popenvp.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*LINTLIBRARY*/
/*
* These routines are based on the standard UNIX stdio popen/pclose
* routines. This version takes an argv[][] argument instead of a string
* to be passed to the shell. The routine execvp() is used to call the
* program, hence the name popenvp() and the argument types.
*
* This routine avoids an extra shell completely, along with not having
* to worry about quoting conventions in strings that have spaces,
* quotes, etc.
*/
#include "synonyms.h"
#include <sys/types.h>
#include <assert.h>
#include <string.h>
#include "libmail.h"
#include <sys/wait.h>
#include <stdio.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#define tst(a, b) (*mode == 'r'? (b) : (a))
#define RDR 0
#define WTR 1
#include <unistd.h>
static pid_t popen_pid[20];
/* Functions calling popenvp() should ensure 'file' is non-NULL */
FILE *
popenvp(char *file, char **argv, char *mode, int resetid)
{
int p[2];
int myside, yourside;
pid_t pid;
assert(file != NULL);
if (pipe(p) < 0)
return (NULL);
myside = tst(p[WTR], p[RDR]);
yourside = tst(p[RDR], p[WTR]);
if ((pid = fork()) == 0) {
/* myside and yourside reverse roles in child */
int stdio;
if (resetid) {
(void) setgid(getgid());
(void) setuid(getuid());
}
stdio = tst(0, 1);
(void) close(myside);
(void) close(stdio);
(void) fcntl(yourside, F_DUPFD, stdio);
(void) close(yourside);
(void) execvp(file, argv);
(void) fprintf(stderr, "exec of \"%s\" failed: %s\n",
file, strerror(errno));
(void) fflush(stderr);
_exit(1);
}
if (pid == (pid_t)-1)
return (NULL);
popen_pid[myside] = pid;
(void) close(yourside);
return (fdopen(myside, mode));
}
int
pclosevp(FILE *ptr)
{
int f;
pid_t r;
int status;
void (*hstat)(int), (*istat)(int), (*qstat)(int);
f = fileno(ptr);
(void) fclose(ptr);
istat = signal(SIGINT, SIG_IGN);
qstat = signal(SIGQUIT, SIG_IGN);
hstat = signal(SIGHUP, SIG_IGN);
do
r = wait(&status);
while (r != popen_pid[f] && r != (pid_t)-1);
if (r == (pid_t)-1)
status = -1;
(void) signal(SIGINT, istat);
(void) signal(SIGQUIT, qstat);
(void) signal(SIGHUP, hstat);
return (status);
}