif
+
+/*
+ * Turn job control on and off.
+ *
+ * Note:  This code assumes that the third arg to ioctl is a character
+ * pointer, which is true on Berkeley systems but not System V.  Since
+ * System V doesn't have job control yet, this isn't a problem now.
+ */
+
+MKINIT int jobctl;
+
+void
+setjobctl(int on)
+{
+#ifdef OLD_TTY_DRIVER
+	int ldisc;
+#endif
+
+	if (on == jobctl || rootshell == 0)
+		return;
+	if (on) {
+#if defined(FIOCLEX) || defined(FD_CLOEXEC)
+		int err;
+		int i;
+		if (ttyfd != -1)
+			close(ttyfd);
+		if ((ttyfd = open("/dev/tty", O_RDWR)) == -1) {
+			for (i = 0; i < 3; i++) {
+				if (isatty(i) && (ttyfd = dup(i)) != -1)
+					break;
+			}
+			if (i == 3)
+				goto out;
+		}
+		/* Move to a high fd */
+		for (i = 10; i > 2; i--) {
+			if ((err = fcntl(ttyfd, F_DUPFD, (1 << i) - 1)) != -1)
+				break;
+		}
+		if (err != -1) {
+			close(ttyfd);
+			ttyfd = err;
+		}
+#ifdef FIOCLEX
+		err = ioctl(ttyfd, FIOCLEX, 0);
+#elif FD_CLOEXEC
+		err = fcntl(ttyfd, F_SETFD,
+		    fcntl(ttyfd, F_GETFD, 0) | FD_CLOEXEC);
+#endif
+		if (err == -1) {
+			close(ttyfd);
+			ttyfd = -1;
+			goto out;
+		}
+#else
+		out2str("sh: Need FIOCLEX or FD_CLOEXEC to support job control");
+		goto out;
+#endif
+		do { /* while we are in the background */
+			if ((initialpgrp = tcgetpgrp(ttyfd)) < 0) {
+out:
+				out2str("sh: can't access tty; job control turned off\n");
+				mflag = 0;
+				return;
+			}
+			if (initialpgrp == -1)
+				initialpgrp = getpgrp();
+			else if (initialpgrp != getpgrp()) {
+				killpg(0, SIGTTIN);
+				continue;
+			}
+		} while (0);
+
+#ifdef OLD_TTY_DRIVER
+		if (ioctl(ttyfd, TIOCGETD, (char *)&ldisc) < 0
+		    || ldisc != NTTYDISC) {
+			out2str("sh: need new tty driver to run job control; job control turned off\n");
+			mflag = 0;
+			return;
+		}
+#endif
+		setsignal(SIGTSTP, 0);
+		setsignal(SIGTTOU, 0);
+		setsignal(SIGTTIN, 0);
+#ifdef USE_PROCESS_GROUPS
+		if (getpgid(0) != rootpid && setpgid(0, rootpid) == -1)
+			error("Cannot set process group (%s) at %d",
+			    strerror(errno), __LINE__);
+		if (tcsetpgrp(ttyfd, rootpid) == -1)
+			error("Cannot set tty process group (%s) at %d",
+			    strerror(errno), __LINE__);
+#endif
+	} else { /* turning job control off */
+#ifdef USE_PROCESS_GROUPS
+		if (getpgid(0) != initialpgrp && setpgid(0, initialpgrp) == -1)
+			error("Cannot set process group (%s) at %d",
+			    strerror(errno), __LINE__);
+		if (tcsetpgrp(ttyfd, initialpgrp) == -1)
+			error("Cannot set tty process group (%s) at %d",
+			    strerror(errno), __LINE__);
+#endif
+		close(ttyfd);
+		ttyfd = -1;
+		setsignal(SIGTSTP, 0);
+		setsignal(SIGTTOU, 0);
+		setsignal(SIGTTIN, 0);
+	}
+	jobctl = on;
+}
+
+
+#ifdef mkinit
+INCLUDE <stdlib.h>
+
+SHELLPROC {
+	backgndpid = -1;
+#if JOBS
+	jobctl = 0;
+#endif
+}
+
+#endif
+
+
+
+#if JOBS
+int
+fgcmd(int argc, char **argv)
+{
+	struct job *jp;
+	int i;
+	int status;
+
+	nextopt("");
+	jp = getjob(*argptr, 0);
+	if (jp->jobctl == 0)
+		error("job not created under job control");
+	out1fmt("%s", jp->ps[0].cmd);
+	for (i = 1; i < jp->nprocs; i++)
+		out1fmt(" | %s", jp->ps[i].cmd );
+	out1c('\n');
+	flushall();
+
+	for (i = 0; i < jp->nprocs; i++)
+	    if (tcsetpgrp(ttyfd, jp->ps[i].pid) != -1)
+		    break;
+
+	if (i >= jp->nprocs) {
+		error("Cannot set tty process group (%s) at %d",
+		    strerror(errno), __LINE__);
+	}
+	restartjob(jp);
+	INTOFF;
+	status = waitforjob(jp);
+	INTON;
+	return status;
+}
+
+static void
+set_curjob(struct job *jp, int mode)
+{
+	struct job *jp1, *jp2;
+	int i, ji;
+
+	ji = jp - jobtab;
+
+	/* first remove from list */
+	if (ji == curjob)
+		curjob = jp->prev_job;
+	else {
+		for (i = 0; i < njobs; i++) {
+			if (jobtab[i].prev_job != ji)
+				continue;
+			jobtab[i].prev_job = jp->prev_job;
+			break;
+		}
+	}
+
+	/* Then re-insert in correct position */
+	switch (mode) {
+	case 0:	/* job being deleted */
+		jp->prev_job = -1;
+		break;
+	case 1:	/* newly created job or backgrounded job,
+		   put after all stopped jobs. */
+		if (curjob != -1 && jobtab[curjob].state == JOBSTOPPED) {
+			for (jp1 = jobtab + curjob; ; jp1 = jp2) {
+				if (jp1->prev_job == -1)
+					break;
+				jp2 = jobtab + jp1->prev_job;
+				if (jp2->state != JOBSTOPPED)
+					break;
+			}
+			jp->prev_job = jp1->prev_job;
+			jp1->prev_job = ji;
+			break;
+		}
+		/* FALLTHROUGH */
+	case 2:	/* newly stopped job - becomes curjob */
+		jp->prev_job = curjob;
+		curjob = ji;
+		break;
+	}
+}
+
+int
+bgcmd(int argc, char **argv)
+{
+	struct job *jp;
+	int i;
+
+	nextopt("");
+	do {
+		jp = getjob(*argptr, 0);
+		if (jp->jobctl == 0)
+			error("job not created under job control");
+		set_curjob(jp, 1);
+		out1fmt("[%ld] %s", (long)(jp - jobtab + 1), jp->ps[0].cmd);
+		for (i = 1; i < jp->nprocs; i++)
+			out1fmt(" | %s", jp->ps[i].cmd );
+		out1c('\n');
+		flushall();
+		restartjob(jp);
+	} while (*argptr && *++argptr);
+	return 0;
+}
+
+
+STATIC void
+restartjob(struct job *jp)
+{
+	struct procstat *ps;
+	int i;
+
+	if (jp->state == JOBDONE)
+		return;
+	INTOFF;
+	for (i = 0; i < jp->nprocs; i++)
+		if (killpg(jp->ps[i].pid, SIGCONT) != -1)
+			break;
+	if (i >= jp->nprocs)
+		error("Cannot continue job (%s)", strerror(errno));
+	for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
+		if (WIFSTOPPED(ps->status)) {
+			ps->status = -1;
+			jp->state = JOBRUNNING;
+		}
+	}
+	INTON;
+}
+#endif
+
+static void
+showjob(struct output *out, struct job *jp, int mode)
+{
+	int procno;
+	int st;
+	struct procstat *ps;
+	int col;
+	char s[64];
+
+#if JOBS
+	if (mode & SHOW_PGID) {
+		/* just output process (group) id of pipeline */
+		outfmt(out, "%ld\n", (long)jp->ps->pid);
+		return;
+	}
+#endif
+
+	procno = jp->nprocs;
+	if (!procno)
+		return;
+
+	if (mode & SHOW_PID)
+		mode |= SHOW_MULTILINE;
+
+	if ((procno > 1 && !(mode & SHOW_MULTILINE))
+	    || (mode & SHOW_SIGNALLED)) {
+		/* See if we have more than one status to report */
+		ps = jp->ps;
+		st = ps->status;
+		do {
+			int st1 = ps->status;
+			if (st1 != st)
+				/* yes - need multi-line output */
+				mode |= SHOW_MULTILINE;
+			if (st1 == -1 || !(mode & SHOW_SIGNALLED) || WIFEXITED(st1))
+				continue;
+			if (WIFSTOPPED(st1) || ((st1 = WTERMSIG(st1) & 0x7f)
+			    && st1 != SIGINT && st1 != SIGPIPE))
+				mode |= SHOW_ISSIG;
+
+		} while (ps++, --procno);
+		procno = jp->nprocs;
+	}
+
+	if (mode & SHOW_SIGNALLED && !(mode & SHOW_ISSIG)) {
+		if (jp->state == JOBDONE && !(mode & SHOW_NO_FREE)) {
+			TRACE(("showjob: freeing job %d\n", jp - jobtab + 1));
+			freejob(jp);
+		}
+		return;
+	}
+
+	for (ps = jp->ps; --procno >= 0; ps++) {	/* for each process */
+		if (ps == jp->ps)
+			fmtstr(s, 16, "[%ld] %c ",
+				(long)(jp - jobtab + 1),
+#if JOBS
+				jp == jobtab + curjob ? '+' :
+				curjob != -1 && jp == jobtab +
+					    jobtab[curjob].prev_job ? '-' :
+#endif
+				' ');
+		else
+			fmtstr(s, 16, "      " );
+		col = strlen(s);
+		if (mode & SHOW_PID) {
+			fmtstr(s + col, 16, "%ld ", (long)ps->pid);
+			     col += strlen(s + col);
+		}
+		if (ps->status == -1) {
+			scopy("Running", s + col);
+		} else if (WIFEXITED(ps->status)) {
+			st = WEXITSTATUS(ps->status);
+			if (st)
+				fmtstr(s + col, 16, "Done(%d)", st);
+			else
+				fmtstr(s + col, 16, "Done");
+		} else {
+#if JOBS
+			if (WIFSTOPPED(ps->status)) 
+				st = WSTOPSIG(ps->status);
+			else /* WIFSIGNALED(ps->status) */
+#endif
+				st = WTERMSIG(ps->status);
+			st &= 0x7f;
+			if (st < NSIG && sys_siglist[st])
+				scopyn(sys_siglist[st], s + col, 32);
+			else
+				fmtstr(s + col, 16, "Signal %d", st);
+			if (WCOREDUMP(ps->status)) {
+				col += strlen(s + col);
+				scopyn(" (core dumped)", s + col,  64 - col);
+			}
+		}
+		col += strlen(s + col);
+		outstr(s, out);
+		do {
+			outc(' ', out);
+			col++;
+		} while (col < 30);
+		outstr(ps->cmd, out);
+		if (mode & SHOW_MULTILINE) {
+			if (procno > 0) {
+				outc(' ', out);
+				outc('|', out);
+			}
+		} else {
+			while (--procno >= 0)
+				outfmt(out, " | %s", (++ps)->cmd );
+		}
+		outc('\n', out);
+	}
+	flushout(out);
+	jp->changed = 0;
+	if (jp->state == JOBDONE && !(mode & SHOW_NO_FREE))
+		freejob(jp);
+}
+
+
+int
+jobscmd(int argc, char **argv)
+{
+	int mode, m;
+	int sv = jobs_invalid;
+
+	jobs_invalid = 0;
+	mode = 0;
+	while ((m = nextopt("lp")))
+		if (m == 'l')
+			mode = SHOW_PID;
+		else
+			mode = SHOW_PGID;
+	if (*argptr)
+		do
+			showjob(out1, getjob(*argptr,0), mode);
+		while (*++argptr);
+	else
+		showjobs(out1, mode);
+	jobs_invalid = sv;
+	return 0;
+}
+
+
+/*
+ * Print a list of jobs.  If "change" is nonzero, only print jobs whose
+ * statuses have changed since the last call to showjobs.
+ *
+ * If the shell is interrupted in the process of creating a job, the
+ * result may be a job structure containing zero processes.  Such structures
+ * will be freed here.
+ */
+
+void
+showjobs(struct output *out, int mode)
+{
+	int jobno;
+	struct job *jp;
+	int silent = 0, gotpid;
+
+	TRACE(("showjobs(%x) called\n", mode));
+
+	/* If not even one one job changed, there is nothing to do */
+	gotpid = dowait(0, NULL);
+	while (dowait(0, NULL) > 0)
+		continue;
+#ifdef JOBS
+	/*
+	 * Check if we are not in our foreground group, and if not
+	 * put us in it.
+	 */
+	if (mflag && gotpid != -1 && tcgetpgrp(ttyfd) != getpid()) {
+		if (tcsetpgrp(ttyfd, getpid()) == -1)
+			error("Cannot set tty process group (%s) at %d",
+			    strerror(errno), __LINE__);
+		TRACE(("repaired tty process group\n"));
+		silent = 1;
+	}
+#endif
+	if (jobs_invalid)
+		return;
+
+	for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
+		if (!jp->used)
+			continue;
+		if (jp->nprocs == 0) {
+			freejob(jp);
+			continue;
+		}
+		if ((mode & SHOW_CHANGED) && !jp->changed)
+			continue;
+		if (silent && jp->changed) {
+			jp->changed = 0;
+			continue;
+		}
+		showjob(out, jp, mode);
+	}
+}
+
+/*
+ * Mark a job structure as unused.
+ */
+
+STATIC void
+freejob(struct job *jp)
+{
+	INTOFF;
+	if (jp->ps != &jp->ps0) {
+		ckfree(jp->ps);
+		jp->ps = &jp->ps0;
+	}
+	jp->nprocs = 0;
+	jp->used = 0;
+#if JOBS
+	set_curjob(jp, 0);
+#endif
+	INTON;
+}
+
+
+
+int
+waitcmd(int argc, char **argv)
+{
+	struct job *job;
+	int status, retval = 127;
+	struct job *jp;
+
+	nextopt("");
+
+	if (!*argptr) {
+		/* wait for all jobs */
+		jp = jobtab;
+		if (jobs_invalid)
+			return 0;
+		for (;;) {
+			if (jp >= jobtab + njobs) {
+				/* no running procs */
+				return 0;
+			}
+			if (!jp->used || jp->state != JOBRUNNING) {
+				jp++;
+				continue;
+			}
+			if (dowait(1, (struct job *)NULL) == -1)
+			       return 128 + SIGINT;
+			jp = jobtab;
+		}
+	}
+
+	for (; *argptr; argptr++) {
+		job = getjob(*argptr, 1);
+		if (!job) {
+			retval = 127;
+			continue;
+		}
+		/* loop until process terminated or stopped */
+		while (job->state == JOBRUNNING) {
+			if (dowait(1, (struct job *)NULL) == -1)
+			       return 128 + SIGINT;
+		}
+		status = job->ps[job->nprocs].status;
+		if (WIFEXITED(status))
+			retval = WEXITSTATUS(status);
+#if JOBS
+		else if (WIFSTOPPED(status))
+			retval = WSTOPSIG(status) + 128;
+#endif
+		else {
+			/* XXX: limits number of signals */
+			retval = WTERMSIG(status) + 128;
+		}
+		if (!iflag)
+			freejob(job);
+	}
+	return retval;
+}
+
+
+
+int
+jobidcmd(int argc, char **argv)
+{
+	struct job *jp;
+	int i;
+
+	nextopt("");
+	jp = getjob(*argptr, 0);
+	for (i = 0 ; i < jp->nprocs ; ) {
+		out1fmt("%ld", (long)jp->ps[i].pid);
+		out1c(++i < jp->nprocs ? ' ' : '\n');
+	}
+	return 0;
+}
+
+int
+getjobpgrp(const char *name)
+{
+	struct job *jp;
+
+	jp = getjob(name, 1);
+	if (jp == 0)
+		return 0;
+	return -jp->ps[0].pid;
+}
+
+/*
+ * Convert a job name to a job structure.
+ */
+
+STATIC struct job *
+getjob(const char *name, int noerror)
+{
+	int jobno = -1;
+	struct job *jp;
+	int pid;
+	int i;
+	const char *err_msg = "No such job: %s";
+		
+	if (name == NULL) {
+#if JOBS
+		jobno = curjob;
+#endif
+		err_msg = "No current job";
+	} else if (name[0] == '%') {
+		if (is_number(name + 1)) {
+			jobno = number(name + 1) - 1;
+		} else if (!name[2]) {
+			switch (name[1]) {
+#if JOBS
+			case 0:
+			case '+':
+			case '%':
+				jobno = curjob;
+				err_msg = "No current job";
+				break;
+			case '-':
+				jobno = curjob;
+				if (jobno != -1)
+					jobno = jobtab[jobno].prev_job;
+				err_msg = "No previous job";
+				break;
+#endif
+			default:
+				goto check_pattern;
+			}
+		} else {
+			struct job *found;
+    check_pattern:
+			found = NULL;
+			for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
+				if (!jp->used || jp->nprocs <= 0)
+					continue;
+				if ((name[1] == '?'
+					&& strstr(jp->ps[0].cmd, name + 2))
+				    || prefix(name + 1, jp->ps[0].cmd)) {
+					if (found) {
+						err_msg = "%s: ambiguous";
+						found = 0;
+						break;
+					}
+					found = jp;
+				}
+			}
+			if (found)
+				return found;
+		}
+
+	} else if (is_number(name)) {
+		pid = number(name);
+		for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
+			if (jp->used && jp->nprocs > 0
+			 && jp->ps[jp->nprocs - 1].pid == pid)
+				return jp;
+		}
+	}
+
+	if (!jobs_invalid && jobno >= 0 && jobno < njobs) {
+		jp = jobtab + jobno;
+		if (jp->used)
+			return jp;
+	}
+	if (!noerror)
+		error(err_msg, name);
+	return 0;
+}
+
+
+
+/*
+ * Return a new job structure,
+ */
+
+struct job *
+makejob(union node *node, int nprocs)
+{
+	int i;
+	struct job *jp;
+
+	if (jobs_invalid) {
+		for (i = njobs, jp = jobtab ; --i >= 0 ; jp++) {
+			if (jp->used)
+				freejob(jp);
+		}
+		jobs_invalid = 0;
+	}
+
+	for (i = njobs, jp = jobtab ; ; jp++) {
+		if (--i < 0) {
+			INTOFF;
+			if (njobs == 0) {
+				jobtab = ckmalloc(4 * sizeof jobtab[0]);
+			} else {
+				jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
+				memcpy(jp, jobtab, njobs * sizeof jp[0]);
+				/* Relocate `ps' pointers */
+				for (i = 0; i < njobs; i++)
+					if (jp[i].ps == &jobtab[i].ps0)
+						jp[i].ps = &jp[i].ps0;
+				ckfree(jobtab);
+				jobtab = jp;
+			}
+			jp = jobtab + njobs;
+			for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0);
+			INTON;
+			break;
+		}
+		if (jp->used == 0)
+			break;
+	}
+	INTOFF;
+	jp->state = JOBRUNNING;
+	jp->used = 1;
+	jp->changed = 0;
+	jp->nprocs = 0;
+#if JOBS
+	jp->jobctl = jobctl;
+	set_curjob(jp, 1);
+#endif
+	if (nprocs > 1) {
+		jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
+	} else {
+		jp->ps = &jp->ps0;
+	}
+	INTON;
+	TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs,
+	    jp - jobtab + 1));
+	return jp;
+}
+
+
+/*
+ * Fork off a subshell.  If we are doing job control, give the subshell its
+ * own process group.  Jp is a job structure that the job is to be added to.
+ * N is the command that will be evaluated by the child.  Both jp and n may
+ * be NULL.  The mode parameter can be one of the following:
+ *	FORK_FG - Fork off a foreground process.
+ *	FORK_BG - Fork off a background process.
+ *	FORK_NOJOB - Like FORK_FG, but don't give the process its own
+ *		     process group even if job control is on.
+ *
+ * When job control is turned off, background processes have their standard
+ * input redirected to /dev/null (except for the second and later processes
+ * in a pipeline).
+ */
+
+int
+forkshell(struct job *jp, union node *n, int mode)
+{
+	int pid;
+
+	TRACE(("forkshell(%%%d, %p, %d) called\n", jp - jobtab, n, mode));
+	switch ((pid = fork())) {
+	case -1:
+		TRACE(("Fork failed, errno=%d\n", errno));
+		INTON;
+		error("Cannot fork");
+		break;
+	case 0:
+		forkchild(jp, n, mode, 0);
+		return 0;
+	default:
+		return forkparent(jp, n, mode, pid);
+	}
+}
+
+int
+forkparent(struct job *jp, union node *n, int mode, pid_t pid)
+{
+	int pgrp;
+
+	if (rootshell && mode != FORK_NOJOB && mflag) {
+		if (jp == NULL || jp->nprocs == 0)
+			pgrp = pid;
+		else
+			pgrp = jp->ps[0].pid;
+#ifdef USE_PROCESS_GROUPS
+		/* This can fail because we are doing it in the child also */
+		(void)setpgid(pid, pgrp);
+#endif
+	}
+	if (mode == FORK_BG)
+		backgndpid = pid;		/* set $! */
+	if (jp) {
+		struct procstat *ps = &jp->ps[jp->nprocs++];
+		ps->pid = pid;
+		ps->status = -1;
+		ps->cmd[0] = 0;
+		if (/* iflag && rootshell && */ n)
+			commandtext(ps, n);
+	}
+	TRACE(("In parent shell:  child = %d\n", pid));
+	return pid;
+}
+
+void
+forkchild(struct job *jp, union node *n, int mode, int vforked)
+{
+	int wasroot;
+	int pgrp;
+	const char *devnull = _PATH_DEVNULL;
+	const char *nullerr = "Can't open %s";
+
+	wasroot = rootshell;
+	TRACE(("Child shell %d\n", getpid()));
+	if (!vforked)
+		rootshell = 0;
+
+	closescript(vforked);
+	clear_traps(vforked);
+#if JOBS
+	if (!vforked)
+		jobctl = 0;		/* do job control only in root shell */
+	if (wasroot && mode != FORK_NOJOB && mflag) {
+		if (jp == NULL || jp->nprocs == 0)
+			pgrp = getpid();
+		else
+			pgrp = jp->ps[0].pid;
+#ifdef USE_PROCESS_GROUPS
+		/* This can fail because we are doing it in the parent also */
+		(void)setpgid(0, pgrp);
+		if (mode == FORK_FG) {
+			if (tcsetpgrp(ttyfd, pgrp) == -1)
+				error("Cannot set tty process group (%s) at %d",
+				    strerror(errno), __LINE__);
+		}
+#endif
+		setsignal(SIGTSTP, vforked);
+		setsignal(SIGTTOU, vforked);
+	} else if (mode == FORK_BG) {
+		ignoresig(SIGINT, vforked);
+		ignoresig(SIGQUIT, vforked);
+		if ((jp == NULL || jp->nprocs == 0) &&
+		    ! fd0_redirected_p ()) {
+			close(0);
+			if (open(devnull, O_RDONLY) != 0)
+				error(nullerr, devnull);
+		}
+	}
+#else
+	if (mode == FORK_BG) {
+		ignoresig(SIGINT, vforked);
+		ignoresig(SIGQUIT, vforked);
+		if ((jp == NULL || jp->nprocs == 0) &&
+		    ! fd0_redirected_p ()) {
+			close(0);
+			if (open(devnull, O_RDONLY) != 0)
+				error(nullerr, devnull);
+		}
+	}
+#endif
+	if (wasroot && iflag) {
+		setsignal(SIGINT, vforked);
+		setsignal(SIGQUIT, vforked);
+		setsignal(SIGTERM, vforked);
+	}
+
+	if (!vforked)
+		jobs_invalid = 1;
+}
+
+/*
+ * Wait for job to finish.
+ *
+ * Under job control we have the problem that while a child process is
+ * running interrupts generated by the user are sent to the child but not
+ * to the shell.  This means that an infinite loop started by an inter-
+ * active user may be hard to kill.  With job control turned off, an
+ * interactive user may place an interactive program inside a loop.  If
+ * the interactive program catches interrupts, the user doesn't want
+ * these interrupts to also abort the loop.  The approach we take here
+ * is to have the shell ignore interrupt signals while waiting for a
+ * forground process to terminate, and then send itself an interrupt
+ * signal if the child process was terminated by an interrupt signal.
+ * Unfortunately, some programs want to do a bit of cleanup and then
+ * exit on interrupt; unless these processes terminate themselves by
+ * sending a signal to themselves (instead of calling exit) they will
+ * confuse this approach.
+ */
+
+int
+waitforjob(struct job *jp)
+{
+#if JOBS
+	int mypgrp = getpgrp();
+#endif
+	int status;
+	int st;
+
+	INTOFF;
+	TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1));
+	while (jp->state == JOBRUNNING) {
+		dowait(1, jp);
+	}
+#if JOBS
+	if (jp->jobctl) {
+		if (tcsetpgrp(ttyfd, mypgrp) == -1)
+			error("Cannot set tty process group (%s) at %d",
+			    strerror(errno), __LINE__);
+	}
+	if (jp->state == JOBSTOPPED && curjob != jp - jobtab)
+		set_curjob(jp, 2);
+#endif
+	status = jp->ps[jp->nprocs - 1].status;
+	/* convert to 8 bits */
+	if (WIFEXITED(status))
+		st = WEXITSTATUS(status);
+#if JOBS
+	else if (WIFSTOPPED(status))
+		st = WSTOPSIG(status) + 128;
+#endif
+	else
+		st = WTERMSIG(status) + 128;
+	TRACE(("waitforjob: job %d, nproc %d, status %x, st %x\n",
+		jp - jobtab + 1, jp->nprocs, status, st ));
+#if JOBS
+	if (jp->jobctl) {
+		/*
+		 * This is truly gross.
+		 * If we're doing job control, then we did a TIOCSPGRP which
+		 * caused us (the shell) to no longer be in the controlling
+		 * session -- so we wouldn't have seen any ^C/SIGINT.  So, we
+		 * intuit from the subprocess exit status whether a SIGINT
+		 * occurred, and if so interrupt ourselves.  Yuck.  - mycroft
+		 */
+		if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
+			raise(SIGINT);
+	}
+#endif
+	if (! JOBS || jp->state == JOBDONE)
+		freejob(jp);
+	INTON;
+	return st;
+}
+
+
+
+/*
+ * Wait for a process to terminate.
+ */
+
+STATIC int
+dowait(int block, struct job *job)
+{
+	int pid;
+	int status;
+	struct procstat *sp;
+	struct job *jp;
+	struct job *thisjob;
+	int done;
+	int stopped;
+	extern volatile char gotsig[];
+
+	TRACE(("dowait(%d) called\n", block));
+	do {
+		pid = waitproc(block, job, &status);
+		TRACE(("wait returns pid %d, status %d\n", pid, status));
+	} while (pid == -1 && errno == EINTR && gotsig[SIGINT - 1] == 0);
+	if (pid <= 0)
+		return pid;
+	INTOFF;
+	thisjob = NULL;
+	for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
+		if (jp->used) {
+			done = 1;
+			stopped = 1;
+			for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
+				if (sp->pid == -1)
+					continue;
+				if (sp->pid == pid) {
+					TRACE(("Job %d: changing status of proc %d from 0x%x to 0x%x\n", jp - jobtab + 1, pid, sp->status, status));
+					sp->status = status;
+					thisjob = jp;
+				}
+				if (sp->status == -1)
+					stopped = 0;
+				else if (WIFSTOPPED(sp->status))
+					done = 0;
+			}
+			if (stopped) {		/* stopped or done */
+				int state = done ? JOBDONE : JOBSTOPPED;
+				if (jp->state != state) {
+					TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
+					jp->state = state;
+#if JOBS
+					if (done)
+						set_curjob(jp, 0);
+#endif
+				}
+			}
+		}
+	}
+
+	if (thisjob && thisjob->state != JOBRUNNING) {
+		int mode = 0;
+		if (!rootshell || !iflag)
+			mode = SHOW_SIGNALLED;
+		if (job == thisjob)
+			mode = SHOW_SIGNALLED | SHOW_NO_FREE;
+		if (mode)
+			showjob(out2, thisjob, mode);
+		else {
+			TRACE(("Not printing status, rootshell=%d, job=%p\n",
+				rootshell, job));
+			thisjob->changed = 1;
+		}
+	}
+
+	INTON;
+	return pid;
+}
+
+
+
+/*
+ * Do a wait system call.  If job control is compiled in, we accept
+ * stopped processes.  If block is zero, we return a value of zero
+ * rather than blocking.
+ *
+ * System V doesn't have a non-blocking wait system call.  It does
+ * have a SIGCLD signal that is sent to a process when one of it's
+ * children dies.  The obvious way to use SIGCLD would be to install
+ * a handler for SIGCLD which simply bumped a counter when a SIGCLD
+ * was received, and have waitproc bump another counter when it got
+ * the status of a process.  Waitproc would then know that a wait
+ * system call would not block if the two counters were different.
+ * This approach doesn't work because if a process has children that
+ * have not been waited for, System V will send it a SIGCLD when it
+ * installs a signal handler for SIGCLD.  What this means is that when
+ * a child exits, the shell will be sent SIGCLD signals continuously
+ * until is runs out of stack space, unless it does a wait call before
+ * restoring the signal handler.  The code below takes advantage of
+ * this (mis)feature by installing a signal handler for SIGCLD and
+ * then checking to see whether it was called.  If there are any
+ * children to be waited for, it will be.
+ *
+ * If neither SYSV nor BSD is defined, we don't implement nonblocking
+ * waits at all.  In this case, the user will not be informed when
+ * a background process until the next time she runs a real program
+ * (as opposed to running a builtin command or just typing return),
+ * and the jobs command may give out of date information.
+ */
+
+#ifdef SYSV
+STATIC int gotsigchild;
+
+STATIC int onsigchild() {
+	gotsigchild = 1;
+}
+#endif
+
+
+STATIC int
+waitproc(int block, struct job *jp, int *status)
+{
+#ifdef BSD
+	int flags = 0;
+
+#if JOBS
+	if (jp != NULL && jp->jobctl)
+		flags |= WUNTRACED;
+#endif
+	if (block == 0)
+		flags |= WNOHANG;
+	return wait3(status, flags, (struct rusage *)NULL);
+#else
+#ifdef SYSV
+	int (*save)();
+
+	if (block == 0) {
+		gotsigchild = 0;
+		save = signal(SIGCLD, onsigchild);
+		signal(SIGCLD, save);
+		if (gotsigchild == 0)
+			return 0;
+	}
+	return wait(status);
+#else
+	if (block == 0)
+		return 0;
+	return wait(status);
+#endif
+#endif
+}
+
+/*
+ * return 1 if there are stopped jobs, otherwise 0
+ */
+int job_warning = 0;
+int
+stoppedjobs(void)
+{
+	int jobno;
+	struct job *jp;
+
+	if (job_warning || jobs_invalid)
+		return (0);
+	for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
+		if (jp->used == 0)
+			continue;
+		if (jp->state == JOBSTOPPED) {
+			out2str("You have stopped jobs.\n");
+			job_warning = 2;
+			return (1);
+		}
+	}
+
+	return (0);
+}
+
+/*
+ * Return a string identifying a command (to be printed by the
+ * jobs command).
+ */
+
+STATIC char *cmdnextc;
+STATIC int cmdnleft;
+
+void
+commandtext(struct procstat *ps, union node *n)
+{
+	int len;
+
+	cmdnextc = ps->cmd;
+	if (iflag || mflag || sizeof ps->cmd < 100)
+		len = sizeof(ps->cmd);
+	else
+		len = sizeof(ps->cmd) / 10;
+	cmdnleft = len;
+	cmdtxt(n);
+	if (cmdnleft <= 0) {
+		char *p = ps->cmd + len - 4;
+		p[0] = '.';
+		p[1] = '.';
+		p[2] = '.';
+		p[3] = 0;
+	} else
+		*cmdnextc = '\0';
+	TRACE(("commandtext: ps->cmd %x, end %x, left %d\n\t\"%s\"\n",
+		ps->cmd, cmdnextc, cmdnleft, ps->cmd));
+}
+
+
+STATIC void
+cmdtxt(union node *n)
+{
+	union node *np;
+	struct nodelist *lp;
+	const char *p;
+	int i;
+	char s[2];
+
+	if (n == NULL || cmdnleft <= 0)
+		return;
+	switch (n->type) {
+	case NSEMI:
+		cmdtxt(n->nbinary.ch1);
+		cmdputs("; ");
+		cmdtxt(n->nbinary.ch2);
+		break;
+	case NAND:
+		cmdtxt(n->nbinary.ch1);
+		cmdputs(" && ");
+		cmdtxt(n->nbinary.ch2);
+		break;
+	case NOR:
+		cmdtxt(n->nbinary.ch1);
+		cmdputs(" || ");
+		cmdtxt(n->nbinary.ch2);
+		break;
+	case NPIPE:
+		for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
+			cmdtxt(lp->n);
+			if (lp->next)
+				cmdputs(" | ");
+		}
+		break;
+	case NSUBSHELL:
+		cmdputs("(");
+		cmdtxt(n->nredir.n);
+		cmdputs(")");
+		break;
+	case NREDIR:
+	case NBACKGND:
+		cmdtxt(n->nredir.n);
+		break;
+	case NIF:
+		cmdputs("if ");
+		cmdtxt(n->nif.test);
+		cmdputs("; then ");
+		cmdtxt(n->nif.ifpart);
+		if (n->nif.elsepart) {
+			cmdputs("; else ");
+			cmdtxt(n->nif.elsepart);
+		}
+		cmdputs("; fi");
+		break;
+	case NWHILE:
+		cmdputs("while ");
+		goto until;
+	case NUNTIL:
+		cmdputs("until ");
+until:
+		cmdtxt(n->nbinary.ch1);
+		cmdputs("; do ");
+		cmdtxt(n->nbinary.ch2);
+		cmdputs("; done");
+		break;
+	case NFOR:
+		cmdputs("for ");
+		cmdputs(n->nfor.var);
+		cmdputs(" in ");
+		cmdlist(n->nfor.args, 1);
+		cmdputs("; do ");
+		cmdtxt(n->nfor.body);
+		cmdputs("; done");
+		break;
+	case NCASE:
+		cmdputs("case ");
+		cmdputs(n->ncase.expr->narg.text);
+		cmdputs(" in ");
+		for (np = n->ncase.cases; np; np = np->nclist.next) {
+			cmdtxt(np->nclist.pattern);
+			cmdputs(") ");
+			cmdtxt(np->nclist.body);
+			cmdputs(";; ");
+		}
+		cmdputs("esac");
+		break;
+	case NDEFUN:
+		cmdputs(n->narg.text);
+		cmdputs("() { ... }");
+		break;
+	case NCMD:
+		cmdlist(n->ncmd.args, 1);
+		cmdlist(n->ncmd.redirect, 0);
+		break;
+	case NARG:
+		cmdputs(n->narg.text);
+		break;
+	case NTO:
+		p = ">";  i = 1;  goto redir;
+	case NCLOBBER:
+		p = ">|";  i = 1;  goto redir;
+	case NAPPEND:
+		p = ">>";  i = 1;  goto redir;
+	case NTOFD:
+		p = ">&";  i = 1;  goto redir;
+	case NFROM:
+		p = "<";  i = 0;  goto redir;
+	case NFROMFD:
+		p = "<&";  i = 0;  goto redir;
+	case NFROMTO:
+		p = "<>";  i = 0;  goto redir;
+redir:
+		if (n->nfile.fd != i) {
+			s[0] = n->nfile.fd + '0';
+			s[1] = '\0';
+			cmdputs(s);
+		}
+		cmdputs(p);
+		if (n->type == NTOFD || n->type == NFROMFD) {
+			s[0] = n->ndup.dupfd + '0';
+			s[1] = '\0';
+			cmdputs(s);
+		} else {
+			cmdtxt(n->nfile.fname);
+		}
+		break;
+	case NHERE:
+	case NXHERE:
+		cmdputs("<<...");
+		break;
+	default:
+		cmdputs("???");
+		break;
+	}
+}
+
+STATIC void
+cmdlist(union node *np, int sep)
+{
+	for (; np; np = np->narg.next) {
+		if (!sep)
+			cmdputs(" ");
+		cmdtxt(np);
+		if (sep && np->narg.next)
+			cmdputs(" ");
+	}
+}
+
+
+STATIC void
+cmdputs(const char *s)
+{
+	const char *p, *str = 0;
+	char c, cc[2] = " ";
+	char *nextc;
+	int nleft;
+	int subtype = 0;
+	int quoted = 0;
+	static char vstype[16][4] = { "", "}", "-", "+", "?", "=",
+					"#", "##", "%", "%%" };
+
+	p = s;
+	nextc = cmdnextc;
+	nleft = cmdnleft;
+	while (nleft > 0 && (c = *p++) != 0) {
+		switch (c) {
+		case CTLESC:
+			c = *p++;
+			break;
+		case CTLVAR:
+			subtype = *p++;
+			if ((subtype & VSTYPE) == VSLENGTH)
+				str = "${#";
+			else
+				str = "${";
+			if (!(subtype & VSQUOTE) != !(quoted & 1)) {
+				quoted ^= 1;
+				c = '"';
+			} else
+				c = *str++;
+			break;
+		case CTLENDVAR:
+			if (quoted & 1) {
+				c = '"';
+				str = "}";
+			} else
+				c = '}';
+			quoted >>= 1;
+			subtype = 0;
+			break;
+		case CTLBACKQ:
+			c = '$';
+			str = "(...)";
+			break;
+		case CTLBACKQ+CTLQUOTE:
+			c = '"';
+			str = "$(...)\"";
+			break;
+		case CTLARI:
+			c = '$';
+			str = "((";
+			break;
+		case CTLENDARI:
+			c = ')';
+			str = ")";
+			break;
+		case CTLQUOTEMARK:
+			quoted ^= 1;
+			c = '"';
+			break;
+		case '=':
+			if (subtype == 0)
+				break;
+			str = vstype[subtype & VSTYPE];
+			if (subtype & VSNUL)
+				c = ':';
+			else
+				c = *str++;
+			if (c != '}')
+				quoted <<= 1;
+			break;
+		case '\'':
+		case '\\':
+		case '"':
+		case '$':
+			/* These can only happen inside quotes */
+			cc[0] = c;
+			str = cc;
+			c = '\\';
+			break;
+		default:
+			break;
+		}
+		do {
+			*nextc++ = c;
+		} while (--nleft > 0 && str && (c = *str++));
+		str = 0;
+	}
+	if ((quoted & 1) && nleft) {
+		*nextc++ = '"';
+		nleft--;
+	}
+	cmdnleft = nleft;
+	cmdnextc = nextc;
+}