sanchayanmaity/minix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
minix/bin/sh/jobs.c

1528 lines
32 KiB
C
Raw Normal View History

Importing bin/sh /etc/profile enables by default tabcompletion, as well as emacs mode, in order to keep the old MINIX ash behavior. Note: The shell now refuses to source a script without a relative or absolute path. This means: - '. myscript.sh' fails, while - '. ./myscript.sh' succeeds Change-Id: I0be89b0747bd005e4c05cadb937af86883627dc6
2014-08-03 23:10:41 +02:00
/* $NetBSD: jobs.c,v 1.71 2012/12/31 14:10:15 dsl 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 1.71 2012/12/31 14:10:15 dsl Exp $");
#endif
#endif /* not lint */
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <paths.h>
#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/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 "builtins.h"
#include "trap.h"
#include "syntax.h"
#include "input.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "mystring.h"
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
#if JOBS && defined(__minix)
static int ttyfd = -1;
#endif /* JOBS && defined(__minix) */
STATIC void restartjob(struct job *);
STATIC void freejob(struct job *);
STATIC struct job *getjob(const char *, int);
STATIC int dowait(int, struct job *);
#define WBLOCK 1
#define WNOFREE 2
STATIC int waitproc(int, struct job *, int *);
STATIC void cmdtxt(union node *);
STATIC void cmdlist(union node *, int);
STATIC void cmdputs(const char *);
#ifdef SYSV
STATIC int onsigchild(void);
#endif
#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;
#if JOBS /* Minix setjobctl is defined to empty, compilation error */
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);
if (getpgrp() != 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__);
} else { /* turning job control off */
if (getpgrp() != 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__);
close(ttyfd);
ttyfd = -1;
setsignal(SIGTSTP, 0);
setsignal(SIGTTOU, 0);
setsignal(SIGTTIN, 0);
}
jobctl = on;
}
#endif /* JOBS */
#ifdef mkinit
INCLUDE <stdlib.h>
SHELLPROC {
backgndpid = -1;
#if JOBS
jobctl = 0;
#endif
}
#endif
#if JOBS
static int
do_fgcmd(const char *arg_ptr)
{
struct job *jp;
int i;
int status;
jp = getjob(arg_ptr, 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;
}
int
fgcmd(int argc, char **argv)
{
nextopt("");
return do_fgcmd(*argptr);
}
int
fgcmd_percent(int argc, char **argv)
{
nextopt("");
return do_fgcmd(*argv);
}
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;
}
#else
/* LSC: For Minix add dummy functions. */
int
fgcmd(int argc, char **argv)
{
error("no job control in this shell.");
return 1;
}
int
fgcmd_percent(int argc, char **argv)
{
error("no job control in this shell.");
return 1;
}
int
bgcmd(int argc, char **argv)
{
error("no job control in this shell.");
return 1;
}
#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;
#if JOBS /* MINIX: #ifdef fails when JOBS = 0 */
/*
* 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;
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(WBLOCK, NULL) == -1)
return 128 + SIGINT;
jp = jobtab;
}
}
retval = 127; /* XXXGCC: -Wuninitialized */
for (; *argptr; argptr++) {
job = getjob(*argptr, 1);
if (!job) {
retval = 127;
continue;
}
/* loop until process terminated or stopped */
while (job->state == JOBRUNNING) {
if (dowait(WBLOCK|WNOFREE, job) == -1)
return 128 + SIGINT;
}
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 {
/* 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;
#if JOBS /* LSC: not available under MINIX. */
/* 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;
#if JOBS /* LSC: for proper compilation with JOBS == 0 */
int pgrp;
#endif
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;
/* 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__);
}
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(WBLOCK, 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 flags, 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(%x) called\n", flags));
do {
pid = waitproc(flags & WBLOCK, 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 && (flags & WNOFREE) == 0) ||
(job != thisjob && (flags & WNOFREE) != 0))
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 its
* 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 waitpid(-1, status, flags);
#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;
}
Reference in a new issue Copy permalink