[unix-history] / usr.bin / mail / popen.c

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 */

#ifndef lint
static char sccsid[] = "@(#)popen.c	5.16 (Berkeley) 4/1/91";
#endif /* not lint */

#include "rcv.h"
#include <sys/signal.h>
#include <sys/wait.h>

#define READ 0
#define WRITE 1
static int *pid;

struct fp {
	FILE *fp;
	int pipe;
	struct fp *link;
};
static struct fp *fp_head;

FILE *
Fopen(file, mode)
	char *file, *mode;
{
	FILE *fp;

	if ((fp = fopen(file, mode)) != NULL)
		register_file(fp, 0);
	return fp;
}

FILE *
Fdopen(fd, mode)
	char *mode;
{
	FILE *fp;

	if ((fp = fdopen(fd, mode)) != NULL)
		register_file(fp, 0);
	return fp;
}

Fclose(fp)
	FILE *fp;
{
	unregister_file(fp);
	return fclose(fp);
}

FILE *
Popen(cmd, mode)
	char *cmd;
	char *mode;
{
	int p[2];
	int myside, hisside, fd0, fd1;
	FILE *fp;

	if (pid == 0)
		pid = (int *) malloc((unsigned) sizeof (int) * getdtablesize());
	if (pipe(p) < 0)
		return NULL;
	if (*mode == 'r') {
		myside = p[READ];
		fd0 = -1;
		hisside = fd1 = p[WRITE];
	} else {
		myside = p[WRITE];
		hisside = fd0 = p[READ];
		fd1 = -1;
	}
	if ((pid[myside] = start_command(cmd, 0, fd0, fd1, NOSTR)) < 0) {
		close(p[READ]);
		close(p[WRITE]);
		return NULL;
	}
	(void) close(hisside);
	if ((fp = fdopen(myside, mode)) != NULL)
		register_file(fp, 1);
	return fp;
}

Pclose(ptr)
	FILE *ptr;
{
	int i;
	int omask;

	i = fileno(ptr);
	unregister_file(ptr);
	(void) fclose(ptr);
	omask = sigblock(sigmask(SIGINT)|sigmask(SIGHUP));
	i = wait_child(pid[i]);
	sigsetmask(omask);
	return i;
}

close_all_files()
{

	while (fp_head)
		if (fp_head->pipe)
			(void) Pclose(fp_head->fp);
		else
			(void) Fclose(fp_head->fp);
}

register_file(fp, pipe)
	FILE *fp;
{
	struct fp *fpp;

	if ((fpp = (struct fp *) malloc(sizeof *fpp)) == NULL)
		panic("Out of memory");
	fpp->fp = fp;
	fpp->pipe = pipe;
	fpp->link = fp_head;
	fp_head = fpp;
}

unregister_file(fp)
	FILE *fp;
{
	struct fp **pp, *p;

	for (pp = &fp_head; p = *pp; pp = &p->link)
		if (p->fp == fp) {
			*pp = p->link;
			free((char *) p);
			return;
		}
	/* XXX
	 * Ignore this for now; there may still be uncaught
	 * duplicate closes.
	panic("Invalid file pointer");
	*/
}

/*
 * Run a command without a shell, with optional arguments and splicing
 * of stdin and stdout.  The command name can be a sequence of words.
 * Signals must be handled by the caller.
 * "Mask" contains the signals to ignore in the new process.
 * SIGINT is enabled unless it's in the mask.
 */
/*VARARGS4*/
run_command(cmd, mask, infd, outfd, a0, a1, a2)
	char *cmd;
	int mask, infd, outfd;
	char *a0, *a1, *a2;
{
	int pid;

	if ((pid = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0)
		return -1;
	return wait_command(pid);
}

/*VARARGS4*/
start_command(cmd, mask, infd, outfd, a0, a1, a2)
	char *cmd;
	int mask, infd, outfd;
	char *a0, *a1, *a2;
{
	int pid;

	if ((pid = vfork()) < 0) {
		perror("fork");
		return -1;
	}
	if (pid == 0) {
		char *argv[100];
		int i = getrawlist(cmd, argv, sizeof argv / sizeof *argv);

		if ((argv[i++] = a0) != NOSTR &&
		    (argv[i++] = a1) != NOSTR &&
		    (argv[i++] = a2) != NOSTR)
			argv[i] = NOSTR;
		prepare_child(mask, infd, outfd);
		execvp(argv[0], argv);
		perror(argv[0]);
		_exit(1);
	}
	return pid;
}

prepare_child(mask, infd, outfd)
	int mask, infd, outfd;
{
	int i;

	if (infd >= 0)
		dup2(infd, 0);
	if (outfd >= 0)
		dup2(outfd, 1);
	for (i = getdtablesize(); --i > 2;)
		close(i);
	for (i = 1; i <= NSIG; i++)
		if (mask & sigmask(i))
			(void) signal(i, SIG_IGN);
	if ((mask & sigmask(SIGINT)) == 0)
		(void) signal(SIGINT, SIG_DFL);
	(void) sigsetmask(0);
}

wait_command(pid)
	int pid;
{

	if (wait_child(pid) < 0) {
		printf("Fatal error in process.\n");
		return -1;
	}
	return 0;
}

struct child {
	int pid;
	char done;
	char free;
	union wait status;
	struct child *link;
};
static struct child *child;

struct child *
findchild(pid)
	int pid;
{
	register struct child **cpp;

	for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid;
	     cpp = &(*cpp)->link)
			;
	if (*cpp == NULL) {
		*cpp = (struct child *) malloc(sizeof (struct child));
		(*cpp)->pid = pid;
		(*cpp)->done = (*cpp)->free = 0;
		(*cpp)->link = NULL;
	}
	return *cpp;
}

delchild(cp)
	register struct child *cp;
{
	register struct child **cpp;

	for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link)
		;
	*cpp = cp->link;
	free((char *) cp);
}

void
sigchild()
{
	int pid;
	union wait status;
	register struct child *cp;

	while ((pid =
	    wait3((int *)&status, WNOHANG, (struct rusage *)0)) > 0) {
		cp = findchild(pid);
		if (cp->free)
			delchild(cp);
		else {
			cp->done = 1;
			cp->status = status;
		}
	}
}

union wait wait_status;

/*
 * Wait for a specific child to die.
 */
wait_child(pid)
	int pid;
{
	int mask = sigblock(sigmask(SIGCHLD));
	register struct child *cp = findchild(pid);

	while (!cp->done)
		sigpause(mask);
	wait_status = cp->status;
	delchild(cp);
	sigsetmask(mask);
	return wait_status.w_status ? -1 : 0;
}

/*
 * Mark a child as don't care.
 */
free_child(pid)
	int pid;
{
	int mask = sigblock(sigmask(SIGCHLD));
	register struct child *cp = findchild(pid);

	if (cp->done)
		delchild(cp);
	else
		cp->free = 1;
	sigsetmask(mask);
}
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1980 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#ifndef lint
	35	static char sccsid[] = "@(#)popen.c 5.16 (Berkeley) 4/1/91";
	36	#endif /* not lint */
	37
	38	#include "rcv.h"
	39	#include <sys/signal.h>
	40	#include <sys/wait.h>
	41
	42	#define READ 0
	43	#define WRITE 1
	44	static int *pid;
	45
	46	struct fp {
	47	FILE *fp;
	48	int pipe;
	49	struct fp *link;
	50	};
	51	static struct fp *fp_head;
	52
	53	FILE *
	54	Fopen(file, mode)
	55	char file, mode;
	56	{
	57	FILE *fp;
	58
	59	if ((fp = fopen(file, mode)) != NULL)
	60	register_file(fp, 0);
	61	return fp;
	62	}
	63
	64	FILE *
65	Fdopen(fd, mode)
66	char *mode;
67	{
68	FILE *fp;
69
70	if ((fp = fdopen(fd, mode)) != NULL)
71	register_file(fp, 0);
72	return fp;
73	}
74
75	Fclose(fp)
76	FILE *fp;
77	{
78	unregister_file(fp);
79	return fclose(fp);
80	}
81
82	FILE *
83	Popen(cmd, mode)
84	char *cmd;
85	char *mode;
86	{
87	int p[2];
88	int myside, hisside, fd0, fd1;
89	FILE *fp;
90
91	if (pid == 0)
92	pid = (int ) malloc((unsigned) sizeof (int) getdtablesize());
93	if (pipe(p) < 0)
94	return NULL;
95	if (*mode == 'r') {
96	myside = p[READ];
97	fd0 = -1;
98	hisside = fd1 = p[WRITE];
99	} else {
100	myside = p[WRITE];
101	hisside = fd0 = p[READ];
102	fd1 = -1;
103	}
104	if ((pid[myside] = start_command(cmd, 0, fd0, fd1, NOSTR)) < 0) {
105	close(p[READ]);
106	close(p[WRITE]);
107	return NULL;
108	}
109	(void) close(hisside);
110	if ((fp = fdopen(myside, mode)) != NULL)
111	register_file(fp, 1);
112	return fp;
113	}
114
115	Pclose(ptr)
116	FILE *ptr;
117	{
118	int i;
119	int omask;
120
121	i = fileno(ptr);
122	unregister_file(ptr);
123	(void) fclose(ptr);
124	omask = sigblock(sigmask(SIGINT)\|sigmask(SIGHUP));
125	i = wait_child(pid[i]);
126	sigsetmask(omask);
127	return i;
128	}
129
130	close_all_files()
131	{
132
133	while (fp_head)
134	if (fp_head->pipe)
135	(void) Pclose(fp_head->fp);
136	else
137	(void) Fclose(fp_head->fp);
138	}
139
140	register_file(fp, pipe)
141	FILE *fp;
142	{
143	struct fp *fpp;
144
145	if ((fpp = (struct fp ) malloc(sizeof fpp)) == NULL)
146	panic("Out of memory");
147	fpp->fp = fp;
148	fpp->pipe = pipe;
149	fpp->link = fp_head;
150	fp_head = fpp;
151	}
152
153	unregister_file(fp)
154	FILE *fp;
155	{
156	struct fp *pp, p;
157
158	for (pp = &fp_head; p = *pp; pp = &p->link)
159	if (p->fp == fp) {
160	*pp = p->link;
161	free((char *) p);
162	return;
163	}
164	/* XXX
165	* Ignore this for now; there may still be uncaught
166	* duplicate closes.
167	panic("Invalid file pointer");
168	*/
169	}
170
171	/*
172	* Run a command without a shell, with optional arguments and splicing
173	* of stdin and stdout. The command name can be a sequence of words.
174	* Signals must be handled by the caller.
175	* "Mask" contains the signals to ignore in the new process.
176	* SIGINT is enabled unless it's in the mask.
177	*/
178	/VARARGS4/
179	run_command(cmd, mask, infd, outfd, a0, a1, a2)
180	char *cmd;
181	int mask, infd, outfd;
182	char a0, a1, *a2;
183	{
184	int pid;
185
186	if ((pid = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0)
187	return -1;
188	return wait_command(pid);
189	}
190
191	/VARARGS4/
192	start_command(cmd, mask, infd, outfd, a0, a1, a2)
193	char *cmd;
194	int mask, infd, outfd;
195	char a0, a1, *a2;
196	{
197	int pid;
198
199	if ((pid = vfork()) < 0) {
200	perror("fork");
201	return -1;
202	}
203	if (pid == 0) {
204	char *argv[100];
205	int i = getrawlist(cmd, argv, sizeof argv / sizeof *argv);
206
207	if ((argv[i++] = a0) != NOSTR &&
208	(argv[i++] = a1) != NOSTR &&
209	(argv[i++] = a2) != NOSTR)
210	argv[i] = NOSTR;
211	prepare_child(mask, infd, outfd);
212	execvp(argv[0], argv);
213	perror(argv[0]);
214	_exit(1);
215	}
216	return pid;
217	}
218
219	prepare_child(mask, infd, outfd)
220	int mask, infd, outfd;
221	{
222	int i;
223
224	if (infd >= 0)
225	dup2(infd, 0);
226	if (outfd >= 0)
227	dup2(outfd, 1);
228	for (i = getdtablesize(); --i > 2;)
229	close(i);
230	for (i = 1; i <= NSIG; i++)
231	if (mask & sigmask(i))
232	(void) signal(i, SIG_IGN);
233	if ((mask & sigmask(SIGINT)) == 0)
234	(void) signal(SIGINT, SIG_DFL);
235	(void) sigsetmask(0);
236	}
237
238	wait_command(pid)
239	int pid;
240	{
241
242	if (wait_child(pid) < 0) {
243	printf("Fatal error in process.\n");
244	return -1;
245	}
246	return 0;
247	}
248
249	struct child {
250	int pid;
251	char done;
252	char free;
253	union wait status;
254	struct child *link;
255	};
256	static struct child *child;
257
258	struct child *
259	findchild(pid)
260	int pid;
261	{
262	register struct child **cpp;
263
264	for (cpp = &child; cpp != NULL && (cpp)->pid != pid;
265	cpp = &(*cpp)->link)
266	;
267	if (*cpp == NULL) {
268	cpp = (struct child ) malloc(sizeof (struct child));
269	(*cpp)->pid = pid;
270	(cpp)->done = (cpp)->free = 0;
271	(*cpp)->link = NULL;
272	}
273	return *cpp;
274	}
275
276	delchild(cp)
277	register struct child *cp;
278	{
279	register struct child **cpp;
280
281	for (cpp = &child; cpp != cp; cpp = &(cpp)->link)
282	;
283	*cpp = cp->link;
284	free((char *) cp);
285	}
286
287	void
288	sigchild()
289	{
290	int pid;
291	union wait status;
292	register struct child *cp;
293
294	while ((pid =
295	wait3((int )&status, WNOHANG, (struct rusage )0)) > 0) {
296	cp = findchild(pid);
297	if (cp->free)
298	delchild(cp);
299	else {
300	cp->done = 1;
301	cp->status = status;
302	}
303	}
304	}
305
306	union wait wait_status;
307
308	/*
309	* Wait for a specific child to die.
310	*/
311	wait_child(pid)
312	int pid;
313	{
314	int mask = sigblock(sigmask(SIGCHLD));
315	register struct child *cp = findchild(pid);
316
317	while (!cp->done)
318	sigpause(mask);
319	wait_status = cp->status;
320	delchild(cp);
321	sigsetmask(mask);
322	return wait_status.w_status ? -1 : 0;
323	}
324
325	/*
326	* Mark a child as don't care.
327	*/
328	free_child(pid)
329	int pid;
330	{
331	int mask = sigblock(sigmask(SIGCHLD));
332	register struct child *cp = findchild(pid);
333
334	if (cp->done)
335	delchild(cp);
336	else
337	cp->free = 1;
338	sigsetmask(mask);
339	}