source: mainline/uspace/app/ash/cd.c@ c28a023

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since c28a023 was c28a023, checked in by Josef Cejka <malyzelenyhnus@…>, 17 years ago

Initial commit of ash shell.
It cannot be compiled yet.

  • Property mode set to 100644
File size: 8.8 KB
Line 
1/* $NetBSD: cd.c,v 1.27 1999/07/09 03:05:49 christos Exp $ */
2
3/*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39#include <sys/cdefs.h>
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95";
43#else
44__RCSID("$NetBSD: cd.c,v 1.27 1999/07/09 03:05:49 christos Exp $");
45#endif
46#endif /* not lint */
47
48#include <sys/types.h>
49#include <sys/stat.h>
50#include <stdlib.h>
51#include <string.h>
52#include <unistd.h>
53#include <errno.h>
54
55/*
56 * The cd and pwd commands.
57 */
58
59#include "shell.h"
60#include "var.h"
61#include "nodes.h" /* for jobs.h */
62#include "jobs.h"
63#include "options.h"
64#include "output.h"
65#include "memalloc.h"
66#include "error.h"
67#include "exec.h"
68#include "redir.h"
69#include "mystring.h"
70#include "show.h"
71#include "cd.h"
72
73STATIC int docd (char *, int);
74STATIC char *getcomponent (void);
75STATIC void updatepwd (char *);
76
77char *curdir = NULL; /* current working directory */
78char *prevdir; /* previous working directory */
79STATIC char *cdcomppath;
80
81int
82cdcmd(argc, argv)
83 int argc;
84 char **argv;
85{
86 const char *dest;
87 const char *path;
88 char *p;
89 struct stat statb;
90 int print = 0;
91
92 nextopt(nullstr);
93 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
94 error("HOME not set");
95 if (*dest == '\0')
96 dest = ".";
97 if (dest[0] == '-' && dest[1] == '\0') {
98 dest = prevdir ? prevdir : curdir;
99 print = 1;
100 if (dest)
101 print = 1;
102 else
103 dest = ".";
104 }
105 if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL)
106 path = nullstr;
107 while ((p = padvance(&path, dest)) != NULL) {
108 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
109 if (!print) {
110 /*
111 * XXX - rethink
112 */
113 if (p[0] == '.' && p[1] == '/' && p[2] != '\0')
114 p += 2;
115 print = strcmp(p, dest);
116 }
117 if (docd(p, print) >= 0)
118 return 0;
119
120 }
121 }
122 error("can't cd to %s", dest);
123 /* NOTREACHED */
124}
125
126
127/*
128 * Actually do the chdir. In an interactive shell, print the
129 * directory name if "print" is nonzero.
130 */
131
132STATIC int
133docd(dest, print)
134 char *dest;
135 int print;
136{
137 char *p;
138 char *q;
139 char *component;
140 struct stat statb;
141 int first;
142 int badstat;
143
144 TRACE(("docd(\"%s\", %d) called\n", dest, print));
145
146 /*
147 * Check each component of the path. If we find a symlink or
148 * something we can't stat, clear curdir to force a getcwd()
149 * next time we get the value of the current directory.
150 */
151 badstat = 0;
152 cdcomppath = stalloc(strlen(dest) + 1);
153 scopy(dest, cdcomppath);
154 STARTSTACKSTR(p);
155 if (*dest == '/') {
156 STPUTC('/', p);
157 cdcomppath++;
158 }
159 first = 1;
160 while ((q = getcomponent()) != NULL) {
161 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0'))
162 continue;
163 if (! first)
164 STPUTC('/', p);
165 first = 0;
166 component = q;
167 while (*q)
168 STPUTC(*q++, p);
169 if (equal(component, ".."))
170 continue;
171 STACKSTRNUL(p);
172 if ((lstat(stackblock(), &statb) < 0)
173 || (S_ISLNK(statb.st_mode))) {
174 /* print = 1; */
175 badstat = 1;
176 break;
177 }
178 }
179
180 INTOFF;
181 if (chdir(dest) < 0) {
182 INTON;
183 return -1;
184 }
185 updatepwd(badstat ? NULL : dest);
186 INTON;
187 if (print && iflag && curdir)
188 out1fmt("%s\n", curdir);
189 return 0;
190}
191
192
193/*
194 * Get the next component of the path name pointed to by cdcomppath.
195 * This routine overwrites the string pointed to by cdcomppath.
196 */
197
198STATIC char *
199getcomponent() {
200 char *p;
201 char *start;
202
203 if ((p = cdcomppath) == NULL)
204 return NULL;
205 start = cdcomppath;
206 while (*p != '/' && *p != '\0')
207 p++;
208 if (*p == '\0') {
209 cdcomppath = NULL;
210 } else {
211 *p++ = '\0';
212 cdcomppath = p;
213 }
214 return start;
215}
216
217
218
219/*
220 * Update curdir (the name of the current directory) in response to a
221 * cd command. We also call hashcd to let the routines in exec.c know
222 * that the current directory has changed.
223 */
224
225STATIC void
226updatepwd(dir)
227 char *dir;
228 {
229 char *new;
230 char *p;
231
232 hashcd(); /* update command hash table */
233
234 /*
235 * If our argument is NULL, we don't know the current directory
236 * any more because we traversed a symbolic link or something
237 * we couldn't stat().
238 */
239 if (dir == NULL || curdir == NULL) {
240 if (prevdir)
241 ckfree(prevdir);
242 INTOFF;
243 prevdir = curdir;
244 curdir = NULL;
245 getpwd();
246 setvar("PWD", curdir, VEXPORT|VTEXTFIXED);
247 setvar("OLDPWD", prevdir, VEXPORT|VTEXTFIXED);
248 INTON;
249 return;
250 }
251 cdcomppath = stalloc(strlen(dir) + 1);
252 scopy(dir, cdcomppath);
253 STARTSTACKSTR(new);
254 if (*dir != '/') {
255 p = curdir;
256 while (*p)
257 STPUTC(*p++, new);
258 if (p[-1] == '/')
259 STUNPUTC(new);
260 }
261 while ((p = getcomponent()) != NULL) {
262 if (equal(p, "..")) {
263 while (new > stackblock() && (STUNPUTC(new), *new) != '/');
264 } else if (*p != '\0' && ! equal(p, ".")) {
265 STPUTC('/', new);
266 while (*p)
267 STPUTC(*p++, new);
268 }
269 }
270 if (new == stackblock())
271 STPUTC('/', new);
272 STACKSTRNUL(new);
273 INTOFF;
274 if (prevdir)
275 ckfree(prevdir);
276 prevdir = curdir;
277 curdir = savestr(stackblock());
278 setvar("PWD", curdir, VEXPORT|VTEXTFIXED);
279 setvar("OLDPWD", prevdir, VEXPORT|VTEXTFIXED);
280 INTON;
281}
282
283
284
285int
286pwdcmd(argc, argv)
287 int argc;
288 char **argv;
289{
290 getpwd();
291 out1str(curdir);
292 out1c('\n');
293 return 0;
294}
295
296
297
298
299#define MAXPWD 256
300
301/*
302 * Find out what the current directory is. If we already know the current
303 * directory, this routine returns immediately.
304 */
305void
306getpwd()
307{
308 char buf[MAXPWD];
309
310 if (curdir)
311 return;
312 /*
313 * Things are a bit complicated here; we could have just used
314 * getcwd, but traditionally getcwd is implemented using popen
315 * to /bin/pwd. This creates a problem for us, since we cannot
316 * keep track of the job if it is being ran behind our backs.
317 * So we re-implement getcwd(), and we suppress interrupts
318 * throughout the process. This is not completely safe, since
319 * the user can still break out of it by killing the pwd program.
320 * We still try to use getcwd for systems that we know have a
321 * c implementation of getcwd, that does not open a pipe to
322 * /bin/pwd.
323 */
324#if defined(__NetBSD__) || defined(__SVR4) || defined(__GLIBC__)
325
326 if (getcwd(buf, sizeof(buf)) == NULL) {
327 char *pwd = getenv("PWD");
328 struct stat stdot, stpwd;
329
330 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 &&
331 stat(pwd, &stpwd) != -1 &&
332 stdot.st_dev == stpwd.st_dev &&
333 stdot.st_ino == stpwd.st_ino) {
334 curdir = savestr(pwd);
335 return;
336 }
337 error("getcwd() failed: %s", strerror(errno));
338 }
339 curdir = savestr(buf);
340#else
341 {
342 char *p;
343 int i;
344 int status;
345 struct job *jp;
346 int pip[2];
347
348 INTOFF;
349 if (pipe(pip) < 0)
350 error("Pipe call failed");
351 jp = makejob((union node *)NULL, 1);
352 if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) {
353 (void) close(pip[0]);
354 if (pip[1] != 1) {
355 close(1);
356 copyfd(pip[1], 1);
357 close(pip[1]);
358 }
359 (void) execl("/bin/pwd", "pwd", (char *)0);
360 error("Cannot exec /bin/pwd");
361 }
362 (void) close(pip[1]);
363 pip[1] = -1;
364 p = buf;
365 while ((i = read(pip[0], p, buf + MAXPWD - p)) > 0
366 || (i == -1 && errno == EINTR)) {
367 if (i > 0)
368 p += i;
369 }
370 (void) close(pip[0]);
371 pip[0] = -1;
372 status = waitforjob(jp);
373 if (status != 0)
374 error((char *)0);
375 if (i < 0 || p == buf || p[-1] != '\n')
376 error("pwd command failed");
377 p[-1] = '\0';
378 }
379 curdir = savestr(buf);
380 INTON;
381#endif
382}
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