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/**
@file
@ingroup util
@brief Forks a command and sets up pipes to and from.
@author Rick L Spickelmier
@author Richard Rudell
@copyright@parblock
Copyright (c) 1994-1998 The Regents of the Univ. of California.
All rights reserved.
Permission is hereby granted, without written agreement and without license
or royalty fees, to use, copy, modify, and distribute this software and its
documentation for any purpose, provided that the above copyright notice and
the following two paragraphs appear in all copies of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN
"AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO PROVIDE
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
@endparblock
@copyright@parblock
Copyright (c) 1999-2015, Regents of the University of Colorado
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
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.
Neither the name of the University of Colorado 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 COPYRIGHT HOLDERS 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
COPYRIGHT OWNER 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.
@endparblock
*/
#include "config.h"
#if HAVE_UNISTD_H == 1
#define _POSIX_SOURCE
#include <unistd.h>
#endif
#include <stdio.h>
#if HAVE_SYS_WAIT_H == 1
#include <sys/wait.h>
#endif
/**
* @def EXTERN
* @brief Allows C linkage when compiling as C++.
*/
#ifndef EXTERN
# ifdef __cplusplus
# define EXTERN extern "C"
# else
# define EXTERN extern
# endif
#endif
/**
* @brief Forks a command and sets up pipes to and from.
*
* @return 1 for success, with toCommand and fromCommand pointing to
* the streams; 0 for failure
*/
int
util_pipefork(
char * const *argv, /**< normal argv argument list */
FILE **toCommand, /**< pointer to the sending stream */
FILE **fromCommand, /**< pointer to the reading stream */
int *pid /**< process ID */)
{
#if HAVE_SYS_WAIT_H == 1
int forkpid, waitPid;
int topipe[2], frompipe[2];
char buffer[1024];
int status;
/* create the PIPES...
* fildes[0] for reading from command
* fildes[1] for writing to command
*/
if (pipe(topipe)) return(0);
if (pipe(frompipe)) return(0);
if ((forkpid = fork()) == 0) {
/* child here, connect the pipes */
(void) dup2(topipe[0], fileno(stdin));
(void) dup2(frompipe[1], fileno(stdout));
(void) close(topipe[0]);
(void) close(topipe[1]);
(void) close(frompipe[0]);
(void) close(frompipe[1]);
(void) execvp(argv[0], argv);
(void) sprintf(buffer, "util_pipefork: can not exec %s", argv[0]);
perror(buffer);
(void) _exit(1);
}
if (pid) {
*pid = forkpid;
}
waitPid = waitpid(-1, &status, WNOHANG);
/* parent here, use fork() semantics to get return status */
if (waitPid == forkpid && WIFEXITED(status)) {
return 0;
}
if ((*toCommand = fdopen(topipe[1], "w")) == NULL) {
return 0;
}
if ((*fromCommand = fdopen(frompipe[0], "r")) == NULL) {
return 0;
}
(void) close(topipe[0]);
(void) close(frompipe[1]);
return 1;
#else
(void) argv; /* to avoid warning */
(void) toCommand; /* to avoid warning */
(void) fromCommand; /* to avoid warning */
(void) pid; /* to avoid warning */
(void) fprintf(stderr,
"util_pipefork: not implemented on your operating system\n");
return 0;
#endif
}