redir.c revision 1.17 1 1.17 christos /* $NetBSD: redir.c,v 1.17 1998/07/27 17:12:45 christos Exp $ */
2 1.11 cgd
3 1.1 cgd /*-
4 1.7 jtc * Copyright (c) 1991, 1993
5 1.7 jtc * The Regents of the University of California. All rights reserved.
6 1.1 cgd *
7 1.1 cgd * This code is derived from software contributed to Berkeley by
8 1.1 cgd * Kenneth Almquist.
9 1.1 cgd *
10 1.1 cgd * Redistribution and use in source and binary forms, with or without
11 1.1 cgd * modification, are permitted provided that the following conditions
12 1.1 cgd * are met:
13 1.1 cgd * 1. Redistributions of source code must retain the above copyright
14 1.1 cgd * notice, this list of conditions and the following disclaimer.
15 1.1 cgd * 2. Redistributions in binary form must reproduce the above copyright
16 1.1 cgd * notice, this list of conditions and the following disclaimer in the
17 1.1 cgd * documentation and/or other materials provided with the distribution.
18 1.1 cgd * 3. All advertising materials mentioning features or use of this software
19 1.1 cgd * must display the following acknowledgement:
20 1.1 cgd * This product includes software developed by the University of
21 1.1 cgd * California, Berkeley and its contributors.
22 1.1 cgd * 4. Neither the name of the University nor the names of its contributors
23 1.1 cgd * may be used to endorse or promote products derived from this software
24 1.1 cgd * without specific prior written permission.
25 1.1 cgd *
26 1.1 cgd * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 1.1 cgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 1.1 cgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 1.1 cgd * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 1.1 cgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 1.1 cgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 1.1 cgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 1.1 cgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 1.1 cgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 1.1 cgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 1.1 cgd * SUCH DAMAGE.
37 1.1 cgd */
38 1.1 cgd
39 1.16 christos #include <sys/cdefs.h>
40 1.1 cgd #ifndef lint
41 1.11 cgd #if 0
42 1.12 christos static char sccsid[] = "@(#)redir.c 8.2 (Berkeley) 5/4/95";
43 1.11 cgd #else
44 1.17 christos __RCSID("$NetBSD: redir.c,v 1.17 1998/07/27 17:12:45 christos Exp $");
45 1.11 cgd #endif
46 1.1 cgd #endif /* not lint */
47 1.1 cgd
48 1.12 christos #include <sys/types.h>
49 1.17 christos #include <sys/param.h> /* PIPE_BUF */
50 1.12 christos #include <signal.h>
51 1.12 christos #include <string.h>
52 1.12 christos #include <fcntl.h>
53 1.12 christos #include <errno.h>
54 1.12 christos #include <unistd.h>
55 1.12 christos #include <stdlib.h>
56 1.12 christos
57 1.1 cgd /*
58 1.1 cgd * Code for dealing with input/output redirection.
59 1.1 cgd */
60 1.1 cgd
61 1.1 cgd #include "shell.h"
62 1.1 cgd #include "nodes.h"
63 1.1 cgd #include "jobs.h"
64 1.1 cgd #include "expand.h"
65 1.1 cgd #include "redir.h"
66 1.1 cgd #include "output.h"
67 1.1 cgd #include "memalloc.h"
68 1.1 cgd #include "error.h"
69 1.1 cgd
70 1.1 cgd
71 1.1 cgd #define EMPTY -2 /* marks an unused slot in redirtab */
72 1.17 christos #ifndef PIPE_BUF
73 1.17 christos # define PIPESIZE 4096 /* amount of buffering in a pipe */
74 1.17 christos #else
75 1.17 christos # define PIPESIZE PIPE_BUF
76 1.17 christos #endif
77 1.1 cgd
78 1.1 cgd
79 1.1 cgd MKINIT
80 1.1 cgd struct redirtab {
81 1.1 cgd struct redirtab *next;
82 1.1 cgd short renamed[10];
83 1.1 cgd };
84 1.1 cgd
85 1.1 cgd
86 1.1 cgd MKINIT struct redirtab *redirlist;
87 1.1 cgd
88 1.13 christos /*
89 1.7 jtc * We keep track of whether or not fd0 has been redirected. This is for
90 1.7 jtc * background commands, where we want to redirect fd0 to /dev/null only
91 1.13 christos * if it hasn't already been redirected.
92 1.7 jtc */
93 1.4 sef int fd0_redirected = 0;
94 1.1 cgd
95 1.12 christos STATIC void openredirect __P((union node *, char[10 ]));
96 1.12 christos STATIC int openhere __P((union node *));
97 1.1 cgd
98 1.1 cgd
99 1.1 cgd /*
100 1.1 cgd * Process a list of redirection commands. If the REDIR_PUSH flag is set,
101 1.1 cgd * old file descriptors are stashed away so that the redirection can be
102 1.1 cgd * undone by calling popredir. If the REDIR_BACKQ flag is set, then the
103 1.1 cgd * standard output, and the standard error if it becomes a duplicate of
104 1.1 cgd * stdout, is saved in memory.
105 1.1 cgd */
106 1.1 cgd
107 1.1 cgd void
108 1.1 cgd redirect(redir, flags)
109 1.1 cgd union node *redir;
110 1.1 cgd int flags;
111 1.1 cgd {
112 1.1 cgd union node *n;
113 1.16 christos struct redirtab *sv = NULL;
114 1.1 cgd int i;
115 1.1 cgd int fd;
116 1.15 christos int try;
117 1.13 christos char memory[10]; /* file descriptors to write to memory */
118 1.1 cgd
119 1.1 cgd for (i = 10 ; --i >= 0 ; )
120 1.1 cgd memory[i] = 0;
121 1.1 cgd memory[1] = flags & REDIR_BACKQ;
122 1.1 cgd if (flags & REDIR_PUSH) {
123 1.1 cgd sv = ckmalloc(sizeof (struct redirtab));
124 1.1 cgd for (i = 0 ; i < 10 ; i++)
125 1.1 cgd sv->renamed[i] = EMPTY;
126 1.1 cgd sv->next = redirlist;
127 1.1 cgd redirlist = sv;
128 1.1 cgd }
129 1.1 cgd for (n = redir ; n ; n = n->nfile.next) {
130 1.1 cgd fd = n->nfile.fd;
131 1.15 christos try = 0;
132 1.13 christos if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) &&
133 1.13 christos n->ndup.dupfd == fd)
134 1.13 christos continue; /* redirect from/to same file descriptor */
135 1.15 christos
136 1.1 cgd if ((flags & REDIR_PUSH) && sv->renamed[fd] == EMPTY) {
137 1.1 cgd INTOFF;
138 1.15 christos again:
139 1.15 christos if ((i = fcntl(fd, F_DUPFD, 10)) == -1) {
140 1.15 christos switch (errno) {
141 1.15 christos case EBADF:
142 1.15 christos if (!try) {
143 1.15 christos openredirect(n, memory);
144 1.15 christos try++;
145 1.15 christos goto again;
146 1.15 christos }
147 1.15 christos /* FALLTHROUGH*/
148 1.15 christos default:
149 1.15 christos INTON;
150 1.15 christos error("%d: %s", fd, strerror(errno));
151 1.15 christos break;
152 1.15 christos }
153 1.15 christos }
154 1.15 christos if (!try) {
155 1.1 cgd sv->renamed[fd] = i;
156 1.1 cgd close(fd);
157 1.1 cgd }
158 1.1 cgd INTON;
159 1.1 cgd } else {
160 1.1 cgd close(fd);
161 1.1 cgd }
162 1.7 jtc if (fd == 0)
163 1.7 jtc fd0_redirected++;
164 1.15 christos if (!try)
165 1.15 christos openredirect(n, memory);
166 1.1 cgd }
167 1.1 cgd if (memory[1])
168 1.1 cgd out1 = &memout;
169 1.1 cgd if (memory[2])
170 1.1 cgd out2 = &memout;
171 1.1 cgd }
172 1.1 cgd
173 1.1 cgd
174 1.1 cgd STATIC void
175 1.1 cgd openredirect(redir, memory)
176 1.1 cgd union node *redir;
177 1.1 cgd char memory[10];
178 1.1 cgd {
179 1.1 cgd int fd = redir->nfile.fd;
180 1.1 cgd char *fname;
181 1.1 cgd int f;
182 1.1 cgd
183 1.1 cgd /*
184 1.1 cgd * We suppress interrupts so that we won't leave open file
185 1.1 cgd * descriptors around. This may not be such a good idea because
186 1.1 cgd * an open of a device or a fifo can block indefinitely.
187 1.1 cgd */
188 1.1 cgd INTOFF;
189 1.1 cgd memory[fd] = 0;
190 1.1 cgd switch (redir->nfile.type) {
191 1.1 cgd case NFROM:
192 1.1 cgd fname = redir->nfile.expfname;
193 1.1 cgd if ((f = open(fname, O_RDONLY)) < 0)
194 1.1 cgd error("cannot open %s: %s", fname, errmsg(errno, E_OPEN));
195 1.1 cgd movefd:
196 1.1 cgd if (f != fd) {
197 1.1 cgd copyfd(f, fd);
198 1.1 cgd close(f);
199 1.1 cgd }
200 1.1 cgd break;
201 1.1 cgd case NTO:
202 1.1 cgd fname = redir->nfile.expfname;
203 1.1 cgd #ifdef O_CREAT
204 1.1 cgd if ((f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0)
205 1.1 cgd error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
206 1.1 cgd #else
207 1.1 cgd if ((f = creat(fname, 0666)) < 0)
208 1.1 cgd error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
209 1.1 cgd #endif
210 1.1 cgd goto movefd;
211 1.1 cgd case NAPPEND:
212 1.1 cgd fname = redir->nfile.expfname;
213 1.1 cgd #ifdef O_APPEND
214 1.1 cgd if ((f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0)
215 1.1 cgd error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
216 1.1 cgd #else
217 1.1 cgd if ((f = open(fname, O_WRONLY)) < 0
218 1.1 cgd && (f = creat(fname, 0666)) < 0)
219 1.1 cgd error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
220 1.7 jtc lseek(f, (off_t)0, 2);
221 1.1 cgd #endif
222 1.1 cgd goto movefd;
223 1.1 cgd case NTOFD:
224 1.1 cgd case NFROMFD:
225 1.1 cgd if (redir->ndup.dupfd >= 0) { /* if not ">&-" */
226 1.1 cgd if (memory[redir->ndup.dupfd])
227 1.1 cgd memory[fd] = 1;
228 1.1 cgd else
229 1.1 cgd copyfd(redir->ndup.dupfd, fd);
230 1.1 cgd }
231 1.1 cgd break;
232 1.1 cgd case NHERE:
233 1.1 cgd case NXHERE:
234 1.1 cgd f = openhere(redir);
235 1.1 cgd goto movefd;
236 1.1 cgd default:
237 1.1 cgd abort();
238 1.1 cgd }
239 1.1 cgd INTON;
240 1.1 cgd }
241 1.1 cgd
242 1.1 cgd
243 1.1 cgd /*
244 1.1 cgd * Handle here documents. Normally we fork off a process to write the
245 1.1 cgd * data to a pipe. If the document is short, we can stuff the data in
246 1.1 cgd * the pipe without forking.
247 1.1 cgd */
248 1.1 cgd
249 1.1 cgd STATIC int
250 1.1 cgd openhere(redir)
251 1.1 cgd union node *redir;
252 1.1 cgd {
253 1.1 cgd int pip[2];
254 1.12 christos int len = 0;
255 1.1 cgd
256 1.1 cgd if (pipe(pip) < 0)
257 1.1 cgd error("Pipe call failed");
258 1.1 cgd if (redir->type == NHERE) {
259 1.1 cgd len = strlen(redir->nhere.doc->narg.text);
260 1.1 cgd if (len <= PIPESIZE) {
261 1.1 cgd xwrite(pip[1], redir->nhere.doc->narg.text, len);
262 1.1 cgd goto out;
263 1.1 cgd }
264 1.1 cgd }
265 1.1 cgd if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
266 1.1 cgd close(pip[0]);
267 1.1 cgd signal(SIGINT, SIG_IGN);
268 1.1 cgd signal(SIGQUIT, SIG_IGN);
269 1.1 cgd signal(SIGHUP, SIG_IGN);
270 1.1 cgd #ifdef SIGTSTP
271 1.1 cgd signal(SIGTSTP, SIG_IGN);
272 1.1 cgd #endif
273 1.1 cgd signal(SIGPIPE, SIG_DFL);
274 1.1 cgd if (redir->type == NHERE)
275 1.1 cgd xwrite(pip[1], redir->nhere.doc->narg.text, len);
276 1.1 cgd else
277 1.1 cgd expandhere(redir->nhere.doc, pip[1]);
278 1.1 cgd _exit(0);
279 1.1 cgd }
280 1.1 cgd out:
281 1.1 cgd close(pip[1]);
282 1.1 cgd return pip[0];
283 1.1 cgd }
284 1.1 cgd
285 1.1 cgd
286 1.1 cgd
287 1.1 cgd /*
288 1.1 cgd * Undo the effects of the last redirection.
289 1.1 cgd */
290 1.1 cgd
291 1.1 cgd void
292 1.1 cgd popredir() {
293 1.14 tls struct redirtab *rp = redirlist;
294 1.1 cgd int i;
295 1.1 cgd
296 1.1 cgd for (i = 0 ; i < 10 ; i++) {
297 1.1 cgd if (rp->renamed[i] != EMPTY) {
298 1.7 jtc if (i == 0)
299 1.7 jtc fd0_redirected--;
300 1.1 cgd close(i);
301 1.1 cgd if (rp->renamed[i] >= 0) {
302 1.1 cgd copyfd(rp->renamed[i], i);
303 1.1 cgd close(rp->renamed[i]);
304 1.1 cgd }
305 1.1 cgd }
306 1.1 cgd }
307 1.1 cgd INTOFF;
308 1.1 cgd redirlist = rp->next;
309 1.1 cgd ckfree(rp);
310 1.1 cgd INTON;
311 1.1 cgd }
312 1.1 cgd
313 1.1 cgd /*
314 1.1 cgd * Undo all redirections. Called on error or interrupt.
315 1.1 cgd */
316 1.1 cgd
317 1.1 cgd #ifdef mkinit
318 1.1 cgd
319 1.1 cgd INCLUDE "redir.h"
320 1.1 cgd
321 1.1 cgd RESET {
322 1.1 cgd while (redirlist)
323 1.1 cgd popredir();
324 1.1 cgd }
325 1.1 cgd
326 1.1 cgd SHELLPROC {
327 1.1 cgd clearredir();
328 1.1 cgd }
329 1.1 cgd
330 1.1 cgd #endif
331 1.1 cgd
332 1.7 jtc /* Return true if fd 0 has already been redirected at least once. */
333 1.7 jtc int
334 1.7 jtc fd0_redirected_p () {
335 1.7 jtc return fd0_redirected != 0;
336 1.7 jtc }
337 1.1 cgd
338 1.1 cgd /*
339 1.1 cgd * Discard all saved file descriptors.
340 1.1 cgd */
341 1.1 cgd
342 1.1 cgd void
343 1.1 cgd clearredir() {
344 1.14 tls struct redirtab *rp;
345 1.1 cgd int i;
346 1.1 cgd
347 1.1 cgd for (rp = redirlist ; rp ; rp = rp->next) {
348 1.1 cgd for (i = 0 ; i < 10 ; i++) {
349 1.1 cgd if (rp->renamed[i] >= 0) {
350 1.1 cgd close(rp->renamed[i]);
351 1.1 cgd }
352 1.1 cgd rp->renamed[i] = EMPTY;
353 1.1 cgd }
354 1.1 cgd }
355 1.1 cgd }
356 1.1 cgd
357 1.1 cgd
358 1.1 cgd
359 1.1 cgd /*
360 1.7 jtc * Copy a file descriptor to be >= to. Returns -1
361 1.1 cgd * if the source file descriptor is closed, EMPTY if there are no unused
362 1.1 cgd * file descriptors left.
363 1.1 cgd */
364 1.1 cgd
365 1.1 cgd int
366 1.13 christos copyfd(from, to)
367 1.9 cgd int from;
368 1.9 cgd int to;
369 1.9 cgd {
370 1.1 cgd int newfd;
371 1.1 cgd
372 1.1 cgd newfd = fcntl(from, F_DUPFD, to);
373 1.13 christos if (newfd < 0) {
374 1.13 christos if (errno == EMFILE)
375 1.13 christos return EMPTY;
376 1.13 christos else
377 1.13 christos error("%d: %s", from, strerror(errno));
378 1.13 christos }
379 1.1 cgd return newfd;
380 1.1 cgd }
381