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/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software written by Ken Arnold and
* published in UNIX Review, Vol. 6, No. 8.
*
* 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.
* 4. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 5/3/95";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/wait.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
#include <pthread.h>
#include "un-namespace.h"
#include "libc_private.h"
extern char **environ;
struct pid {
SLIST_ENTRY(pid) next;
FILE *fp;
pid_t pid;
};
static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist);
static pthread_mutex_t pidlist_mutex = PTHREAD_MUTEX_INITIALIZER;
#define THREAD_LOCK() if (__isthreaded) _pthread_mutex_lock(&pidlist_mutex)
#define THREAD_UNLOCK() if (__isthreaded) _pthread_mutex_unlock(&pidlist_mutex)
FILE *
popen(command, type)
const char *command, *type;
{
struct pid *cur;
FILE *iop;
int pdes[2], pid, twoway;
char *argv[4];
struct pid *p;
/*
* Lite2 introduced two-way popen() pipes using _socketpair().
* FreeBSD's pipe() is bidirectional, so we use that.
*/
if (strchr(type, '+')) {
twoway = 1;
type = "r+";
} else {
twoway = 0;
if ((*type != 'r' && *type != 'w') || type[1])
return (NULL);
}
if (pipe(pdes) < 0)
return (NULL);
if ((cur = malloc(sizeof(struct pid))) == NULL) {
(void)_close(pdes[0]);
(void)_close(pdes[1]);
return (NULL);
}
argv[0] = "sh";
argv[1] = "-c";
argv[2] = (char *)command;
argv[3] = NULL;
THREAD_LOCK();
switch (pid = vfork()) {
case -1: /* Error. */
THREAD_UNLOCK();
(void)_close(pdes[0]);
(void)_close(pdes[1]);
free(cur);
return (NULL);
/* NOTREACHED */
case 0: /* Child. */
if (*type == 'r') {
/*
* The _dup2() to STDIN_FILENO is repeated to avoid
* writing to pdes[1], which might corrupt the
* parent's copy. This isn't good enough in
* general, since the _exit() is no return, so
* the compiler is free to corrupt all the local
* variables.
*/
(void)_close(pdes[0]);
if (pdes[1] != STDOUT_FILENO) {
(void)_dup2(pdes[1], STDOUT_FILENO);
(void)_close(pdes[1]);
if (twoway)
(void)_dup2(STDOUT_FILENO, STDIN_FILENO);
} else if (twoway && (pdes[1] != STDIN_FILENO))
(void)_dup2(pdes[1], STDIN_FILENO);
} else {
if (pdes[0] != STDIN_FILENO) {
(void)_dup2(pdes[0], STDIN_FILENO);
(void)_close(pdes[0]);
}
(void)_close(pdes[1]);
}
SLIST_FOREACH(p, &pidlist, next)
(void)_close(fileno(p->fp));
_execve(_PATH_BSHELL, argv, environ);
_exit(127);
/* NOTREACHED */
}
THREAD_UNLOCK();
/* Parent; assume fdopen can't fail. */
if (*type == 'r') {
iop = fdopen(pdes[0], type);
(void)_close(pdes[1]);
} else {
iop = fdopen(pdes[1], type);
(void)_close(pdes[0]);
}
/* Link into list of file descriptors. */
cur->fp = iop;
cur->pid = pid;
THREAD_LOCK();
SLIST_INSERT_HEAD(&pidlist, cur, next);
THREAD_UNLOCK();
return (iop);
}
/*
* pclose --
* Pclose returns -1 if stream is not associated with a `popened' command,
* if already `pclosed', or waitpid returns an error.
*/
int
pclose(iop)
FILE *iop;
{
struct pid *cur, *last = NULL;
int pstat;
pid_t pid;
/*
* Find the appropriate file pointer and remove it from the list.
*/
THREAD_LOCK();
SLIST_FOREACH(cur, &pidlist, next) {
if (cur->fp == iop)
break;
last = cur;
}
if (cur == NULL) {
THREAD_UNLOCK();
return (-1);
}
if (last == NULL)
SLIST_REMOVE_HEAD(&pidlist, next);
else
SLIST_REMOVE_AFTER(last, next);
THREAD_UNLOCK();
(void)fclose(iop);
do {
pid = _wait4(cur->pid, &pstat, 0, (struct rusage *)0);
} while (pid == -1 && errno == EINTR);
free(cur);
return (pid == -1 ? -1 : pstat);
}
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