/* $NetBSD: jobs.c,v 1.62 2003/12/18 00:56:05 christos 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 #ifndef lint #if 0 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; #else __RCSID("$NetBSD: jobs.c,v 1.62 2003/12/18 00:56:05 christos Exp $"); #endif #endif /* not lint */ #include #include #include #include #include #include #include #include #ifdef BSD #include #include #include #endif #include #include "shell.h" #if JOBS #if OLD_TTY_DRIVER #include "sgtty.h" #else #include #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 "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 static int ttyfd = -1; STATIC void restartjob(struct job *); STATIC void freejob(struct job *); STATIC struct job *getjob(const char *, int); STATIC int dowait(int, struct job *); STATIC int onsigchild(void); STATIC int waitproc(int, struct job *, int *); STATIC void cmdtxt(union node *); STATIC void cmdlist(union node *, int); STATIC void cmdputs(const char *); #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; 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 (getpgid(0) != 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 (getpgid(0) != 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; } #ifdef mkinit INCLUDE SHELLPROC { backgndpid = -1; #if JOBS jobctl = 0; #endif } #endif #if JOBS int fgcmd(int argc, char **argv) { struct job *jp; int i; int status; nextopt(""); jp = getjob(*argptr, 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; } 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; } #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; #ifdef JOBS /* * Check if we are not in our foreground group, and if not * put us in it. */ if (mflag && gotpid != -1 && tcgetpgrp(ttyfd) != getpid()) { if (tcsetpgrp(ttyfd, getpid()) == -1) error("Cannot set tty process group (%s) at %d", strerror(errno), __LINE__); TRACE(("repaired tty process group\n")); silent = 1; } #endif if (jobs_invalid) return; for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { if (!jp->used) continue; if (jp->nprocs == 0) { freejob(jp); continue; } if ((mode & SHOW_CHANGED) && !jp->changed) continue; if (silent && jp->changed) { jp->changed = 0; continue; } showjob(out, jp, mode); } } /* * Mark a job structure as unused. */ STATIC void freejob(struct job *jp) { INTOFF; if (jp->ps != &jp->ps0) { ckfree(jp->ps); jp->ps = &jp->ps0; } jp->nprocs = 0; jp->used = 0; #if JOBS set_curjob(jp, 0); #endif INTON; } int waitcmd(int argc, char **argv) { struct job *job; int status, retval; struct job *jp; nextopt(""); if (!*argptr) { /* wait for all jobs */ jp = jobtab; if (jobs_invalid) return 0; for (;;) { if (jp >= jobtab + njobs) { /* no running procs */ return 0; } if (!jp->used || jp->state != JOBRUNNING) { jp++; continue; } if (dowait(1, (struct job *)NULL) == -1) return 128 + SIGINT; jp = jobtab; } } for (; *argptr; argptr++) { job = getjob(*argptr, 1); if (!job) { retval = 127; continue; } /* loop until process terminated or stopped */ while (job->state == JOBRUNNING) { if (dowait(1, (struct job *)NULL) == -1) return 128 + SIGINT; } status = job->ps[job->nprocs].status; if (WIFEXITED(status)) retval = WEXITSTATUS(status); #if JOBS else if (WIFSTOPPED(status)) retval = WSTOPSIG(status) + 128; #endif else { /* XXX: limits number of signals */ retval = WTERMSIG(status) + 128; } if (!iflag) freejob(job); } return retval; } int jobidcmd(int argc, char **argv) { struct job *jp; int i; nextopt(""); jp = getjob(*argptr, 0); for (i = 0 ; i < jp->nprocs ; ) { out1fmt("%ld", (long)jp->ps[i].pid); out1c(++i < jp->nprocs ? ' ' : '\n'); } return 0; } int getjobpgrp(const char *name) { struct job *jp; jp = getjob(name, 1); if (jp == 0) return 0; return -jp->ps[0].pid; } /* * Convert a job name to a job structure. */ STATIC struct job * getjob(const char *name, int noerror) { int jobno = -1; struct job *jp; int pid; int i; const char *err_msg = "No such job: %s"; if (name == NULL) { #if JOBS jobno = curjob; #endif err_msg = "No current job"; } else if (name[0] == '%') { if (is_number(name + 1)) { jobno = number(name + 1) - 1; } else if (!name[2]) { switch (name[1]) { #if JOBS case 0: case '+': case '%': jobno = curjob; err_msg = "No current job"; break; case '-': jobno = curjob; if (jobno != -1) jobno = jobtab[jobno].prev_job; err_msg = "No previous job"; break; #endif default: goto check_pattern; } } else { struct job *found; check_pattern: found = NULL; for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { if (!jp->used || jp->nprocs <= 0) continue; if ((name[1] == '?' && strstr(jp->ps[0].cmd, name + 2)) || prefix(name + 1, jp->ps[0].cmd)) { if (found) { err_msg = "%s: ambiguous"; found = 0; break; } found = jp; } } if (found) return found; } } else if (is_number(name)) { pid = number(name); for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { if (jp->used && jp->nprocs > 0 && jp->ps[jp->nprocs - 1].pid == pid) return jp; } } if (!jobs_invalid && jobno >= 0 && jobno < njobs) { jp = jobtab + jobno; if (jp->used) return jp; } if (!noerror) error(err_msg, name); return 0; } /* * Return a new job structure, */ struct job * makejob(union node *node, int nprocs) { int i; struct job *jp; if (jobs_invalid) { for (i = njobs, jp = jobtab ; --i >= 0 ; jp++) { if (jp->used) freejob(jp); } jobs_invalid = 0; } for (i = njobs, jp = jobtab ; ; jp++) { if (--i < 0) { INTOFF; if (njobs == 0) { jobtab = ckmalloc(4 * sizeof jobtab[0]); } else { jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); memcpy(jp, jobtab, njobs * sizeof jp[0]); /* Relocate `ps' pointers */ for (i = 0; i < njobs; i++) if (jp[i].ps == &jobtab[i].ps0) jp[i].ps = &jp[i].ps0; ckfree(jobtab); jobtab = jp; } jp = jobtab + njobs; for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); INTON; break; } if (jp->used == 0) break; } INTOFF; jp->state = JOBRUNNING; jp->used = 1; jp->changed = 0; jp->nprocs = 0; #if JOBS jp->jobctl = jobctl; set_curjob(jp, 1); #endif if (nprocs > 1) { jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); } else { jp->ps = &jp->ps0; } INTON; TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, jp - jobtab + 1)); return jp; } /* * Fork off a subshell. If we are doing job control, give the subshell its * own process group. Jp is a job structure that the job is to be added to. * N is the command that will be evaluated by the child. Both jp and n may * be NULL. The mode parameter can be one of the following: * FORK_FG - Fork off a foreground process. * FORK_BG - Fork off a background process. * FORK_NOJOB - Like FORK_FG, but don't give the process its own * process group even if job control is on. * * When job control is turned off, background processes have their standard * input redirected to /dev/null (except for the second and later processes * in a pipeline). */ int forkshell(struct job *jp, union node *n, int mode) { int pid; TRACE(("forkshell(%%%d, %p, %d) called\n", jp - jobtab, n, mode)); switch ((pid = fork())) { case -1: TRACE(("Fork failed, errno=%d\n", errno)); INTON; error("Cannot fork"); break; case 0: forkchild(jp, n, mode, 0); return 0; default: return forkparent(jp, n, mode, pid); } } int forkparent(struct job *jp, union node *n, int mode, pid_t pid) { int pgrp; if (rootshell && mode != FORK_NOJOB && mflag) { if (jp == NULL || jp->nprocs == 0) pgrp = pid; else pgrp = jp->ps[0].pid; /* This can fail because we are doing it in the child also */ (void)setpgid(pid, pgrp); } if (mode == FORK_BG) backgndpid = pid; /* set $! */ if (jp) { struct procstat *ps = &jp->ps[jp->nprocs++]; ps->pid = pid; ps->status = -1; ps->cmd[0] = 0; if (/* iflag && rootshell && */ n) commandtext(ps, n); } TRACE(("In parent shell: child = %d\n", pid)); return pid; } void forkchild(struct job *jp, union node *n, int mode, int vforked) { int wasroot; int pgrp; const char *devnull = _PATH_DEVNULL; const char *nullerr = "Can't open %s"; wasroot = rootshell; TRACE(("Child shell %d\n", getpid())); if (!vforked) rootshell = 0; closescript(vforked); clear_traps(vforked); #if JOBS if (!vforked) jobctl = 0; /* do job control only in root shell */ if (wasroot && mode != FORK_NOJOB && mflag) { if (jp == NULL || jp->nprocs == 0) pgrp = getpid(); else pgrp = jp->ps[0].pid; /* 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(1, 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 block, 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(%d) called\n", block)); do { pid = waitproc(block, 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) 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 it's * 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 wait3(status, flags, (struct rusage *)NULL); #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; }