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07f490ac97
freebsd-nq/bin/sh/jobs.c
Jilles Tjoelker d70ad6f2d0 sh: Recognize "--" and explicitly reject options in wait builtin. 
If syntactically invalid job identifiers are to be taken as jobs that exited
with status 127, this should not apply to options, so that we can add
options later if need be.
2013-03-15 20:29:31 +00:00

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/*-
* 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.
* 4. 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include "shell.h"
#if JOBS
#include <termios.h>
#undef CEOF /* syntax.h redefines this */
#endif
#include "redir.h"
#include "exec.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"
#include "var.h"
#include "builtins.h"
static struct job *jobtab; /* array of jobs */
static int njobs; /* size of array */
MKINIT pid_t backgndpid = -1; /* pid of last background process */
MKINIT struct job *bgjob = NULL; /* last background process */
#if JOBS
static struct job *jobmru; /* most recently used job list */
static pid_t initialpgrp; /* pgrp of shell on invocation */
#endif
int in_waitcmd = 0; /* are we in waitcmd()? */
volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */
static int ttyfd = -1;
/* mode flags for dowait */
#define DOWAIT_BLOCK 0x1 /* wait until a child exits */
#define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signals */
#if JOBS
static void restartjob(struct job *);
#endif
static void freejob(struct job *);
static struct job *getjob(char *);
pid_t getjobpgrp(char *);
static pid_t dowait(int, struct job *);
static void checkzombies(void);
static void cmdtxt(union node *);
static void cmdputs(const char *);
#if JOBS
static void setcurjob(struct job *);
static void deljob(struct job *);
static struct job *getcurjob(struct job *);
#endif
static void printjobcmd(struct job *);
static void showjob(struct job *, int);
/*
* Turn job control on and off.
*/
MKINIT int jobctl;
#if JOBS
void
setjobctl(int on)
{
int i;
if (on == jobctl || rootshell == 0)
return;
if (on) {
if (ttyfd != -1)
close(ttyfd);
if ((ttyfd = open(_PATH_TTY, O_RDWR)) < 0) {
i = 0;
while (i <= 2 && !isatty(i))
i++;
if (i > 2 || (ttyfd = fcntl(i, F_DUPFD, 10)) < 0)
goto out;
}
if (ttyfd < 10) {
/*
* Keep our TTY file descriptor out of the way of
* the user's redirections.
*/
if ((i = fcntl(ttyfd, F_DUPFD, 10)) < 0) {
close(ttyfd);
ttyfd = -1;
goto out;
}
close(ttyfd);
ttyfd = i;
}
if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) {
close(ttyfd);
ttyfd = -1;
goto out;
}
do { /* while we are in the background */
initialpgrp = tcgetpgrp(ttyfd);
if (initialpgrp < 0) {
out: out2fmt_flush("sh: can't access tty; job control turned off\n");
mflag = 0;
return;
}
if (initialpgrp != getpgrp()) {
kill(0, SIGTTIN);
continue;
}
} while (0);
setsignal(SIGTSTP);
setsignal(SIGTTOU);
setsignal(SIGTTIN);
setpgid(0, rootpid);
tcsetpgrp(ttyfd, rootpid);
} else { /* turning job control off */
setpgid(0, initialpgrp);
tcsetpgrp(ttyfd, initialpgrp);
close(ttyfd);
ttyfd = -1;
setsignal(SIGTSTP);
setsignal(SIGTTOU);
setsignal(SIGTTIN);
}
jobctl = on;
}
#endif
#if JOBS
int
fgcmd(int argc __unused, char **argv)
{
struct job *jp;
pid_t pgrp;
int status;
jp = getjob(argv[1]);
if (jp->jobctl == 0)
error("job not created under job control");
printjobcmd(jp);
flushout(&output);
pgrp = jp->ps[0].pid;
tcsetpgrp(ttyfd, pgrp);
restartjob(jp);
jp->foreground = 1;
INTOFF;
status = waitforjob(jp, (int *)NULL);
INTON;
return status;
}
int
bgcmd(int argc, char **argv)
{
struct job *jp;
do {
jp = getjob(*++argv);
if (jp->jobctl == 0)
error("job not created under job control");
if (jp->state == JOBDONE)
continue;
restartjob(jp);
jp->foreground = 0;
out1fmt("[%td] ", jp - jobtab + 1);
printjobcmd(jp);
} while (--argc > 1);
return 0;
}
static void
restartjob(struct job *jp)
{
struct procstat *ps;
int i;
if (jp->state == JOBDONE)
return;
setcurjob(jp);
INTOFF;
kill(-jp->ps[0].pid, SIGCONT);
for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
if (WIFSTOPPED(ps->status)) {
ps->status = -1;
jp->state = 0;
}
}
INTON;
}
#endif
int
jobscmd(int argc __unused, char *argv[] __unused)
{
char *id;
int ch, mode;
mode = SHOWJOBS_DEFAULT;
while ((ch = nextopt("lps")) != '\0') {
switch (ch) {
case 'l':
mode = SHOWJOBS_VERBOSE;
break;
case 'p':
mode = SHOWJOBS_PGIDS;
break;
case 's':
mode = SHOWJOBS_PIDS;
break;
}
}
if (*argptr == NULL)
showjobs(0, mode);
else
while ((id = *argptr++) != NULL)
showjob(getjob(id), mode);
return (0);
}
static void
printjobcmd(struct job *jp)
{
struct procstat *ps;
int i;
for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
out1str(ps->cmd);
if (i > 0)
out1str(" | ");
}
out1c('\n');
}
static void
showjob(struct job *jp, int mode)
{
char s[64];
char statestr[64];
const char *sigstr;
struct procstat *ps;
struct job *j;
int col, curr, i, jobno, prev, procno;
char c;
procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs;
jobno = jp - jobtab + 1;
curr = prev = 0;
#if JOBS
if ((j = getcurjob(NULL)) != NULL) {
curr = j - jobtab + 1;
if ((j = getcurjob(j)) != NULL)
prev = j - jobtab + 1;
}
#endif
ps = jp->ps + jp->nprocs - 1;
if (jp->state == 0) {
strcpy(statestr, "Running");
#if JOBS
} else if (jp->state == JOBSTOPPED) {
while (!WIFSTOPPED(ps->status) && ps > jp->ps)
ps--;
if (WIFSTOPPED(ps->status))
i = WSTOPSIG(ps->status);
else
i = -1;
sigstr = strsignal(i);
if (sigstr != NULL)
strcpy(statestr, sigstr);
else
strcpy(statestr, "Suspended");
#endif
} else if (WIFEXITED(ps->status)) {
if (WEXITSTATUS(ps->status) == 0)
strcpy(statestr, "Done");
else
fmtstr(statestr, 64, "Done(%d)",
WEXITSTATUS(ps->status));
} else {
i = WTERMSIG(ps->status);
sigstr = strsignal(i);
if (sigstr != NULL)
strcpy(statestr, sigstr);
else
strcpy(statestr, "Unknown signal");
if (WCOREDUMP(ps->status))
strcat(statestr, " (core dumped)");
}
for (ps = jp->ps ; ; ps++) { /* for each process */
if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
out1fmt("%d\n", (int)ps->pid);
goto skip;
}
if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
goto skip;
if (jobno == curr && ps == jp->ps)
c = '+';
else if (jobno == prev && ps == jp->ps)
c = '-';
else
c = ' ';
if (ps == jp->ps)
fmtstr(s, 64, "[%d] %c ", jobno, c);
else
fmtstr(s, 64, " %c ", c);
out1str(s);
col = strlen(s);
if (mode == SHOWJOBS_VERBOSE) {
fmtstr(s, 64, "%d ", (int)ps->pid);
out1str(s);
col += strlen(s);
}
if (ps == jp->ps) {
out1str(statestr);
col += strlen(statestr);
}
do {
out1c(' ');
col++;
} while (col < 30);
if (mode == SHOWJOBS_VERBOSE) {
out1str(ps->cmd);
out1c('\n');
} else
printjobcmd(jp);
skip: if (--procno <= 0)
break;
}
}
/*
* 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(int change, int mode)
{
int jobno;
struct job *jp;
TRACE(("showjobs(%d) called\n", change));
checkzombies();
for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
if (! jp->used)
continue;
if (jp->nprocs == 0) {
freejob(jp);
continue;
}
if (change && ! jp->changed)
continue;
showjob(jp, mode);
jp->changed = 0;
/* Hack: discard jobs for which $! has not been referenced
* in interactive mode when they terminate.
*/
if (jp->state == JOBDONE && !jp->remembered &&
(iflag || jp != bgjob)) {
freejob(jp);
}
}
}
/*
* Mark a job structure as unused.
*/
static void
freejob(struct job *jp)
{
struct procstat *ps;
int i;
INTOFF;
if (bgjob == jp)
bgjob = NULL;
for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
if (ps->cmd != nullstr)
ckfree(ps->cmd);
}
if (jp->ps != &jp->ps0)
ckfree(jp->ps);
jp->used = 0;
#if JOBS
deljob(jp);
#endif
INTON;
}
int
waitcmd(int argc __unused, char **argv __unused)
{
struct job *job;
int status, retval;
struct job *jp;
nextopt("");
if (*argptr != NULL) {
job = getjob(*argptr);
} else {
job = NULL;
}
/*
* Loop until a process is terminated or stopped, or a SIGINT is
* received.
*/
in_waitcmd++;
do {
if (job != NULL) {
if (job->state) {
status = job->ps[job->nprocs - 1].status;
if (WIFEXITED(status))
retval = WEXITSTATUS(status);
#if JOBS
else if (WIFSTOPPED(status))
retval = WSTOPSIG(status) + 128;
#endif
else
retval = WTERMSIG(status) + 128;
if (! iflag || ! job->changed)
freejob(job);
else {
job->remembered = 0;
if (job == bgjob)
bgjob = NULL;
}
in_waitcmd--;
return retval;
}
} else {
for (jp = jobtab ; jp < jobtab + njobs; jp++)
if (jp->used && jp->state == JOBDONE) {
if (! iflag || ! jp->changed)
freejob(jp);
else {
jp->remembered = 0;
if (jp == bgjob)
bgjob = NULL;
}
}
for (jp = jobtab ; ; jp++) {
if (jp >= jobtab + njobs) { /* no running procs */
in_waitcmd--;
return 0;
}
if (jp->used && jp->state == 0)
break;
}
}
} while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1);
in_waitcmd--;
return pendingsig + 128;
}
int
jobidcmd(int argc __unused, char **argv)
{
struct job *jp;
int i;
jp = getjob(argv[1]);
for (i = 0 ; i < jp->nprocs ; ) {
out1fmt("%d", (int)jp->ps[i].pid);
out1c(++i < jp->nprocs? ' ' : '\n');
}
return 0;
}
/*
* Convert a job name to a job structure.
*/
static struct job *
getjob(char *name)
{
int jobno;
struct job *found, *jp;
pid_t pid;
int i;
if (name == NULL) {
#if JOBS
currentjob: if ((jp = getcurjob(NULL)) == NULL)
error("No current job");
return (jp);
#else
error("No current job");
#endif
} else if (name[0] == '%') {
if (is_digit(name[1])) {
jobno = number(name + 1);
if (jobno > 0 && jobno <= njobs
&& jobtab[jobno - 1].used != 0)
return &jobtab[jobno - 1];
#if JOBS
} else if (name[1] == '%' && name[2] == '\0') {
goto currentjob;
} else if (name[1] == '+' && name[2] == '\0') {
goto currentjob;
} else if (name[1] == '-' && name[2] == '\0') {
if ((jp = getcurjob(NULL)) == NULL ||
(jp = getcurjob(jp)) == NULL)
error("No previous job");
return (jp);
#endif
} else if (name[1] == '?') {
found = NULL;
for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
if (jp->used && jp->nprocs > 0
&& strstr(jp->ps[0].cmd, name + 2) != NULL) {
if (found)
error("%s: ambiguous", name);
found = jp;
}
}
if (found != NULL)
return (found);
} else {
found = NULL;
for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
if (jp->used && jp->nprocs > 0
&& prefix(name + 1, jp->ps[0].cmd)) {
if (found)
error("%s: ambiguous", name);
found = jp;
}
}
if (found)
return found;
}
} else if (is_number(name)) {
pid = (pid_t)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;
}
}
error("No such job: %s", name);
/*NOTREACHED*/
return NULL;
}
pid_t
getjobpgrp(char *name)
{
struct job *jp;
jp = getjob(name);
return -jp->ps[0].pid;
}
/*
* Return a new job structure,
*/
struct job *
makejob(union node *node __unused, int nprocs)
{
int i;
struct job *jp;
for (i = njobs, jp = jobtab ; ; jp++) {
if (--i < 0) {
INTOFF;
if (njobs == 0) {
jobtab = ckmalloc(4 * sizeof jobtab[0]);
#if JOBS
jobmru = NULL;
#endif
} else {
jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
memcpy(jp, jobtab, njobs * sizeof jp[0]);
#if JOBS
/* Relocate `next' pointers and list head */
if (jobmru != NULL)
jobmru = &jp[jobmru - jobtab];
for (i = 0; i < njobs; i++)
if (jp[i].next != NULL)
jp[i].next = &jp[jp[i].next -
jobtab];
#endif
if (bgjob != NULL)
bgjob = &jp[bgjob - jobtab];
/* 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 = 0;
jp->used = 1;
jp->changed = 0;
jp->nprocs = 0;
jp->foreground = 0;
jp->remembered = 0;
#if JOBS
jp->jobctl = jobctl;
jp->next = NULL;
#endif
if (nprocs > 1) {
jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
} else {
jp->ps = &jp->ps0;
}
INTON;
TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
jp - jobtab + 1));
return jp;
}
#if JOBS
static void
setcurjob(struct job *cj)
{
struct job *jp, *prev;
for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
if (jp == cj) {
if (prev != NULL)
prev->next = jp->next;
else
jobmru = jp->next;
jp->next = jobmru;
jobmru = cj;
return;
}
}
cj->next = jobmru;
jobmru = cj;
}
static void
deljob(struct job *j)
{
struct job *jp, *prev;
for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
if (jp == j) {
if (prev != NULL)
prev->next = jp->next;
else
jobmru = jp->next;
return;
}
}
}
/*
* Return the most recently used job that isn't `nj', and preferably one
* that is stopped.
*/
static struct job *
getcurjob(struct job *nj)
{
struct job *jp;
/* Try to find a stopped one.. */
for (jp = jobmru; jp != NULL; jp = jp->next)
if (jp->used && jp != nj && jp->state == JOBSTOPPED)
return (jp);
/* Otherwise the most recently used job that isn't `nj' */
for (jp = jobmru; jp != NULL; jp = jp->next)
if (jp->used && jp != nj)
return (jp);
return (NULL);
}
#endif
/*
* Fork of 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).
*/
pid_t
forkshell(struct job *jp, union node *n, int mode)
{
pid_t pid;
pid_t pgrp;
TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
mode));
INTOFF;
if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
checkzombies();
flushall();
pid = fork();
if (pid == -1) {
TRACE(("Fork failed, errno=%d\n", errno));
INTON;
error("Cannot fork: %s", strerror(errno));
}
if (pid == 0) {
struct job *p;
int wasroot;
int i;
TRACE(("Child shell %d\n", (int)getpid()));
wasroot = rootshell;
rootshell = 0;
handler = &main_handler;
closescript();
INTON;
forcelocal = 0;
clear_traps();
#if JOBS
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;
if (setpgid(0, pgrp) == 0 && mode == FORK_FG) {
/*** this causes superfluous TIOCSPGRPS ***/
if (tcsetpgrp(ttyfd, pgrp) < 0)
error("tcsetpgrp failed, errno=%d", errno);
}
setsignal(SIGTSTP);
setsignal(SIGTTOU);
} else if (mode == FORK_BG) {
ignoresig(SIGINT);
ignoresig(SIGQUIT);
if ((jp == NULL || jp->nprocs == 0) &&
! fd0_redirected_p ()) {
close(0);
if (open(_PATH_DEVNULL, O_RDONLY) != 0)
error("cannot open %s: %s",
_PATH_DEVNULL, strerror(errno));
}
}
#else
if (mode == FORK_BG) {
ignoresig(SIGINT);
ignoresig(SIGQUIT);
if ((jp == NULL || jp->nprocs == 0) &&
! fd0_redirected_p ()) {
close(0);
if (open(_PATH_DEVNULL, O_RDONLY) != 0)
error("cannot open %s: %s",
_PATH_DEVNULL, strerror(errno));
}
}
#endif
INTOFF;
for (i = njobs, p = jobtab ; --i >= 0 ; p++)
if (p->used)
freejob(p);
INTON;
if (wasroot && iflag) {
setsignal(SIGINT);
setsignal(SIGQUIT);
setsignal(SIGTERM);
}
return pid;
}
if (rootshell && mode != FORK_NOJOB && mflag) {
if (jp == NULL || jp->nprocs == 0)
pgrp = pid;
else
pgrp = jp->ps[0].pid;
setpgid(pid, pgrp);
}
if (mode == FORK_BG) {
if (bgjob != NULL && bgjob->state == JOBDONE &&
!bgjob->remembered && !iflag)
freejob(bgjob);
backgndpid = pid; /* set $! */
bgjob = jp;
}
if (jp) {
struct procstat *ps = &jp->ps[jp->nprocs++];
ps->pid = pid;
ps->status = -1;
ps->cmd = nullstr;
if (iflag && rootshell && n)
ps->cmd = commandtext(n);
jp->foreground = mode == FORK_FG;
#if JOBS
setcurjob(jp);
#endif
}
INTON;
TRACE(("In parent shell: child = %d\n", (int)pid));
return pid;
}
pid_t
vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
{
pid_t pid;
struct jmploc jmploc;
struct jmploc *savehandler;
TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
(void *)pip));
INTOFF;
flushall();
savehandler = handler;
pid = vfork();
if (pid == -1) {
TRACE(("Vfork failed, errno=%d\n", errno));
INTON;
error("Cannot fork: %s", strerror(errno));
}
if (pid == 0) {
TRACE(("Child shell %d\n", (int)getpid()));
if (setjmp(jmploc.loc))
_exit(exception == EXEXEC ? exerrno : 2);
if (pip != NULL) {
close(pip[0]);
if (pip[1] != 1) {
dup2(pip[1], 1);
close(pip[1]);
}
}
handler = &jmploc;
shellexec(argv, envp, path, idx);
}
handler = savehandler;
if (jp) {
struct procstat *ps = &jp->ps[jp->nprocs++];
ps->pid = pid;
ps->status = -1;
ps->cmd = nullstr;
jp->foreground = 1;
#if JOBS
setcurjob(jp);
#endif
}
INTON;
TRACE(("In parent shell: child = %d\n", (int)pid));
return pid;
}
/*
* 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
* foreground 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, int *origstatus)
{
#if JOBS
pid_t mypgrp = getpgrp();
int propagate_int = jp->jobctl && jp->foreground;
#endif
int status;
int st;
INTOFF;
TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
while (jp->state == 0)
if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG : 0), jp) == -1)
dotrap();
#if JOBS
if (jp->jobctl) {
if (tcsetpgrp(ttyfd, mypgrp) < 0)
error("tcsetpgrp failed, errno=%d\n", errno);
}
if (jp->state == JOBSTOPPED)
setcurjob(jp);
#endif
status = jp->ps[jp->nprocs - 1].status;
if (origstatus != NULL)
*origstatus = 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;
if (! JOBS || jp->state == JOBDONE)
freejob(jp);
if (int_pending()) {
if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
CLEAR_PENDING_INT;
}
#if JOBS
else if (rootshell && iflag && propagate_int &&
WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
kill(getpid(), SIGINT);
#endif
INTON;
return st;
}
static void
dummy_handler(int sig)
{
}
/*
* Wait for a process to terminate.
*/
static pid_t
dowait(int mode, struct job *job)
{
struct sigaction sa, osa;
sigset_t mask, omask;
pid_t pid;
int status;
struct procstat *sp;
struct job *jp;
struct job *thisjob;
const char *sigstr;
int done;
int stopped;
int sig;
int coredump;
int wflags;
int restore_sigchld;
TRACE(("dowait(%d, %p) called\n", mode, job));
restore_sigchld = 0;
if ((mode & DOWAIT_SIG) != 0) {
sigfillset(&mask);
sigprocmask(SIG_BLOCK, &mask, &omask);
INTOFF;
if (!issigchldtrapped()) {
restore_sigchld = 1;
sa.sa_handler = dummy_handler;
sa.sa_flags = 0;
sigemptyset(&sa.sa_mask);
sigaction(SIGCHLD, &sa, &osa);
}
}
do {
#if JOBS
if (iflag)
wflags = WUNTRACED | WCONTINUED;
else
#endif
wflags = 0;
if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
wflags |= WNOHANG;
pid = wait3(&status, wflags, (struct rusage *)NULL);
TRACE(("wait returns %d, status=%d\n", (int)pid, status));
if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
sigsuspend(&omask);
pid = -1;
if (int_pending())
break;
}
} while (pid == -1 && errno == EINTR && breakwaitcmd == 0);
if (pid == -1 && errno == ECHILD && job != NULL)
job->state = JOBDONE;
if ((mode & DOWAIT_SIG) != 0) {
if (restore_sigchld)
sigaction(SIGCHLD, &osa, NULL);
sigprocmask(SIG_SETMASK, &omask, NULL);
INTON;
}
if (breakwaitcmd != 0) {
breakwaitcmd = 0;
if (pid <= 0)
return -1;
}
if (pid <= 0)
return pid;
INTOFF;
thisjob = NULL;
for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
if (jp->used && jp->nprocs > 0) {
done = 1;
stopped = 1;
for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
if (sp->pid == -1)
continue;
if (sp->pid == pid) {
TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
(int)pid, sp->status,
status));
if (WIFCONTINUED(status)) {
sp->status = -1;
jp->state = 0;
} else
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 %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
jp->state = state;
if (jp != job) {
if (done && !jp->remembered &&
!iflag && jp != bgjob)
freejob(jp);
#if JOBS
else if (done)
deljob(jp);
#endif
}
}
}
}
}
INTON;
if (!thisjob || thisjob->state == 0)
;
else if ((!rootshell || !iflag || thisjob == job) &&
thisjob->foreground && thisjob->state != JOBSTOPPED) {
sig = 0;
coredump = 0;
for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
if (WIFSIGNALED(sp->status)) {
sig = WTERMSIG(sp->status);
coredump = WCOREDUMP(sp->status);
}
if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
sigstr = strsignal(sig);
if (sigstr != NULL)
out2str(sigstr);
else
out2str("Unknown signal");
if (coredump)
out2str(" (core dumped)");
out2c('\n');
flushout(out2);
}
} else {
TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
thisjob->changed = 1;
}
return pid;
}
/*
* return 1 if there are stopped jobs, otherwise 0
*/
int job_warning = 0;
int
stoppedjobs(void)
{
int jobno;
struct job *jp;
if (job_warning)
return (0);
for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
if (jp->used == 0)
continue;
if (jp->state == JOBSTOPPED) {
out2fmt_flush("You have stopped jobs.\n");
job_warning = 2;
return (1);
}
}
return (0);
}
static void
checkzombies(void)
{
while (njobs > 0 && dowait(0, NULL) > 0)
;
}
int
backgndpidset(void)
{
return backgndpid != -1;
}
pid_t
backgndpidval(void)
{
if (bgjob != NULL && !forcelocal)
bgjob->remembered = 1;
return backgndpid;
}
/*
* Return a string identifying a command (to be printed by the
* jobs command.
*/
static char *cmdnextc;
static int cmdnleft;
#define MAXCMDTEXT 200
char *
commandtext(union node *n)
{
char *name;
cmdnextc = name = ckmalloc(MAXCMDTEXT);
cmdnleft = MAXCMDTEXT - 4;
cmdtxt(n);
*cmdnextc = '\0';
return name;
}
static void
cmdtxt(union node *n)
{
union node *np;
struct nodelist *lp;
const char *p;
int i;
char s[2];
if (n == NULL)
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);
cmdputs("...");
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 ...");
break;
case NCASE:
cmdputs("case ");
cmdputs(n->ncase.expr->narg.text);
cmdputs(" in ...");
break;
case NDEFUN:
cmdputs(n->narg.text);
cmdputs("() ...");
break;
case NNOT:
cmdputs("! ");
cmdtxt(n->nnot.com);
break;
case NCMD:
for (np = n->ncmd.args ; np ; np = np->narg.next) {
cmdtxt(np);
if (np->narg.next)
cmdputs(" ");
}
for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
cmdputs(" ");
cmdtxt(np);
}
break;
case NARG:
cmdputs(n->narg.text);
break;
case NTO:
p = ">"; i = 1; goto redir;
case NAPPEND:
p = ">>"; i = 1; goto redir;
case NTOFD:
p = ">&"; i = 1; goto redir;
case NCLOBBER:
p = ">|"; i = 1; goto redir;
case NFROM:
p = "<"; i = 0; goto redir;
case NFROMTO:
p = "<>"; i = 0; goto redir;
case NFROMFD:
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) {
if (n->ndup.dupfd >= 0)
s[0] = n->ndup.dupfd + '0';
else
s[0] = '-';
s[1] = '\0';
cmdputs(s);
} else {
cmdtxt(n->nfile.fname);
}
break;
case NHERE:
case NXHERE:
cmdputs("<<...");
break;
default:
cmdputs("???");
break;
}
}
static void
cmdputs(const char *s)
{
const char *p;
char *q;
char c;
int subtype = 0;
if (cmdnleft <= 0)
return;
p = s;
q = cmdnextc;
while ((c = *p++) != '\0') {
if (c == CTLESC)
*q++ = *p++;
else if (c == CTLVAR) {
*q++ = '$';
if (--cmdnleft > 0)
*q++ = '{';
subtype = *p++;
if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
*q++ = '#';
} else if (c == '=' && subtype != 0) {
*q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
if (*q)
q++;
else
cmdnleft++;
if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
(subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
--cmdnleft > 0)
*q = q[-1], q++;
subtype = 0;
} else if (c == CTLENDVAR) {
*q++ = '}';
} else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
cmdnleft -= 5;
if (cmdnleft > 0) {
*q++ = '$';
*q++ = '(';
*q++ = '.';
*q++ = '.';
*q++ = '.';
*q++ = ')';
}
} else if (c == CTLARI) {
cmdnleft -= 2;
if (cmdnleft > 0) {
*q++ = '$';
*q++ = '(';
*q++ = '(';
}
p++;
} else if (c == CTLENDARI) {
if (--cmdnleft > 0) {
*q++ = ')';
*q++ = ')';
}
} else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
cmdnleft++; /* ignore */
else
*q++ = c;
if (--cmdnleft <= 0) {
*q++ = '.';
*q++ = '.';
*q++ = '.';
break;
}
}
cmdnextc = q;
}
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