[apple/libc.git] / gen / popen.c

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 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.
 */

#include <sys/param.h>
#include <sys/wait.h>
#include <sys/socket.h>

#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
#include <crt_externs.h>

#define environ *(_NSGetEnviron())

static struct pid {
	struct pid *next;
	FILE *fp;
	pid_t pid;
} *pidlist; 
	
FILE *
popen(command, type)
	const char *command, *type;
{
	struct pid *cur;
	FILE *iop;
	int pdes[2], pid, twoway;
	char *argv[4];
	struct pid *p;

	if (strchr(type, '+')) {
		twoway = 1;
		type = "r+";
                if (socketpair(AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
                        return (NULL);
	} 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;

	switch (pid = vfork()) {
	case -1:			/* Error. */
		(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]);
			}
		for (p = pidlist; p; p = p->next) {
			(void)close(fileno(p->fp));
		}
		execve(_PATH_BSHELL, argv, environ);
		_exit(127);
		/* NOTREACHED */
	}

	/* 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;
	cur->next = pidlist;
	pidlist = cur;

	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;
{
	register struct pid *cur, *last;
	int pstat;
	pid_t pid;

	/* Find the appropriate file pointer. */
	for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next)
		if (cur->fp == iop)
			break;
	if (cur == NULL)
		return (-1);

	(void)fclose(iop);

	do {
		pid = wait4(cur->pid, &pstat, 0, (struct rusage *)0);
	} while (pid == -1 && errno == EINTR);

	/* Remove the entry from the linked list. */
	if (last == NULL)
		pidlist = cur->next;
	else
		last->next = cur->next;
	free(cur);
		
	return (pid == -1 ? -1 : pstat);
}
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
734aad71 A	5	*
	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
	7	*
	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
e9ce8d39 A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
e9ce8d39 A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
734aad71 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
	22	*
e9ce8d39 A	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1988, 1993
	27	* The Regents of the University of California. All rights reserved.
	28	*
	29	* This code is derived from software written by Ken Arnold and
	30	* published in UNIX Review, Vol. 6, No. 8.
	31	*
	32	* Redistribution and use in source and binary forms, with or without
	33	* modification, are permitted provided that the following conditions
	34	* are met:
	35	* 1. Redistributions of source code must retain the above copyright
	36	* notice, this list of conditions and the following disclaimer.
	37	* 2. Redistributions in binary form must reproduce the above copyright
	38	* notice, this list of conditions and the following disclaimer in the
	39	* documentation and/or other materials provided with the distribution.
	40	* 3. All advertising materials mentioning features or use of this software
	41	* must display the following acknowledgement:
	42	* This product includes software developed by the University of
	43	* California, Berkeley and its contributors.
	44	* 4. Neither the name of the University nor the names of its contributors
	45	* may be used to endorse or promote products derived from this software
	46	* without specific prior written permission.
	47	*
	48	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	49	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	50	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	51	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	52	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	53	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	54	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	55	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	56	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	57	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	58	* SUCH DAMAGE.
	59	*/
	60
e9ce8d39 A	61	#include <sys/param.h>
	62	#include <sys/wait.h>
	63	#include <sys/socket.h>
	64
	65	#include <signal.h>
	66	#include <errno.h>
	67	#include <unistd.h>
	68	#include <stdio.h>
	69	#include <stdlib.h>
	70	#include <string.h>
	71	#include <paths.h>
3b2a1fe8 A	72	#include <crt_externs.h>
	73
	74	#define environ *(_NSGetEnviron())
e9ce8d39 A	75
	76	static struct pid {
	77	struct pid *next;
	78	FILE *fp;
	79	pid_t pid;
	80	} *pidlist;
	81
	82	FILE *
	83	popen(command, type)
	84	const char command, type;
	85	{
	86	struct pid *cur;
	87	FILE *iop;
	88	int pdes[2], pid, twoway;
3b2a1fe8 A	89	char *argv[4];
3b2a1fe8 A	90	struct pid *p;
e9ce8d39 A	91
	92	if (strchr(type, '+')) {
	93	twoway = 1;
	94	type = "r+";
3b2a1fe8 A	95	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
3b2a1fe8 A	96	return (NULL);
e9ce8d39 A	97	} else {
e9ce8d39 A	98	twoway = 0;
3b2a1fe8	99	if ((type != 'r' && type != 'w') \|\| type[1])
e9ce8d39 A	100	return (NULL);
e9ce8d39 A	101	}
3b2a1fe8 A	102	if (pipe(pdes) < 0)
3b2a1fe8 A	103	return (NULL);
e9ce8d39	104
3b2a1fe8 A	105	if ((cur = malloc(sizeof(struct pid))) == NULL) {
	106	(void)close(pdes[0]);
	107	(void)close(pdes[1]);
e9ce8d39	108	return (NULL);
3b2a1fe8 A	109	}
	110
	111	argv[0] = "sh";
	112	argv[1] = "-c";
	113	argv[2] = (char *)command;
	114	argv[3] = NULL;
e9ce8d39 A	115
	116	switch (pid = vfork()) {
	117	case -1: /* Error. */
	118	(void)close(pdes[0]);
	119	(void)close(pdes[1]);
3b2a1fe8	120	free(cur);
e9ce8d39 A	121	return (NULL);
	122	/* NOTREACHED */
	123	case 0: /* Child. */
	124	if (*type == 'r') {
3b2a1fe8 A	125	/*
	126	* The _dup2() to STDIN_FILENO is repeated to avoid
	127	* writing to pdes[1], which might corrupt the
	128	* parent's copy. This isn't good enough in
	129	* general, since the _exit() is no return, so
	130	* the compiler is free to corrupt all the local
	131	* variables.
	132	*/
	133	(void)close(pdes[0]);
e9ce8d39 A	134	if (pdes[1] != STDOUT_FILENO) {
	135	(void)dup2(pdes[1], STDOUT_FILENO);
	136	(void)close(pdes[1]);
3b2a1fe8 A	137	if (twoway)
	138	(void)dup2(STDOUT_FILENO, STDIN_FILENO);
	139	} else if (twoway && (pdes[1] != STDIN_FILENO))
e9ce8d39 A	140	(void)dup2(pdes[1], STDIN_FILENO);
	141	} else {
	142	if (pdes[0] != STDIN_FILENO) {
	143	(void)dup2(pdes[0], STDIN_FILENO);
	144	(void)close(pdes[0]);
	145	}
	146	(void)close(pdes[1]);
3b2a1fe8 A	147	}
	148	for (p = pidlist; p; p = p->next) {
	149	(void)close(fileno(p->fp));
e9ce8d39	150	}
3b2a1fe8	151	execve(_PATH_BSHELL, argv, environ);
e9ce8d39 A	152	_exit(127);
	153	/* NOTREACHED */
	154	}
	155
	156	/* Parent; assume fdopen can't fail. */
	157	if (*type == 'r') {
	158	iop = fdopen(pdes[0], type);
	159	(void)close(pdes[1]);
	160	} else {
	161	iop = fdopen(pdes[1], type);
	162	(void)close(pdes[0]);
	163	}
	164
	165	/* Link into list of file descriptors. */
	166	cur->fp = iop;
	167	cur->pid = pid;
	168	cur->next = pidlist;
	169	pidlist = cur;
	170
	171	return (iop);
	172	}
	173
	174	/*
	175	* pclose --
	176	* Pclose returns -1 if stream is not associated with a `popened' command,
	177	* if already `pclosed', or waitpid returns an error.
	178	*/
	179	int
	180	pclose(iop)
	181	FILE *iop;
	182	{
	183	register struct pid cur, last;
e9ce8d39 A	184	int pstat;
	185	pid_t pid;
	186
	187	/* Find the appropriate file pointer. */
	188	for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next)
	189	if (cur->fp == iop)
	190	break;
	191	if (cur == NULL)
	192	return (-1);
	193
	194	(void)fclose(iop);
	195
	196	do {
3b2a1fe8	197	pid = wait4(cur->pid, &pstat, 0, (struct rusage *)0);
e9ce8d39 A	198	} while (pid == -1 && errno == EINTR);
	199
	200	/* Remove the entry from the linked list. */
	201	if (last == NULL)
	202	pidlist = cur->next;
	203	else
	204	last->next = cur->next;
	205	free(cur);
	206
	207	return (pid == -1 ? -1 : pstat);
	208	}