1 /*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <errno.h>
39 #include <limits.h>
40
41 /*
42 * The cd and pwd commands.
43 */
44
45 #include "shell.h"
46 #include "var.h"
47 #include "nodes.h" /* for jobs.h */
48 #include "jobs.h"
49 #include "options.h"
50 #include "output.h"
51 #include "memalloc.h"
52 #include "error.h"
53 #include "exec.h"
54 #include "redir.h"
55 #include "mystring.h"
56 #include "show.h"
57 #include "cd.h"
58 #include "builtins.h"
59
60 static int cdlogical(char *);
61 static int cdphysical(char *);
62 static int docd(char *, int, int);
63 static char *getcomponent(char **);
64 static char *findcwd(char *);
65 static void updatepwd(char *);
66 static char *getpwd(void);
67 static char *getpwd2(void);
68
69 static char *curdir = NULL; /* current working directory */
70
71 int
cdcmd(int argc __unused,char ** argv __unused)72 cdcmd(int argc __unused, char **argv __unused)
73 {
74 const char *dest;
75 const char *path;
76 char *p;
77 struct stat statb;
78 int ch, phys, print = 0, getcwderr = 0;
79 int rc;
80 int errno1 = ENOENT;
81
82 phys = Pflag;
83 while ((ch = nextopt("eLP")) != '\0') {
84 switch (ch) {
85 case 'e':
86 getcwderr = 1;
87 break;
88 case 'L':
89 phys = 0;
90 break;
91 case 'P':
92 phys = 1;
93 break;
94 }
95 }
96
97 if (*argptr != NULL && argptr[1] != NULL)
98 error("too many arguments");
99
100 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
101 error("HOME not set");
102 if (dest[0] == '-' && dest[1] == '\0') {
103 dest = bltinlookup("OLDPWD", 1);
104 if (dest == NULL)
105 error("OLDPWD not set");
106 print = 1;
107 }
108 if (dest[0] == '/' ||
109 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) ||
110 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) ||
111 (path = bltinlookup("CDPATH", 1)) == NULL)
112 path = "";
113 while ((p = padvance(&path, NULL, dest)) != NULL) {
114 if (stat(p, &statb) < 0) {
115 if (errno != ENOENT)
116 errno1 = errno;
117 } else if (!S_ISDIR(statb.st_mode))
118 errno1 = ENOTDIR;
119 else {
120 if (!print) {
121 /*
122 * XXX - rethink
123 */
124 if (p[0] == '.' && p[1] == '/' && p[2] != '\0')
125 print = strcmp(p + 2, dest);
126 else
127 print = strcmp(p, dest);
128 }
129 rc = docd(p, print, phys);
130 if (rc >= 0)
131 return getcwderr ? rc : 0;
132 if (errno != ENOENT)
133 errno1 = errno;
134 }
135 }
136 error("%s: %s", dest, strerror(errno1));
137 /*NOTREACHED*/
138 return 0;
139 }
140
141
142 /*
143 * Actually change the directory. In an interactive shell, print the
144 * directory name if "print" is nonzero.
145 */
146 static int
docd(char * dest,int print,int phys)147 docd(char *dest, int print, int phys)
148 {
149 int rc;
150
151 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys));
152
153 /* If logical cd fails, fall back to physical. */
154 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0)
155 return (-1);
156
157 if (print && iflag && curdir) {
158 out1fmt("%s\n", curdir);
159 /*
160 * Ignore write errors to preserve the invariant that the
161 * current directory is changed iff the exit status is 0
162 * (or 1 if -e was given and the full pathname could not be
163 * determined).
164 */
165 flushout(out1);
166 outclearerror(out1);
167 }
168
169 return (rc);
170 }
171
172 static int
cdlogical(char * dest)173 cdlogical(char *dest)
174 {
175 char *p;
176 char *q;
177 char *component;
178 char *path;
179 struct stat statb;
180 int first;
181 int badstat;
182
183 /*
184 * Check each component of the path. If we find a symlink or
185 * something we can't stat, clear curdir to force a getcwd()
186 * next time we get the value of the current directory.
187 */
188 badstat = 0;
189 path = stsavestr(dest);
190 STARTSTACKSTR(p);
191 if (*dest == '/') {
192 STPUTC('/', p);
193 path++;
194 }
195 first = 1;
196 while ((q = getcomponent(&path)) != NULL) {
197 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0'))
198 continue;
199 if (! first)
200 STPUTC('/', p);
201 first = 0;
202 component = q;
203 STPUTS(q, p);
204 if (equal(component, ".."))
205 continue;
206 STACKSTRNUL(p);
207 if (lstat(stackblock(), &statb) < 0) {
208 badstat = 1;
209 break;
210 }
211 }
212
213 INTOFF;
214 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) {
215 INTON;
216 return (-1);
217 }
218 updatepwd(p);
219 INTON;
220 return (0);
221 }
222
223 static int
cdphysical(char * dest)224 cdphysical(char *dest)
225 {
226 char *p;
227 int rc = 0;
228
229 INTOFF;
230 if (chdir(dest) < 0) {
231 INTON;
232 return (-1);
233 }
234 p = findcwd(NULL);
235 if (p == NULL) {
236 warning("warning: failed to get name of current directory");
237 rc = 1;
238 }
239 updatepwd(p);
240 INTON;
241 return (rc);
242 }
243
244 /*
245 * Get the next component of the path name pointed to by *path.
246 * This routine overwrites *path and the string pointed to by it.
247 */
248 static char *
getcomponent(char ** path)249 getcomponent(char **path)
250 {
251 char *p;
252 char *start;
253
254 if ((p = *path) == NULL)
255 return NULL;
256 start = *path;
257 while (*p != '/' && *p != '\0')
258 p++;
259 if (*p == '\0') {
260 *path = NULL;
261 } else {
262 *p++ = '\0';
263 *path = p;
264 }
265 return start;
266 }
267
268
269 static char *
findcwd(char * dir)270 findcwd(char *dir)
271 {
272 char *new;
273 char *p;
274 char *path;
275
276 /*
277 * If our argument is NULL, we don't know the current directory
278 * any more because we traversed a symbolic link or something
279 * we couldn't stat().
280 */
281 if (dir == NULL || curdir == NULL)
282 return getpwd2();
283 path = stsavestr(dir);
284 STARTSTACKSTR(new);
285 if (*dir != '/') {
286 STPUTS(curdir, new);
287 if (STTOPC(new) == '/')
288 STUNPUTC(new);
289 }
290 while ((p = getcomponent(&path)) != NULL) {
291 if (equal(p, "..")) {
292 while (new > stackblock() && (STUNPUTC(new), *new) != '/');
293 } else if (*p != '\0' && ! equal(p, ".")) {
294 STPUTC('/', new);
295 STPUTS(p, new);
296 }
297 }
298 if (new == stackblock())
299 STPUTC('/', new);
300 STACKSTRNUL(new);
301 return stackblock();
302 }
303
304 /*
305 * Update curdir (the name of the current directory) in response to a
306 * cd command. We also call hashcd to let the routines in exec.c know
307 * that the current directory has changed.
308 */
309 static void
updatepwd(char * dir)310 updatepwd(char *dir)
311 {
312 char *prevdir;
313
314 hashcd(); /* update command hash table */
315
316 setvar("PWD", dir, VEXPORT);
317 setvar("OLDPWD", curdir, VEXPORT);
318 prevdir = curdir;
319 curdir = dir ? savestr(dir) : NULL;
320 ckfree(prevdir);
321 }
322
323 int
pwdcmd(int argc __unused,char ** argv __unused)324 pwdcmd(int argc __unused, char **argv __unused)
325 {
326 char *p;
327 int ch, phys;
328
329 phys = Pflag;
330 while ((ch = nextopt("LP")) != '\0') {
331 switch (ch) {
332 case 'L':
333 phys = 0;
334 break;
335 case 'P':
336 phys = 1;
337 break;
338 }
339 }
340
341 if (*argptr != NULL)
342 error("too many arguments");
343
344 if (!phys && getpwd()) {
345 out1str(curdir);
346 out1c('\n');
347 } else {
348 if ((p = getpwd2()) == NULL)
349 error(".: %s", strerror(errno));
350 out1str(p);
351 out1c('\n');
352 }
353
354 return 0;
355 }
356
357 /*
358 * Get the current directory and cache the result in curdir.
359 */
360 static char *
getpwd(void)361 getpwd(void)
362 {
363 char *p;
364
365 if (curdir)
366 return curdir;
367
368 p = getpwd2();
369 if (p != NULL) {
370 INTOFF;
371 curdir = savestr(p);
372 INTON;
373 }
374
375 return curdir;
376 }
377
378 #define MAXPWD 256
379
380 /*
381 * Return the current directory.
382 */
383 static char *
getpwd2(void)384 getpwd2(void)
385 {
386 char *pwd;
387 int i;
388
389 for (i = MAXPWD;; i *= 2) {
390 pwd = stalloc(i);
391 if (getcwd(pwd, i) != NULL)
392 return pwd;
393 stunalloc(pwd);
394 if (errno != ERANGE)
395 break;
396 }
397
398 return NULL;
399 }
400
401 /*
402 * Initialize PWD in a new shell.
403 * If the shell is interactive, we need to warn if this fails.
404 */
405 void
pwd_init(int warn)406 pwd_init(int warn)
407 {
408 char *pwd;
409 struct stat stdot, stpwd;
410
411 pwd = lookupvar("PWD");
412 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 &&
413 stat(pwd, &stpwd) != -1 &&
414 stdot.st_dev == stpwd.st_dev &&
415 stdot.st_ino == stpwd.st_ino) {
416 if (curdir)
417 ckfree(curdir);
418 curdir = savestr(pwd);
419 }
420 if (getpwd() == NULL && warn)
421 out2fmt_flush("sh: cannot determine working directory\n");
422 setvar("PWD", curdir, VEXPORT);
423 }
424