jobs.c

一个开放源代码的 AT&T 的 Korn Shell 的复制品, 支持大多数 ksh89 的特性。

			}
		}
		remove_job(j, "child");	/* in case of `jobs` command */
		nzombie = 0;
#ifdef JOBS
		ttypgrp_ok = 0;
		Flag(FMONITOR) = 0;
#endif /* JOBS */
		Flag(FTALKING) = 0;
#ifdef OS2
		if (tty_fd >= 0)
			flags |= XINTACT;
#endif /* OS2 */
		tty_close();
		cleartraps();
		execute(t, (flags & XERROK) | XEXEC); /* no return */
		internal_errorf(0, "exchild: execute() returned");
		unwind(LLEAVE);
		/* NOTREACHED */
	}

	/* shell (parent) stuff */
	/* Ensure next child gets a (slightly) different $RANDOM sequence */
	change_random();
	if (!(flags & XPIPEO)) {	/* last process in a job */
#ifdef TTY_PGRP
		/* YYY: Is this needed? (see also YYY above)
		   if (Flag(FMONITOR) && !(flags&(XXCOM|XBGND)))
			tcsetpgrp(tty_fd, j->pgrp);
		*/
#endif /* TTY_PGRP */
		j_startjob(j);
#ifdef KSH
		if (flags & XCOPROC) {
			j->coproc_id = coproc.id;
			coproc.njobs++; /* n jobs using co-process output */
			coproc.job = (void *) j; /* j using co-process input */
		}
#endif /* KSH */
		if (flags & XBGND) {
			j_set_async(j);
			if (Flag(FTALKING)) {
				shf_fprintf(shl_out, "[%d]", j->job);
				for (p = j->proc_list; p; p = p->next)
					shf_fprintf(shl_out, " %d", p->pid);
				shf_putchar('\n', shl_out);
				shf_flush(shl_out);
			}
		} else
			rv = j_waitj(j, JW_NONE, "jw:last proc");
	}

#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */

	return rv;
}

/* start the last job: only used for `command` jobs */
void
startlast()
{
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */

	if (last_job) { /* no need to report error - waitlast() will do it */
		/* ensure it isn't removed by check_job() */
		last_job->flags |= JF_WAITING;
		j_startjob(last_job);
	}
#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
}

/* wait for last job: only used for `command` jobs */
int
waitlast()
{
	int	rv;
	Job	*j;
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */

	j = last_job;
	if (!j || !(j->flags & JF_STARTED)) {
		if (!j)
			warningf(TRUE, "waitlast: no last job");
		else
			internal_errorf(0, "waitlast: not started");
#ifdef JOB_SIGS
		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
		return 125; /* not so arbitrary, non-zero value */
	}

	rv = j_waitj(j, JW_NONE, "jw:waitlast");

#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */

	return rv;
}

/* wait for child, interruptable. */
int
waitfor(cp, sigp)
	const char *cp;
	int	*sigp;
{
	int	rv;
	Job	*j;
	int	ecode;
	int	flags = JW_INTERRUPT|JW_ASYNCNOTIFY;
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */

	*sigp = 0;

	if (cp == (char *) 0) {
		/* wait for an unspecified job - always returns 0, so
		 * don't have to worry about exited/signaled jobs
		 */
		for (j = job_list; j; j = j->next)
			/* at&t ksh will wait for stopped jobs - we don't */
			if (j->ppid == procpid && j->state == PRUNNING)
				break;
		if (!j) {
#ifdef JOB_SIGS
			sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
			return -1;
		}
	} else if ((j = j_lookup(cp, &ecode))) {
		/* don't report normal job completion */
		flags &= ~JW_ASYNCNOTIFY;
		if (j->ppid != procpid) {
#ifdef JOB_SIGS
			sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
			return -1;
		}
	} else {
#ifdef JOB_SIGS
		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
		if (ecode != JL_NOSUCH)
			bi_errorf("%s: %s", cp, lookup_msgs[ecode]);
		return -1;
	}

	/* at&t ksh will wait for stopped jobs - we don't */
	rv = j_waitj(j, flags, "jw:waitfor");

#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */

	if (rv < 0) /* we were interrupted */
		*sigp = 128 + -rv;

	return rv;
}

/* kill (built-in) a job */
int
j_kill(cp, sig)
	const char *cp;
	int	sig;
{
	Job	*j;
	Proc	*p;
	int	rv = 0;
	int	ecode;
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */

	if ((j = j_lookup(cp, &ecode)) == (Job *) 0) {
#ifdef JOB_SIGS
		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
		bi_errorf("%s: %s", cp, lookup_msgs[ecode]);
		return 1;
	}

	if (j->pgrp == 0) {	/* started when !Flag(FMONITOR) */
		for (p=j->proc_list; p != (Proc *) 0; p = p->next)
			if (kill(p->pid, sig) < 0) {
				bi_errorf("%s: %s", cp, strerror(errno));
				rv = 1;
			}
	} else {
#ifdef JOBS
		if (j->state == PSTOPPED && (sig == SIGTERM || sig == SIGHUP))
			(void) killpg(j->pgrp, SIGCONT);
#endif /* JOBS */
		if (killpg(j->pgrp, sig) < 0) {
			bi_errorf("%s: %s", cp, strerror(errno));
			rv = 1;
		}
	}

#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */

	return rv;
}

#ifdef JOBS
/* fg and bg built-ins: called only if Flag(FMONITOR) set */
int
j_resume(cp, bg)
	const char *cp;
	int	bg;
{
	Job	*j;
	Proc	*p;
	int	ecode;
	int	running;
	int	rv = 0;
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);

	if ((j = j_lookup(cp, &ecode)) == (Job *) 0) {
		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
		bi_errorf("%s: %s", cp, lookup_msgs[ecode]);
		return 1;
	}

	if (j->pgrp == 0) {
		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
		bi_errorf("job not job-controlled");
		return 1;
	}

	if (bg)
		shprintf("[%d] ", j->job);

	running = 0;
	for (p = j->proc_list; p != (Proc *) 0; p = p->next) {
		if (p->state == PSTOPPED) {
			p->state = PRUNNING;
			WSTATUS(p->status) = 0;
			running = 1;
		}
		shprintf("%s%s", p->command, p->next ? "| " : null);
	}
	shprintf(newline);
	shf_flush(shl_stdout);
	if (running)
		j->state = PRUNNING;

	put_job(j, PJ_PAST_STOPPED);
	if (bg)
		j_set_async(j);
	else {
# ifdef TTY_PGRP
		/* attach tty to job */
		if (j->state == PRUNNING) {
			if (ttypgrp_ok && (j->flags & JF_SAVEDTTY)) {
				set_tty(tty_fd, &j->ttystate, TF_NONE);
			}
			/* See comment in j_waitj regarding saved_ttypgrp. */
			if (ttypgrp_ok && tcsetpgrp(tty_fd, (j->flags & JF_SAVEDTTYPGRP) ? j->saved_ttypgrp : j->pgrp) < 0) {
				if (j->flags & JF_SAVEDTTY) {
					set_tty(tty_fd, &tty_state, TF_NONE);
				}
				sigprocmask(SIG_SETMASK, &omask,
					(sigset_t *) 0);
				bi_errorf("1st tcsetpgrp(%d, %d) failed: %s",
					tty_fd, (int) ((j->flags & JF_SAVEDTTYPGRP) ? j->saved_ttypgrp : j->pgrp), strerror(errno));
				return 1;
			}
		}
# endif /* TTY_PGRP */
		j->flags |= JF_FG;
		j->flags &= ~JF_KNOWN;
		if (j == async_job)
			async_job = (Job *) 0;
	}

	if (j->state == PRUNNING && killpg(j->pgrp, SIGCONT) < 0) {
		int	err = errno;

		if (!bg) {
			j->flags &= ~JF_FG;
# ifdef TTY_PGRP
			if (ttypgrp_ok && (j->flags & JF_SAVEDTTY)) {
				set_tty(tty_fd, &tty_state, TF_NONE);
			}
			if (ttypgrp_ok && tcsetpgrp(tty_fd, our_pgrp) < 0) {
				warningf(TRUE,
				"fg: 2nd tcsetpgrp(%d, %d) failed: %s",
					tty_fd, (int) our_pgrp,
					strerror(errno));
			}
# endif /* TTY_PGRP */
		}
		sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
		bi_errorf("cannot continue job %s: %s",
			cp, strerror(err));
		return 1;
	}
	if (!bg) {
# ifdef TTY_PGRP
		if (ttypgrp_ok) {
			j->flags &= ~(JF_SAVEDTTY | JF_SAVEDTTYPGRP);
		}
# endif /* TTY_PGRP */
		rv = j_waitj(j, JW_NONE, "jw:resume");
	}
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
	return rv;
}
#endif /* JOBS */

/* are there any running or stopped jobs ? */
int
j_stopped_running()
{
	Job	*j;
	int	which = 0;

	for (j = job_list; j != (Job *) 0; j = j->next) {
#ifdef JOBS
		if (j->ppid == procpid && j->state == PSTOPPED)
			which |= 1;
#endif /* JOBS */
		if (Flag(FLOGIN) && !Flag(FNOHUP) && procpid == kshpid
		    && j->ppid == procpid && j->state == PRUNNING)
			which |= 2;
	}
	if (which) {
		shellf("You have %s%s%s jobs\n",
			which & 1 ? "stopped" : "",
			which == 3 ? " and " : "",
			which & 2 ? "running" : "");
		return 1;
	}

	return 0;
}

/* list jobs for jobs built-in */
int
j_jobs(cp, slp, nflag)
	const char *cp;
	int	slp;		/* 0: short, 1: long, 2: pgrp */
	int	nflag;
{
	Job	*j, *tmp;
	int	how;
	int	zflag = 0;
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */

	if (nflag < 0) { /* kludge: print zombies */
		nflag = 0;
		zflag = 1;
	}
	if (cp) {
		int	ecode;

		if ((j = j_lookup(cp, &ecode)) == (Job *) 0) {
#ifdef JOB_SIGS
			sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
			bi_errorf("%s: %s", cp, lookup_msgs[ecode]);
			return 1;
		}
	} else
		j = job_list;
	how = slp == 0 ? JP_MEDIUM : (slp == 1 ? JP_LONG : JP_PGRP);
	for (; j; j = j->next) {
		if ((!(j->flags & JF_ZOMBIE) || zflag)
		    && (!nflag || (j->flags & JF_CHANGED)))
		{
			j_print(j, how, shl_stdout);
			if (j->state == PEXITED || j->state == PSIGNALLED)
				j->flags |= JF_REMOVE;
		}
		if (cp)
			break;
	}
	/* Remove jobs after printing so there won't be multiple + or - jobs */
	for (j = job_list; j; j = tmp) {
		tmp = j->next;
		if (j->flags & JF_REMOVE)
			remove_job(j, "jobs");
	}
#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
	return 0;
}

/* list jobs for top-level notification */
void
j_notify()
{
	Job	*j, *tmp;
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */
	for (j = job_list; j; j = j->next) {
#ifdef JOBS
		if (Flag(FMONITOR) && (j->flags & JF_CHANGED))
			j_print(j, JP_MEDIUM, shl_out);
#endif /* JOBS */
		/* Remove job after doing reports so there aren't
		 * multiple +/- jobs.
		 */
		if (j->state == PEXITED || j->state == PSIGNALLED)
			j->flags |= JF_REMOVE;
	}
	for (j = job_list; j; j = tmp) {
		tmp = j->next;
		if (j->flags & JF_REMOVE)
			remove_job(j, "notify");
	}
	shf_flush(shl_out);
#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */
}

/* Return pid of last process in last asynchornous job */
pid_t
j_async()
{
#ifdef JOB_SIGS
	sigset_t omask;

	sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
#endif /* JOB_SIGS */

	if (async_job)
		async_job->flags |= JF_KNOWN;

#ifdef JOB_SIGS
	sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#endif /* JOB_SIGS */

	return async_pid;
}

/* Make j the last async process
 *
 * If jobs are compiled in then this routine expects sigchld to be blocked.
 */
static void
j_set_async(j)
	Job *j;
{
	Job	*jl, *oldest;

	if (async_job && (async_job->flags & (JF_KNOWN|JF_ZOMBIE)) == JF_ZOMBIE)
		remove_job(async_job, "async");
	if (!(j->flags & JF_STARTED)) {
		internal_errorf(0, "j_async: job not started");
		return;
	}
	async_job = j;
	async_pid = j->last_proc->pid;
	while (nzombie > child_max) {
		oldest = (Job *) 0;
		for (jl = job_list; jl; jl = jl->next)
			if (jl != async_job && (jl->flags & JF_ZOMBIE)
			    && (!oldest || jl->age < oldest->age))
				oldest = jl;
		if (!oldest) {
			/* XXX debugging */
			if (!(async_job->flags & JF_ZOMBIE) || nzombie != 1) {
				internal_errorf(0, "j_async: bad nzombie (%d)", nzombie);
				nzombie = 0;
			}
			break;
		}
		remove_job(oldest, "zombie");
	}
}

/* Start a job: set STARTED, check for held signals and set j->last_proc
 *
 * If jobs are compiled in then this routine expects sigchld to be blocked.
 */
static void
j_startjob(j)
	Job *j;
{
	Proc	*p;

	j->flags |= JF_STARTED;
	for (p = j->proc_list; p->next; p = p->next)
		;
	j->last_proc = p;

#ifdef NEED_PGRP_SYNC
	if (j_sync_open) {
		j_sync_open = 0;
		closepipe(j_sync_pipe);
	}
#endif /* NEED_PGRP_SYNC */
#ifdef JOB_SIGS
	if (held_sigchld) {
		held_sigchld = 0;
		/* Don't call j_sigchld() as it may remove job... */
		kill(procpid, SIGCHLD);
	}
#endif /* JOB_SIGS */
}

/*
 * wait for job to complete or change state
 *
 * If jobs are compiled in then this routine expects sigchld to be blocked.
 */
static int
j_waitj(j, flags, where)
	Job	*j;
	int	flags;		/* see JW_* */
	const char *where;
{
	int	rv;

	/*
	 * No auto-notify on the job we are waiting on.
	 */
	j->flags |= JF_WAITING;
	if (flags & JW_ASYNCNOTIFY)
		j->flags |= JF_W_ASYNCNOTIFY;

	if (!Flag(FMONITOR))
		flags |= JW_STOPPEDWAIT;

	while ((volatile int) j->state == PRUNNING
		|| ((flags & JW_STOPPEDWAIT)
		    && (volatile int) j->state == PSTOPPED))
	{
#ifdef JOB_SIGS
		sigsuspend(&sm_default);
#else /* JOB_SIGS */
		j_sigchld(SIGCHLD);
#endif /* JOB_SIGS */
		if (fatal_trap) {
			int oldf = j->flags & (JF_WAITING|JF_W_ASYNCNOTIFY);
			j->flags &= ~(JF_WAITING|JF_W_ASYNCNOTIFY);
			runtraps(TF_FATAL);
			j->flags |= oldf; /* not reached... */
		}
		if ((flags & JW_INTERRUPT) && (rv = trap_pending())) {
			j->flags &= ~(JF_WAITING|JF_W_ASYNCNOTIFY);
			return -rv;
		}
	}
	j->flags &= ~(JF_WAITING|JF_W_ASYNCNOTIFY);

	if (j->flags & JF_FG) {
		WAIT_T	status;

		j->flags &= ~JF_FG;
#ifdef TTY_PGRP
		if (Flag(FMONITOR) && ttypgrp_ok && j->pgrp) {
			/*
			 * Save the tty's current pgrp so it can be restored
			 * when the job is foregrounded.  This is to
			 * deal with things like the GNU su which does
			 * a fork/exec instead of an exec (the fork means
			 * the execed shell gets a different pid from its
			 * pgrp, so naturally it sets its pgrp and gets hosed
			 * when it gets forgrounded by the parent shell, which
			 * has restored the tty's pgrp to that of the su
			 * process).
			 */
			if (j->state == PSTOPPED
			    && (j->saved_ttypgrp = tcgetpgrp(tty_fd)) >= 0)
				j->flags |= JF_SAVEDTTYPGRP;
			if (tcsetpgrp(tty_fd, our_pgrp) < 0) {
				warningf(TRUE,
				"j_waitj: tcsetpgrp(%d, %d) failed: %s",
					tty_fd, (int) our_pgrp,
					strerror(errno));
			}
			if (j->state == PSTOPPED) {
				j->flags |= JF_SAVEDTTY;
				get_tty(tty_fd, &j->ttystate);
			}
		}
#endif /* TTY_PGRP */
		if (tty_fd >= 0) {
			/* Only restore tty settings if job was originally
			 * started in the foreground.  Problems can be
			 * caused by things like `more foobar &' which will
			 * typically get and save the shell's vi/emacs tty
			 * settings before setting up the tty for itself;
			 * when more exits, it restores the `original'
			 * settings, and things go down hill from there...
			 */
			if (j->state == PEXITED && j->status == 0
			    && (j->flags & JF_USETTYMODE))
			{
				get_tty(tty_fd, &tty_state);
			} else {
				set_tty(tty_fd, &tty_state,