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 *
Fopen(file,mode)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 *
Fdopen(fd,mode)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
Fclose(fp)75 Fclose(fp)
76 FILE *fp;
77 {
78 unregister_file(fp);
79 return fclose(fp);
80 }
81
82 FILE *
Popen(cmd,mode)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
Pclose(ptr)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
close_all_files()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
register_file(fp,pipe)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
unregister_file(fp)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*/
run_command(cmd,mask,infd,outfd,a0,a1,a2)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*/
start_command(cmd,mask,infd,outfd,a0,a1,a2)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
prepare_child(mask,infd,outfd)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
wait_command(pid)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 *
findchild(pid)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
delchild(cp)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
sigchild()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 */
wait_child(pid)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 */
free_child(pid)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 }
340