jobs.c

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}


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);