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src/bin/ksh/jobs.c

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/* $OpenBSD: jobs.c,v 1.62 2020/07/07 10:33:58 jca Exp $ */
/*
* Process and job control
*/
/*
* Reworked/Rewritten version of Eric Gisin's/Ron Natalie's code by
* Larry Bouzane (larry@cs.mun.ca) and hacked again by
* Michael Rendell (michael@cs.mun.ca)
*
* The interface to the rest of the shell should probably be changed
* to allow use of vfork() when available but that would be way too much
* work :)
*
*/
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "sh.h"
#include "tty.h"
/* Order important! */
#define PRUNNING 0
#define PEXITED 1
#define PSIGNALLED 2
#define PSTOPPED 3
typedef struct proc Proc;
struct proc {
Proc *next; /* next process in pipeline (if any) */
int state;
int status; /* wait status */
pid_t pid; /* process id */
char command[48]; /* process command string */
};
/* Notify/print flag - j_print() argument */
#define JP_NONE 0 /* don't print anything */
#define JP_SHORT 1 /* print signals processes were killed by */
#define JP_MEDIUM 2 /* print [job-num] -/+ command */
#define JP_LONG 3 /* print [job-num] -/+ pid command */
#define JP_PGRP 4 /* print pgrp */
/* put_job() flags */
#define PJ_ON_FRONT 0 /* at very front */
#define PJ_PAST_STOPPED 1 /* just past any stopped jobs */
/* Job.flags values */
#define JF_STARTED 0x001 /* set when all processes in job are started */
#define JF_WAITING 0x002 /* set if j_waitj() is waiting on job */
#define JF_W_ASYNCNOTIFY 0x004 /* set if waiting and async notification ok */
#define JF_XXCOM 0x008 /* set for `command` jobs */
#define JF_FG 0x010 /* running in foreground (also has tty pgrp) */
#define JF_SAVEDTTY 0x020 /* j->ttystate is valid */
#define JF_CHANGED 0x040 /* process has changed state */
#define JF_KNOWN 0x080 /* $! referenced */
#define JF_ZOMBIE 0x100 /* known, unwaited process */
#define JF_REMOVE 0x200 /* flagged for removal (j_jobs()/j_notify()) */
#define JF_USETTYMODE 0x400 /* tty mode saved if process exits normally */
#define JF_SAVEDTTYPGRP 0x800 /* j->saved_ttypgrp is valid */
#define JF_PIPEFAIL 0x1000 /* pipefail on when job was started */
typedef struct job Job;
struct job {
Job *next; /* next job in list */
int job; /* job number: %n */
int flags; /* see JF_* */
int state; /* job state */
int status; /* exit status of last process */
pid_t pgrp; /* process group of job */
pid_t ppid; /* pid of process that forked job */
int age; /* number of jobs started */
struct timeval systime; /* system time used by job */
struct timeval usrtime; /* user time used by job */
Proc *proc_list; /* process list */
Proc *last_proc; /* last process in list */
Coproc_id coproc_id; /* 0 or id of coprocess output pipe */
struct termios ttystate;/* saved tty state for stopped jobs */
pid_t saved_ttypgrp; /* saved tty process group for stopped jobs */
};
/* Flags for j_waitj() */
#define JW_NONE 0x00
#define JW_INTERRUPT 0x01 /* ^C will stop the wait */
#define JW_ASYNCNOTIFY 0x02 /* asynchronous notification during wait ok */
#define JW_STOPPEDWAIT 0x04 /* wait even if job stopped */
/* Error codes for j_lookup() */
#define JL_OK 0
#define JL_NOSUCH 1 /* no such job */
#define JL_AMBIG 2 /* %foo or %?foo is ambiguous */
#define JL_INVALID 3 /* non-pid, non-% job id */
static const char *const lookup_msgs[] = {
null,
"no such job",
"ambiguous",
"argument must be %job or process id",
NULL
};
struct timeval j_systime, j_usrtime; /* user and system time of last j_waitjed job */
static Job *job_list; /* job list */
static Job *last_job;
static Job *async_job;
static pid_t async_pid;
static int nzombie; /* # of zombies owned by this process */
int njobs; /* # of jobs started */
static int child_max; /* CHILD_MAX */
/* held_sigchld is set if sigchld occurs before a job is completely started */
static volatile sig_atomic_t held_sigchld;
static struct shf *shl_j;
static int ttypgrp_ok; /* set if can use tty pgrps */
static pid_t restore_ttypgrp = -1;
static pid_t our_pgrp;
static int const tt_sigs[] = { SIGTSTP, SIGTTIN, SIGTTOU };
static void j_set_async(Job *);
static void j_startjob(Job *);
static int j_waitj(Job *, int, const char *);
static void j_sigchld(int);
static void j_print(Job *, int, struct shf *);
static Job *j_lookup(const char *, int *);
static Job *new_job(void);
static Proc *new_proc(void);
static void check_job(Job *);
static void put_job(Job *, int);
static void remove_job(Job *, const char *);
static int kill_job(Job *, int);
/* initialize job control */
void
j_init(int mflagset)
{
child_max = CHILD_MAX; /* so syscon() isn't always being called */
sigemptyset(&sm_default);
sigprocmask(SIG_SETMASK, &sm_default, NULL);
sigemptyset(&sm_sigchld);
sigaddset(&sm_sigchld, SIGCHLD);
setsig(&sigtraps[SIGCHLD], j_sigchld,
SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
if (!mflagset && Flag(FTALKING))
Flag(FMONITOR) = 1;
/* shl_j is used to do asynchronous notification (used in
* an interrupt handler, so need a distinct shf)
*/
shl_j = shf_fdopen(2, SHF_WR, NULL);
if (Flag(FMONITOR) || Flag(FTALKING)) {
int i;
/* the TF_SHELL_USES test is a kludge that lets us know if
* if the signals have been changed by the shell.
*/
for (i = NELEM(tt_sigs); --i >= 0; ) {
sigtraps[tt_sigs[i]].flags |= TF_SHELL_USES;
/* j_change() sets this to SS_RESTORE_DFL if FMONITOR */
setsig(&sigtraps[tt_sigs[i]], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
}
}
/* j_change() calls tty_init() */
if (Flag(FMONITOR))
j_change();
else if (Flag(FTALKING))
tty_init(true);
}
/* suspend the shell */
void
j_suspend(void)
{
struct sigaction sa, osa;
/* Restore tty and pgrp. */
if (ttypgrp_ok) {
tcsetattr(tty_fd, TCSADRAIN, &tty_state);
if (restore_ttypgrp >= 0) {
if (tcsetpgrp(tty_fd, restore_ttypgrp) == -1) {
warningf(false, "%s: tcsetpgrp() failed: %s",
__func__, strerror(errno));
} else {
if (setpgid(0, restore_ttypgrp) == -1) {
warningf(false,
"%s: setpgid() failed: %s",
__func__, strerror(errno));
}
}
}
}
/* Suspend the shell. */
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_handler = SIG_DFL;
sigaction(SIGTSTP, &sa, &osa);
kill(0, SIGTSTP);
/* Back from suspend, reset signals, pgrp and tty. */
sigaction(SIGTSTP, &osa, NULL);
if (ttypgrp_ok) {
if (restore_ttypgrp >= 0) {
if (setpgid(0, kshpid) == -1) {
warningf(false, "%s: setpgid() failed: %s",
__func__, strerror(errno));
ttypgrp_ok = 0;
} else {
if (tcsetpgrp(tty_fd, kshpid) == -1) {
warningf(false,
"%s: tcsetpgrp() failed: %s",
__func__, strerror(errno));
ttypgrp_ok = 0;
}
}
}
tty_init(true);
}
}
/* job cleanup before shell exit */
void
j_exit(void)
{
/* kill stopped, and possibly running, jobs */
Job *j;
int killed = 0;
for (j = job_list; j != NULL; j = j->next) {
if (j->ppid == procpid &&
(j->state == PSTOPPED ||
(j->state == PRUNNING &&
((j->flags & JF_FG) ||
(Flag(FLOGIN) && !Flag(FNOHUP) && procpid == kshpid))))) {
killed = 1;
if (j->pgrp == 0)
kill_job(j, SIGHUP);
else
killpg(j->pgrp, SIGHUP);
if (j->state == PSTOPPED) {
if (j->pgrp == 0)
kill_job(j, SIGCONT);
else
killpg(j->pgrp, SIGCONT);
}
}
}
if (killed)
sleep(1);
j_notify();
if (kshpid == procpid && restore_ttypgrp >= 0) {
/* Need to restore the tty pgrp to what it was when the
* shell started up, so that the process that started us
* will be able to access the tty when we are done.
* Also need to restore our process group in case we are
* about to do an exec so that both our parent and the
* process we are to become will be able to access the tty.
*/
tcsetpgrp(tty_fd, restore_ttypgrp);
setpgid(0, restore_ttypgrp);
}
if (Flag(FMONITOR)) {
Flag(FMONITOR) = 0;
j_change();
}
}
/* turn job control on or off according to Flag(FMONITOR) */
void
j_change(void)
{
int i;
if (Flag(FMONITOR)) {
int use_tty;
if (Flag(FTALKING)) {
/* Don't call tcgetattr() 'til we own the tty process group */
use_tty = 1;
tty_init(false);
} else
use_tty = 0;
/* no controlling tty, no SIGT* */
ttypgrp_ok = use_tty && tty_fd >= 0 && tty_devtty;
if (ttypgrp_ok && (our_pgrp = getpgrp()) < 0) {
warningf(false, "%s: getpgrp() failed: %s",
__func__, strerror(errno));
ttypgrp_ok = 0;
}
if (ttypgrp_ok) {
setsig(&sigtraps[SIGTTIN], SIG_DFL,
SS_RESTORE_ORIG|SS_FORCE);
/* wait to be given tty (POSIX.1, B.2, job control) */
while (1) {
pid_t ttypgrp;
if ((ttypgrp = tcgetpgrp(tty_fd)) == -1) {
warningf(false,
"%s: tcgetpgrp() failed: %s",
__func__, strerror(errno));
ttypgrp_ok = 0;
break;
}
if (ttypgrp == our_pgrp)
break;
kill(0, SIGTTIN);
}
}
for (i = NELEM(tt_sigs); --i >= 0; )
setsig(&sigtraps[tt_sigs[i]], SIG_IGN,
SS_RESTORE_DFL|SS_FORCE);
if (ttypgrp_ok && our_pgrp != kshpid) {
if (setpgid(0, kshpid) == -1) {
warningf(false, "%s: setpgid() failed: %s",
__func__, strerror(errno));
ttypgrp_ok = 0;
} else {
if (tcsetpgrp(tty_fd, kshpid) == -1) {
warningf(false,
"%s: tcsetpgrp() failed: %s",
__func__, strerror(errno));
ttypgrp_ok = 0;
} else
restore_ttypgrp = our_pgrp;
our_pgrp = kshpid;
}
}
if (use_tty) {
if (!ttypgrp_ok)
warningf(false,
"warning: won't have full job control");
}
if (tty_fd >= 0)
tcgetattr(tty_fd, &tty_state);
} else {
ttypgrp_ok = 0;
if (Flag(FTALKING))
for (i = NELEM(tt_sigs); --i >= 0; )
setsig(&sigtraps[tt_sigs[i]], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
else
for (i = NELEM(tt_sigs); --i >= 0; ) {
if (sigtraps[tt_sigs[i]].flags &
(TF_ORIG_IGN | TF_ORIG_DFL))
setsig(&sigtraps[tt_sigs[i]],
(sigtraps[tt_sigs[i]].flags & TF_ORIG_IGN) ?
SIG_IGN : SIG_DFL,
SS_RESTORE_ORIG|SS_FORCE);
}
if (!Flag(FTALKING))
tty_close();
}
}
/* execute tree in child subprocess */
int
exchild(struct op *t, int flags, volatile int *xerrok,
int close_fd) /* used if XPCLOSE or XCCLOSE */
{
static Proc *last_proc; /* for pipelines */
int i;
sigset_t omask;
Proc *p;
Job *j;
int rv = 0;
int forksleep;
int ischild;
if (flags & XEXEC)
/* Clear XFORK|XPCLOSE|XCCLOSE|XCOPROC|XPIPEO|XPIPEI|XXCOM|XBGND
* (also done in another execute() below)
*/
return execute(t, flags & (XEXEC | XERROK), xerrok);
/* no SIGCHLD's while messing with job and process lists */
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
p = new_proc();
p->next = NULL;
p->state = PRUNNING;
p->status = 0;
p->pid = 0;
/* link process into jobs list */
if (flags&XPIPEI) { /* continuing with a pipe */
if (!last_job)
internal_errorf("%s: XPIPEI and no last_job - pid %d",
__func__, (int) procpid);
j = last_job;
last_proc->next = p;
last_proc = p;
} else {
j = new_job(); /* fills in j->job */
/* we don't consider XXCOM's foreground since they don't get
* tty process group and we don't save or restore tty modes.
*/
j->flags = (flags & XXCOM) ? JF_XXCOM :
((flags & XBGND) ? 0 : (JF_FG|JF_USETTYMODE));
if (Flag(FPIPEFAIL))
j->flags |= JF_PIPEFAIL;
timerclear(&j->usrtime);
timerclear(&j->systime);
j->state = PRUNNING;
j->pgrp = 0;
j->ppid = procpid;
j->age = ++njobs;
j->proc_list = p;
j->coproc_id = 0;
last_job = j;
last_proc = p;
put_job(j, PJ_PAST_STOPPED);
}
snptreef(p->command, sizeof(p->command), "%T", t);
/* create child process */
forksleep = 1;
while ((i = fork()) == -1 && errno == EAGAIN && forksleep < 32) {
if (intrsig) /* allow user to ^C out... */
break;
sleep(forksleep);
forksleep <<= 1;
}
if (i == -1) {
kill_job(j, SIGKILL);
remove_job(j, "fork failed");
sigprocmask(SIG_SETMASK, &omask, NULL);
errorf("cannot fork - try again");
}
ischild = i == 0;
if (ischild)
p->pid = procpid = getpid();
else
p->pid = i;
/* job control set up */
if (Flag(FMONITOR) && !(flags&XXCOM)) {
int dotty = 0;
if (j->pgrp == 0) { /* First process */
j->pgrp = p->pid;
dotty = 1;
}
/* set pgrp in both parent and child to deal with race
* condition
*/
setpgid(p->pid, j->pgrp);
/* YYY: should this be
if (ttypgrp_ok && ischild && !(flags&XBGND))
tcsetpgrp(tty_fd, j->pgrp);
instead? (see also YYY below)
*/
if (ttypgrp_ok && dotty && !(flags & XBGND))
tcsetpgrp(tty_fd, j->pgrp);
}
/* used to close pipe input fd */
if (close_fd >= 0 && (((flags & XPCLOSE) && !ischild) ||
((flags & XCCLOSE) && ischild)))
close(close_fd);
if (ischild) { /* child */
/* Do this before restoring signal */
if (flags & XCOPROC)
coproc_cleanup(false);
sigprocmask(SIG_SETMASK, &omask, NULL);
cleanup_parents_env();
/* If FMONITOR or FTALKING is set, these signals are ignored,
* if neither FMONITOR nor FTALKING are set, the signals have
* their inherited values.
*/
if (Flag(FMONITOR) && !(flags & XXCOM)) {
for (i = NELEM(tt_sigs); --i >= 0; )
setsig(&sigtraps[tt_sigs[i]], SIG_DFL,
SS_RESTORE_DFL|SS_FORCE);
}
if (Flag(FBGNICE) && (flags & XBGND))
nice(4);
if ((flags & XBGND) && !Flag(FMONITOR)) {
setsig(&sigtraps[SIGINT], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
setsig(&sigtraps[SIGQUIT], SIG_IGN,
SS_RESTORE_IGN|SS_FORCE);
if (!(flags & (XPIPEI | XCOPROC))) {
int fd = open("/dev/null", O_RDONLY);
if (fd != 0) {
(void) ksh_dup2(fd, 0, true);
close(fd);
}
}
}
remove_job(j, "child"); /* in case of `jobs` command */
nzombie = 0;
ttypgrp_ok = 0;
Flag(FMONITOR) = 0;
Flag(FTALKING) = 0;
tty_close();
cleartraps();
execute(t, (flags & XERROK) | XEXEC, NULL); /* no return */
internal_warningf("%s: execute() returned", __func__);
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 */
/* YYY: Is this needed? (see also YYY above)
if (Flag(FMONITOR) && !(flags&(XXCOM|XBGND)))
tcsetpgrp(tty_fd, j->pgrp);
*/
j_startjob(j);
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 */
}
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");
}
sigprocmask(SIG_SETMASK, &omask, NULL);
return rv;
}
/* start the last job: only used for `command` jobs */
void
startlast(void)
{
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
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);
}
sigprocmask(SIG_SETMASK, &omask, NULL);
}
/* wait for last job: only used for `command` jobs */
int
waitlast(void)
{
int rv;
Job *j;
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
j = last_job;
if (!j || !(j->flags & JF_STARTED)) {
if (!j)
warningf(true, "%s: no last job", __func__);
else
internal_warningf("%s: not started", __func__);
sigprocmask(SIG_SETMASK, &omask, NULL);
return 125; /* not so arbitrary, non-zero value */
}
rv = j_waitj(j, JW_NONE, "jw:waitlast");
sigprocmask(SIG_SETMASK, &omask, NULL);
return rv;
}
/* wait for child, interruptable. */
int
waitfor(const char *cp, int *sigp)
{
int rv;
Job *j;
int ecode;
int flags = JW_INTERRUPT|JW_ASYNCNOTIFY;
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
*sigp = 0;
if (cp == NULL) {
/* 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) {
sigprocmask(SIG_SETMASK, &omask, NULL);
return -1;
}
} else if ((j = j_lookup(cp, &ecode))) {
/* don't report normal job completion */
flags &= ~JW_ASYNCNOTIFY;
if (j->ppid != procpid) {
sigprocmask(SIG_SETMASK, &omask, NULL);
return -1;
}
} else {
sigprocmask(SIG_SETMASK, &omask, NULL);
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");
sigprocmask(SIG_SETMASK, &omask, NULL);
if (rv < 0) /* we were interrupted */
*sigp = 128 + -rv;
return rv;
}
/* kill (built-in) a job */
int
j_kill(const char *cp, int sig)
{
Job *j;
int rv = 0;
int ecode;
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
if ((j = j_lookup(cp, &ecode)) == NULL) {
sigprocmask(SIG_SETMASK, &omask, NULL);
bi_errorf("%s: %s", cp, lookup_msgs[ecode]);
return 1;
}
if (j->pgrp == 0) { /* started when !Flag(FMONITOR) */
if (kill_job(j, sig) < 0) {
bi_errorf("%s: %s", cp, strerror(errno));
rv = 1;
}
} else {
if (j->state == PSTOPPED && (sig == SIGTERM || sig == SIGHUP))
(void) killpg(j->pgrp, SIGCONT);
if (killpg(j->pgrp, sig) == -1) {
bi_errorf("%s: %s", cp, strerror(errno));
rv = 1;
}
}
sigprocmask(SIG_SETMASK, &omask, NULL);
return rv;
}
/* fg and bg built-ins: called only if Flag(FMONITOR) set */
int
j_resume(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)) == NULL) {
sigprocmask(SIG_SETMASK, &omask, NULL);
bi_errorf("%s: %s", cp, lookup_msgs[ecode]);
return 1;
}
if (j->pgrp == 0) {
sigprocmask(SIG_SETMASK, &omask, NULL);
bi_errorf("job not job-controlled");
return 1;
}
if (bg)
shprintf("[%d] ", j->job);
running = 0;
for (p = j->proc_list; p != NULL; p = p->next) {
if (p->state == PSTOPPED) {
p->state = PRUNNING;
p->status = 0;
running = 1;
}
shprintf("%s%s", p->command, p->next ? "| " : "");
}
shprintf("\n");
shf_flush(shl_stdout);
if (running)
j->state = PRUNNING;
put_job(j, PJ_PAST_STOPPED);
if (bg)
j_set_async(j);
else {
/* attach tty to job */
if (j->state == PRUNNING) {
if (ttypgrp_ok && (j->flags & JF_SAVEDTTY))
tcsetattr(tty_fd, TCSADRAIN, &j->ttystate);
/* See comment in j_waitj regarding saved_ttypgrp. */
if (ttypgrp_ok &&
tcsetpgrp(tty_fd, (j->flags & JF_SAVEDTTYPGRP) ?
j->saved_ttypgrp : j->pgrp) == -1) {
if (j->flags & JF_SAVEDTTY)
tcsetattr(tty_fd, TCSADRAIN, &tty_state);
sigprocmask(SIG_SETMASK, &omask, NULL);
bi_errorf("1st tcsetpgrp(%d, %d) failed: %s",
tty_fd,
(int) ((j->flags & JF_SAVEDTTYPGRP) ?
j->saved_ttypgrp : j->pgrp),
strerror(errno));
return 1;
}
}
j->flags |= JF_FG;
j->flags &= ~JF_KNOWN;
if (j == async_job)
async_job = NULL;
}
if (j->state == PRUNNING && killpg(j->pgrp, SIGCONT) == -1) {
int err = errno;
if (!bg) {
j->flags &= ~JF_FG;
if (ttypgrp_ok && (j->flags & JF_SAVEDTTY))
tcsetattr(tty_fd, TCSADRAIN, &tty_state);
if (ttypgrp_ok && tcsetpgrp(tty_fd, our_pgrp) == -1) {
warningf(true,
"fg: 2nd tcsetpgrp(%d, %d) failed: %s",
tty_fd, (int) our_pgrp,
strerror(errno));
}
}
sigprocmask(SIG_SETMASK, &omask, NULL);
bi_errorf("cannot continue job %s: %s",
cp, strerror(err));
return 1;
}
if (!bg) {
if (ttypgrp_ok) {
j->flags &= ~(JF_SAVEDTTY | JF_SAVEDTTYPGRP);
}
rv = j_waitj(j, JW_NONE, "jw:resume");
}
sigprocmask(SIG_SETMASK, &omask, NULL);
return rv;
}
/* are there any running or stopped jobs ? */
int
j_stopped_running(void)
{
Job *j;
int which = 0;
for (j = job_list; j != NULL; j = j->next) {
if (j->ppid == procpid && j->state == PSTOPPED)
which |= 1;
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;
}
int
j_njobs(void)
{
Job *j;
int nj = 0;
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
for (j = job_list; j; j = j->next)
nj++;
sigprocmask(SIG_SETMASK, &omask, NULL);
return nj;
}
/* list jobs for jobs built-in */
int
j_jobs(const char *cp, int slp,
int nflag) /* 0: short, 1: long, 2: pgrp */
{
Job *j, *tmp;
int how;
int zflag = 0;
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
if (nflag < 0) { /* kludge: print zombies */
nflag = 0;
zflag = 1;
}
if (cp) {
int ecode;
if ((j = j_lookup(cp, &ecode)) == NULL) {
sigprocmask(SIG_SETMASK, &omask, NULL);
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");
}
sigprocmask(SIG_SETMASK, &omask, NULL);
return 0;
}
/* list jobs for top-level notification */
void
j_notify(void)
{
Job *j, *tmp;
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
for (j = job_list; j; j = j->next) {
if (Flag(FMONITOR) && (j->flags & JF_CHANGED))
j_print(j, JP_MEDIUM, shl_out);
/* 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);
sigprocmask(SIG_SETMASK, &omask, NULL);
}
/* Return pid of last process in last asynchronous job */
pid_t
j_async(void)
{
sigset_t omask;
sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
if (async_job)
async_job->flags |= JF_KNOWN;
sigprocmask(SIG_SETMASK, &omask, NULL);
return async_pid;
}
/* Make j the last async process
*
* Expects sigchld to be blocked.
*/
static void
j_set_async(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_warningf("%s: job not started", __func__);
return;
}
async_job = j;
async_pid = j->last_proc->pid;
while (nzombie > child_max) {
oldest = NULL;
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_warningf("%s: bad nzombie (%d)",
__func__, nzombie);
nzombie = 0;
}
break;
}
remove_job(oldest, "zombie");
}
}
/* Start a job: set STARTED, check for held signals and set j->last_proc
*
* Expects sigchld to be blocked.
*/
static void
j_startjob(Job *j)
{
Proc *p;
j->flags |= JF_STARTED;
for (p = j->proc_list; p->next; p = p->next)
;
j->last_proc = p;
if (held_sigchld) {
held_sigchld = 0;
/* Don't call j_sigchld() as it may remove job... */
kill(procpid, SIGCHLD);
}
}
/*
* wait for job to complete or change state
*
* Expects sigchld to be blocked.
*/
static int
j_waitj(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)) {
sigsuspend(&sm_default);
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) {
int status;
j->flags &= ~JF_FG;
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 foregrounded 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) == -1) {
warningf(true,
"%s: tcsetpgrp(%d, %d) failed: %s",
__func__, tty_fd, (int)our_pgrp,
strerror(errno));
}
if (j->state == PSTOPPED) {
j->flags |= JF_SAVEDTTY;
tcgetattr(tty_fd, &j->ttystate);
}
}
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)) {
tcgetattr(tty_fd, &tty_state);
} else {
tcsetattr(tty_fd, TCSADRAIN, &tty_state);
/* Don't use tty mode if job is stopped and
* later restarted and exits. Consider
* the sequence:
* vi foo (stopped)
* ...
* stty something
* ...
* fg (vi; ZZ)
* mode should be that of the stty, not what
* was before the vi started.
*/
if (j->state == PSTOPPED)
j->flags &= ~JF_USETTYMODE;
}
}
/* If it looks like user hit ^C to kill a job, pretend we got
* one too to break out of for loops, etc. (at&t ksh does this
* even when not monitoring, but this doesn't make sense since
* a tty generated ^C goes to the whole process group)
*/
status = j->last_proc->status;
if (Flag(FMONITOR) && j->state == PSIGNALLED &&
WIFSIGNALED(status) &&
(sigtraps[WTERMSIG(status)].flags & TF_TTY_INTR))
trapsig(WTERMSIG(status));
}
j_usrtime = j->usrtime;
j_systime = j->systime;
if (j->flags & JF_PIPEFAIL) {
Proc *p;
int status;
rv = 0;
for (p = j->proc_list; p != NULL; p = p->next) {
switch (p->state) {
case PEXITED:
status = WEXITSTATUS(p->status);
break;
case PSIGNALLED:
status = 128 + WTERMSIG(p->status);
break;
default:
status = 0;
break;
}
if (status)
rv = status;
}
} else
rv = j->status;
if (!(flags & JW_ASYNCNOTIFY) &&
(!Flag(FMONITOR) || j->state != PSTOPPED)) {
j_print(j, JP_SHORT, shl_out);
shf_flush(shl_out);
}
if (j->state != PSTOPPED &&
(!Flag(FMONITOR) || !(flags & JW_ASYNCNOTIFY)))
remove_job(j, where);
return rv;
}
/* SIGCHLD handler to reap children and update job states
*
* Expects sigchld to be blocked.
*/
static void
j_sigchld(int sig)
{
int errno_ = errno;
Job *j;
Proc *p = NULL;
int pid;
int status;
struct rusage ru0, ru1;
/* Don't wait for any processes if a job is partially started.
* This is so we don't do away with the process group leader
* before all the processes in a pipe line are started (so the
* setpgid() won't fail)
*/
for (j = job_list; j; j = j->next)
if (j->ppid == procpid && !(j->flags & JF_STARTED)) {
held_sigchld = 1;
goto finished;
}
getrusage(RUSAGE_CHILDREN, &ru0);
do {
pid = waitpid(-1, &status, (WNOHANG|WUNTRACED));
if (pid <= 0) /* return if would block (0) ... */
break; /* ... or no children or interrupted (-1) */
getrusage(RUSAGE_CHILDREN, &ru1);
/* find job and process structures for this pid */
for (j = job_list; j != NULL; j = j->next)
for (p = j->proc_list; p != NULL; p = p->next)
if (p->pid == pid)
goto found;
found:
if (j == NULL) {
/* Can occur if process has kids, then execs shell
warningf(true, "bad process waited for (pid = %d)",
pid);
*/
ru0 = ru1;
continue;
}
timeradd(&j->usrtime, &ru1.ru_utime, &j->usrtime);
timersub(&j->usrtime, &ru0.ru_utime, &j->usrtime);
timeradd(&j->systime, &ru1.ru_stime, &j->systime);
timersub(&j->systime, &ru0.ru_stime, &j->systime);
ru0 = ru1;
p->status = status;
if (WIFSTOPPED(status))
p->state = PSTOPPED;
else if (WIFSIGNALED(status))
p->state = PSIGNALLED;
else
p->state = PEXITED;
check_job(j); /* check to see if entire job is done */
} while (1);
finished:
errno = errno_;
}
/*
* Called only when a process in j has exited/stopped (ie, called only
* from j_sigchld()). If no processes are running, the job status
* and state are updated, asynchronous job notification is done and,
* if unneeded, the job is removed.
*
* Expects sigchld to be blocked.
*/
static void
check_job(Job *j)
{
int jstate;
Proc *p;
/* XXX debugging (nasty - interrupt routine using shl_out) */
if (!(j->flags & JF_STARTED)) {
internal_warningf("%s: job started (flags 0x%x)",
__func__, j->flags);
return;
}
jstate = PRUNNING;
for (p=j->proc_list; p != NULL; p = p->next) {
if (p->state == PRUNNING)
return; /* some processes still running */
if (p->state > jstate)
jstate = p->state;
}
j->state = jstate;
switch (j->last_proc->state) {
case PEXITED:
j->status = WEXITSTATUS(j->last_proc->status);
break;
case PSIGNALLED:
j->status = 128 + WTERMSIG(j->last_proc->status);
break;
default:
j->status = 0;
break;
}
/* Note when co-process dies: can't be done in j_wait() nor
* remove_job() since neither may be called for non-interactive
* shells.
*/
if (j->state == PEXITED || j->state == PSIGNALLED) {
/* No need to keep co-process input any more
* (at least, this is what ksh93d thinks)
*/
if (coproc.job == j) {
coproc.job = NULL;
/* XXX would be nice to get the closes out of here
* so they aren't done in the signal handler.
* Would mean a check in coproc_getfd() to
* do "if job == 0 && write >= 0, close write".
*/
coproc_write_close(coproc.write);
}
/* Do we need to keep the output? */
if (j->coproc_id && j->coproc_id == coproc.id &&
--coproc.njobs == 0)
coproc_readw_close(coproc.read);
}
j->flags |= JF_CHANGED;
if (Flag(FMONITOR) && !(j->flags & JF_XXCOM)) {
/* Only put stopped jobs at the front to avoid confusing
* the user (don't want finished jobs effecting %+ or %-)
*/
if (j->state == PSTOPPED)
put_job(j, PJ_ON_FRONT);
if (Flag(FNOTIFY) &&
(j->flags & (JF_WAITING|JF_W_ASYNCNOTIFY)) != JF_WAITING) {
/* Look for the real file descriptor 2 */
{
struct env *ep;
int fd = 2;
for (ep = genv; ep; ep = ep->oenv)
if (ep->savefd && ep->savefd[2])
fd = ep->savefd[2];
shf_reopen(fd, SHF_WR, shl_j);
}
/* Can't call j_notify() as it removes jobs. The job
* must stay in the job list as j_waitj() may be
* running with this job.
*/
j_print(j, JP_MEDIUM, shl_j);
shf_flush(shl_j);
if (!(j->flags & JF_WAITING) && j->state != PSTOPPED)
remove_job(j, "notify");
}
}
if (!Flag(FMONITOR) && !(j->flags & (JF_WAITING|JF_FG)) &&
j->state != PSTOPPED) {
if (j == async_job || (j->flags & JF_KNOWN)) {
j->flags |= JF_ZOMBIE;
j->job = -1;
nzombie++;
} else
remove_job(j, "checkjob");
}
}
/*
* Print job status in either short, medium or long format.
*
* Expects sigchld to be blocked.
*/
static void
j_print(Job *j, int how, struct shf *shf)
{
Proc *p;
int state;
int status;
int coredumped;
char jobchar = ' ';
char buf[64];
const char *filler;
int output = 0;
if (how == JP_PGRP) {
/* POSIX doesn't say what to do if there is no process
* group leader (ie, !FMONITOR). We arbitrarily return
* last pid (which is what $! returns).
*/
shf_fprintf(shf, "%d\n", j->pgrp ? j->pgrp :
(j->last_proc ? j->last_proc->pid : 0));
return;
}
j->flags &= ~JF_CHANGED;
filler = j->job > 10 ? "\n " : "\n ";
if (j == job_list)
jobchar = '+';
else if (j == job_list->next)
jobchar = '-';
for (p = j->proc_list; p != NULL;) {
coredumped = 0;
switch (p->state) {
case PRUNNING:
strlcpy(buf, "Running", sizeof buf);
break;
case PSTOPPED:
strlcpy(buf, sigtraps[WSTOPSIG(p->status)].mess,
sizeof buf);
break;
case PEXITED:
if (how == JP_SHORT)
buf[0] = '\0';
else if (WEXITSTATUS(p->status) == 0)
strlcpy(buf, "Done", sizeof buf);
else
shf_snprintf(buf, sizeof(buf), "Done (%d)",
WEXITSTATUS(p->status));
break;
case PSIGNALLED:
if (WCOREDUMP(p->status))
coredumped = 1;
/* kludge for not reporting `normal termination signals'
* (ie, SIGINT, SIGPIPE)
*/
if (how == JP_SHORT && !coredumped &&
(WTERMSIG(p->status) == SIGINT ||
WTERMSIG(p->status) == SIGPIPE)) {
buf[0] = '\0';
} else
strlcpy(buf, sigtraps[WTERMSIG(p->status)].mess,
sizeof buf);
break;
}
if (how != JP_SHORT) {
if (p == j->proc_list)
shf_fprintf(shf, "[%d] %c ", j->job, jobchar);
else
shf_fprintf(shf, "%s", filler);
}
if (how == JP_LONG)
shf_fprintf(shf, "%5d ", p->pid);
if (how == JP_SHORT) {
if (buf[0]) {
output = 1;
shf_fprintf(shf, "%s%s ",
buf, coredumped ? " (core dumped)" : "");
}
} else {
output = 1;
shf_fprintf(shf, "%-20s %s%s%s", buf, p->command,
p->next ? "|" : "",
coredumped ? " (core dumped)" : "");
}
state = p->state;
status = p->status;
p = p->next;
while (p && p->state == state && p->status == status) {
if (how == JP_LONG)
shf_fprintf(shf, "%s%5d %-20s %s%s", filler, p->pid,
" ", p->command, p->next ? "|" : "");
else if (how == JP_MEDIUM)
shf_fprintf(shf, " %s%s", p->command,
p->next ? "|" : "");
p = p->next;
}
}
if (output)
shf_fprintf(shf, "\n");
}
/* Convert % sequence to job
*
* Expects sigchld to be blocked.
*/
static Job *
j_lookup(const char *cp, int *ecodep)
{
Job *j, *last_match;
const char *errstr;
Proc *p;
int len, job = 0;
if (digit(*cp)) {
job = strtonum(cp, 1, INT_MAX, &errstr);
if (errstr) {
if (ecodep)
*ecodep = JL_NOSUCH;
return NULL;
}
/* Look for last_proc->pid (what $! returns) first... */
for (j = job_list; j != NULL; j = j->next)
if (j->last_proc && j->last_proc->pid == job)
return j;
/* ...then look for process group (this is non-POSIX),
* but should not break anything (so FPOSIX isn't used).
*/
for (j = job_list; j != NULL; j = j->next)
if (j->pgrp && j->pgrp == job)
return j;
if (ecodep)
*ecodep = JL_NOSUCH;
return NULL;
}
if (*cp != '%') {
if (ecodep)
*ecodep = JL_INVALID;
return NULL;
}
switch (*++cp) {
case '\0': /* non-standard */
case '+':
case '%':
if (job_list != NULL)
return job_list;
break;
case '-':
if (job_list != NULL && job_list->next)
return job_list->next;
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
job = strtonum(cp, 1, INT_MAX, &errstr);
if (errstr)
break;
for (j = job_list; j != NULL; j = j->next)
if (j->job == job)
return j;
break;
case '?': /* %?string */
last_match = NULL;
for (j = job_list; j != NULL; j = j->next)
for (p = j->proc_list; p != NULL; p = p->next)
if (strstr(p->command, cp+1) != NULL) {
if (last_match) {
if (ecodep)
*ecodep = JL_AMBIG;
return NULL;
}
last_match = j;
}
if (last_match)
return last_match;
break;
default: /* %string */
len = strlen(cp);
last_match = NULL;
for (j = job_list; j != NULL; j = j->next)
if (strncmp(cp, j->proc_list->command, len) == 0) {
if (last_match) {
if (ecodep)
*ecodep = JL_AMBIG;
return NULL;
}
last_match = j;
}
if (last_match)
return last_match;
break;
}
if (ecodep)
*ecodep = JL_NOSUCH;
return NULL;
}
static Job *free_jobs;
static Proc *free_procs;
/* allocate a new job and fill in the job number.
*
* Expects sigchld to be blocked.
*/
static Job *
new_job(void)
{
int i;
Job *newj, *j;
if (free_jobs != NULL) {
newj = free_jobs;
free_jobs = free_jobs->next;
} else
newj = alloc(sizeof(Job), APERM);
/* brute force method */
for (i = 1; ; i++) {
for (j = job_list; j && j->job != i; j = j->next)
;
if (j == NULL)
break;
}
newj->job = i;
return newj;
}
/* Allocate new process struct
*
* Expects sigchld to be blocked.
*/
static Proc *
new_proc(void)
{
Proc *p;
if (free_procs != NULL) {
p = free_procs;
free_procs = free_procs->next;
} else
p = alloc(sizeof(Proc), APERM);
return p;
}
/* Take job out of job_list and put old structures into free list.
* Keeps nzombies, last_job and async_job up to date.
*
* Expects sigchld to be blocked.
*/
static void
remove_job(Job *j, const char *where)
{
Proc *p, *tmp;
Job **prev, *curr;
prev = &job_list;
curr = *prev;
for (; curr != NULL && curr != j; prev = &curr->next, curr = *prev)
;
if (curr != j) {
internal_warningf("%s: job not found (%s)", __func__, where);
return;
}
*prev = curr->next;
/* free up proc structures */
for (p = j->proc_list; p != NULL; ) {
tmp = p;
p = p->next;
tmp->next = free_procs;
free_procs = tmp;
}
if ((j->flags & JF_ZOMBIE) && j->ppid == procpid)
--nzombie;
j->next = free_jobs;
free_jobs = j;
if (j == last_job)
last_job = NULL;
if (j == async_job)
async_job = NULL;
}
/* Put j in a particular location (taking it out of job_list if it is
* there already)
*
* Expects sigchld to be blocked.
*/
static void
put_job(Job *j, int where)
{
Job **prev, *curr;
/* Remove job from list (if there) */
prev = &job_list;
curr = job_list;
for (; curr && curr != j; prev = &curr->next, curr = *prev)
;
if (curr == j)
*prev = curr->next;
switch (where) {
case PJ_ON_FRONT:
j->next = job_list;
job_list = j;
break;
case PJ_PAST_STOPPED:
prev = &job_list;
curr = job_list;
for (; curr && curr->state == PSTOPPED; prev = &curr->next,
curr = *prev)
;
j->next = curr;
*prev = j;
break;
}
}
/* nuke a job (called when unable to start full job).
*
* Expects sigchld to be blocked.
*/
static int
kill_job(Job *j, int sig)
{
Proc *p;
int rval = 0;
for (p = j->proc_list; p != NULL; p = p->next)
if (p->pid != 0)
if (kill(p->pid, sig) == -1)
rval = -1;
return rval;
}
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