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groff-1.08
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pipeline.c
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1992-08-08
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/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
Written by James Clark (jjc@jclark.com)
This file is part of groff.
groff is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
groff is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
with groff; see the file COPYING. If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/*
Compile options are:
-DWCOREFLAG=0200 (or whatever)
-DHAVE_VFORK_H
-Dvfork=fork
-DHAVE_SYS_SIGLIST
-DHAVE_UNISTD_H
*/
#include <stdio.h>
#include <signal.h>
#include <errno.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_VFORK_H
#include <vfork.h>
#endif
#ifndef errno
extern int errno;
#endif
extern char *strerror();
#ifdef _POSIX_VERSION
#include <sys/wait.h>
#define PID_T pid_t
#else /* not _POSIX_VERSION */
/* traditional Unix */
#define WIFEXITED(s) (((s) & 0377) == 0)
#define WIFSTOPPED(s) (((s) & 0377) == 0177)
#define WIFSIGNALED(s) (((s) & 0377) != 0 && (((s) & 0377) != 0177))
#define WEXITSTATUS(s) (((s) >> 8) & 0377)
#define WTERMSIG(s) ((s) & 0177)
#define WSTOPSIG(s) (((s) >> 8) & 0377)
#ifndef WCOREFLAG
#define WCOREFLAG 0200
#endif
#define PID_T int
#endif /* not _POSIX_VERSION */
/* SVR4 uses WCOREFLG; Net 2 uses WCOREFLAG. */
#ifndef WCOREFLAG
#ifdef WCOREFLG
#define WCOREFLAG WCOREFLG
#endif /* WCOREFLG */
#endif /* not WCOREFLAG */
#ifndef WCOREDUMP
#ifdef WCOREFLAG
#define WCOREDUMP(s) ((s) & WCOREFLAG)
#else /* not WCOREFLAG */
#define WCOREDUMP(s) (0)
#endif /* WCOREFLAG */
#endif /* not WCOREDUMP */
#include "pipeline.h"
#ifdef __STDC__
#define P(parms) parms
#else
#define P(parms) ()
#endif
#define error c_error
extern void error P((char *, char *, char *, char *));
static void sys_fatal P((char *));
static char *strsignal P((int));
static char *itoa P((int));
int run_pipeline(ncommands, commands)
int ncommands;
char ***commands;
{
int i;
int last_input = 0;
PID_T pids[MAX_COMMANDS];
int ret = 0;
int proc_count = ncommands;
for (i = 0; i < ncommands; i++) {
int pdes[2];
PID_T pid;
if (i != ncommands - 1) {
if (pipe(pdes) < 0)
sys_fatal("pipe");
}
pid = vfork();
if (pid < 0)
sys_fatal("fork");
if (pid == 0) {
/* child */
if (last_input != 0) {
if (close(0) < 0)
sys_fatal("close");
if (dup(last_input) < 0)
sys_fatal("dup");
if (close(last_input) < 0)
sys_fatal("close");
}
if (i != ncommands - 1) {
if (close(1) < 0)
sys_fatal("close");
if (dup(pdes[1]) < 0)
sys_fatal("dup");
if (close(pdes[1]) < 0)
sys_fatal("close");
if (close(pdes[0]))
sys_fatal("close");
}
execvp(commands[i][0], commands[i]);
error("couldn't exec %1: %2", commands[i][0],
strerror(errno), (char *)0);
fflush(stderr); /* just in case error() doesn't */
_exit(EXEC_FAILED_EXIT_STATUS);
}
/* in the parent */
if (last_input != 0) {
if (close(last_input) < 0)
sys_fatal("close");
}
if (i != ncommands - 1) {
if (close(pdes[1]) < 0)
sys_fatal("close");
last_input = pdes[0];
}
pids[i] = pid;
}
while (proc_count > 0) {
int status;
PID_T pid = wait(&status);
if (pid < 0)
sys_fatal("wait");
for (i = 0; i < ncommands; i++)
if (pids[i] == pid) {
pids[i] = -1;
--proc_count;
if (WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
#ifdef SIGPIPE
if (sig == SIGPIPE) {
if (i == ncommands - 1) {
/* This works around a problem that occurred when using the
rerasterize action in gxditview. What seemed to be
happening (on SunOS 4.1.1) was that pclose() closed the
pipe and waited for groff, gtroff got a SIGPIPE, but
gpic blocked writing to gtroff, and so groff blocked
waiting for gpic and gxditview blocked waiting for
groff. I don't understand why gpic wasn't getting a
SIGPIPE. */
int j;
for (j = 0; j < ncommands; j++)
if (pids[j] > 0)
(void)kill(pids[j], SIGPIPE);
}
}
else
#endif /* SIGPIPE */
{
error("%1: %2%3",
commands[i][0],
strsignal(sig),
WCOREDUMP(status) ? " (core dumped)" : "");
ret |= 2;
}
}
else if (WIFEXITED(status)) {
int exit_status = WEXITSTATUS(status);
if (exit_status == EXEC_FAILED_EXIT_STATUS)
ret |= 4;
else if (exit_status != 0)
ret |= 1;
}
else
error("unexpected status %1",
itoa(status), (char *)0, (char *)0);
break;
}
}
return ret;
}
static void sys_fatal(s)
char *s;
{
c_fatal("%1: %2", s, strerror(errno), (char *)0);
}
static char *itoa(n)
int n;
{
static char buf[12];
sprintf(buf, "%d", n);
return buf;
}
static char *strsignal(n)
int n;
{
static char buf[sizeof("Signal ") + 1 + sizeof(int)*3];
#ifdef HAVE_SYS_SIGLIST
extern char *sys_siglist[];
if (n >= 0 && n < NSIG && sys_siglist[n] != 0)
return sys_siglist[n];
#endif /* HAVE_SYS_SIGLIST */
sprintf(buf, "Signal %d", n);
return buf;
}