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')
103 dest = ".";
104 if (dest[0] == '-' && dest[1] == '\0') {
105 dest = bltinlookup("OLDPWD", 1);
106 if (dest == NULL)
107 error("OLDPWD not set");
108 print = 1;
109 }
110 if (dest[0] == '/' ||
111 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) ||
112 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) ||
113 (path = bltinlookup("CDPATH", 1)) == NULL)
114 path = "";
115 while ((p = padvance(&path, NULL, dest)) != NULL) {
116 if (stat(p, &statb) < 0) {
117 if (errno != ENOENT)
118 errno1 = errno;
119 } else if (!S_ISDIR(statb.st_mode))
120 errno1 = ENOTDIR;
121 else {
122 if (!print) {
123 /*
124 * XXX - rethink
125 */
126 if (p[0] == '.' && p[1] == '/' && p[2] != '\0')
127 print = strcmp(p + 2, dest);
128 else
129 print = strcmp(p, dest);
130 }
131 rc = docd(p, print, phys);
132 if (rc >= 0)
133 return getcwderr ? rc : 0;
134 if (errno != ENOENT)
135 errno1 = errno;
136 }
137 }
138 error("%s: %s", dest, strerror(errno1));
139 /*NOTREACHED*/
140 return 0;
141 }
142
143
144 /*
145 * Actually change the directory. In an interactive shell, print the
146 * directory name if "print" is nonzero.
147 */
148 static int
docd(char * dest,int print,int phys)149 docd(char *dest, int print, int phys)
150 {
151 int rc;
152
153 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys));
154
155 /* If logical cd fails, fall back to physical. */
156 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0)
157 return (-1);
158
159 if (print && iflag && curdir) {
160 out1fmt("%s\n", curdir);
161 /*
162 * Ignore write errors to preserve the invariant that the
163 * current directory is changed iff the exit status is 0
164 * (or 1 if -e was given and the full pathname could not be
165 * determined).
166 */
167 flushout(out1);
168 outclearerror(out1);
169 }
170
171 return (rc);
172 }
173
174 static int
cdlogical(char * dest)175 cdlogical(char *dest)
176 {
177 char *p;
178 char *q;
179 char *component;
180 char *path;
181 struct stat statb;
182 int first;
183 int badstat;
184
185 /*
186 * Check each component of the path. If we find a symlink or
187 * something we can't stat, clear curdir to force a getcwd()
188 * next time we get the value of the current directory.
189 */
190 badstat = 0;
191 path = stsavestr(dest);
192 STARTSTACKSTR(p);
193 if (*dest == '/') {
194 STPUTC('/', p);
195 path++;
196 }
197 first = 1;
198 while ((q = getcomponent(&path)) != NULL) {
199 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0'))
200 continue;
201 if (! first)
202 STPUTC('/', p);
203 first = 0;
204 component = q;
205 STPUTS(q, p);
206 if (equal(component, ".."))
207 continue;
208 STACKSTRNUL(p);
209 if (lstat(stackblock(), &statb) < 0) {
210 badstat = 1;
211 break;
212 }
213 }
214
215 INTOFF;
216 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) {
217 INTON;
218 return (-1);
219 }
220 updatepwd(p);
221 INTON;
222 return (0);
223 }
224
225 static int
cdphysical(char * dest)226 cdphysical(char *dest)
227 {
228 char *p;
229 int rc = 0;
230
231 INTOFF;
232 if (chdir(dest) < 0) {
233 INTON;
234 return (-1);
235 }
236 p = findcwd(NULL);
237 if (p == NULL) {
238 warning("warning: failed to get name of current directory");
239 rc = 1;
240 }
241 updatepwd(p);
242 INTON;
243 return (rc);
244 }
245
246 /*
247 * Get the next component of the path name pointed to by *path.
248 * This routine overwrites *path and the string pointed to by it.
249 */
250 static char *
getcomponent(char ** path)251 getcomponent(char **path)
252 {
253 char *p;
254 char *start;
255
256 if ((p = *path) == NULL)
257 return NULL;
258 start = *path;
259 while (*p != '/' && *p != '\0')
260 p++;
261 if (*p == '\0') {
262 *path = NULL;
263 } else {
264 *p++ = '\0';
265 *path = p;
266 }
267 return start;
268 }
269
270
271 static char *
findcwd(char * dir)272 findcwd(char *dir)
273 {
274 char *new;
275 char *p;
276 char *path;
277
278 /*
279 * If our argument is NULL, we don't know the current directory
280 * any more because we traversed a symbolic link or something
281 * we couldn't stat().
282 */
283 if (dir == NULL || curdir == NULL)
284 return getpwd2();
285 path = stsavestr(dir);
286 STARTSTACKSTR(new);
287 if (*dir != '/') {
288 STPUTS(curdir, new);
289 if (STTOPC(new) == '/')
290 STUNPUTC(new);
291 }
292 while ((p = getcomponent(&path)) != NULL) {
293 if (equal(p, "..")) {
294 while (new > stackblock() && (STUNPUTC(new), *new) != '/');
295 } else if (*p != '\0' && ! equal(p, ".")) {
296 STPUTC('/', new);
297 STPUTS(p, new);
298 }
299 }
300 if (new == stackblock())
301 STPUTC('/', new);
302 STACKSTRNUL(new);
303 return stackblock();
304 }
305
306 /*
307 * Update curdir (the name of the current directory) in response to a
308 * cd command. We also call hashcd to let the routines in exec.c know
309 * that the current directory has changed.
310 */
311 static void
updatepwd(char * dir)312 updatepwd(char *dir)
313 {
314 char *prevdir;
315
316 hashcd(); /* update command hash table */
317
318 setvar("PWD", dir, VEXPORT);
319 setvar("OLDPWD", curdir, VEXPORT);
320 prevdir = curdir;
321 curdir = dir ? savestr(dir) : NULL;
322 ckfree(prevdir);
323 }
324
325 int
pwdcmd(int argc __unused,char ** argv __unused)326 pwdcmd(int argc __unused, char **argv __unused)
327 {
328 char *p;
329 int ch, phys;
330
331 phys = Pflag;
332 while ((ch = nextopt("LP")) != '\0') {
333 switch (ch) {
334 case 'L':
335 phys = 0;
336 break;
337 case 'P':
338 phys = 1;
339 break;
340 }
341 }
342
343 if (*argptr != NULL)
344 error("too many arguments");
345
346 if (!phys && getpwd()) {
347 out1str(curdir);
348 out1c('\n');
349 } else {
350 if ((p = getpwd2()) == NULL)
351 error(".: %s", strerror(errno));
352 out1str(p);
353 out1c('\n');
354 }
355
356 return 0;
357 }
358
359 /*
360 * Get the current directory and cache the result in curdir.
361 */
362 static char *
getpwd(void)363 getpwd(void)
364 {
365 char *p;
366
367 if (curdir)
368 return curdir;
369
370 p = getpwd2();
371 if (p != NULL) {
372 INTOFF;
373 curdir = savestr(p);
374 INTON;
375 }
376
377 return curdir;
378 }
379
380 #define MAXPWD 256
381
382 /*
383 * Return the current directory.
384 */
385 static char *
getpwd2(void)386 getpwd2(void)
387 {
388 char *pwd;
389 int i;
390
391 for (i = MAXPWD;; i *= 2) {
392 pwd = stalloc(i);
393 if (getcwd(pwd, i) != NULL)
394 return pwd;
395 stunalloc(pwd);
396 if (errno != ERANGE)
397 break;
398 }
399
400 return NULL;
401 }
402
403 /*
404 * Initialize PWD in a new shell.
405 * If the shell is interactive, we need to warn if this fails.
406 */
407 void
pwd_init(int warn)408 pwd_init(int warn)
409 {
410 char *pwd;
411 struct stat stdot, stpwd;
412
413 pwd = lookupvar("PWD");
414 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 &&
415 stat(pwd, &stpwd) != -1 &&
416 stdot.st_dev == stpwd.st_dev &&
417 stdot.st_ino == stpwd.st_ino) {
418 if (curdir)
419 ckfree(curdir);
420 curdir = savestr(pwd);
421 }
422 if (getpwd() == NULL && warn)
423 out2fmt_flush("sh: cannot determine working directory\n");
424 setvar("PWD", curdir, VEXPORT);
425 }
426