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 * 4. 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 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <errno.h>
47 #include <limits.h>
48
49 /*
50 * The cd and pwd commands.
51 */
52
53 #include "shell.h"
54 #include "var.h"
55 #include "nodes.h" /* for jobs.h */
56 #include "jobs.h"
57 #include "options.h"
58 #include "output.h"
59 #include "memalloc.h"
60 #include "error.h"
61 #include "exec.h"
62 #include "redir.h"
63 #include "mystring.h"
64 #include "show.h"
65 #include "cd.h"
66 #include "builtins.h"
67
68 static int cdlogical(char *);
69 static int cdphysical(char *);
70 static int docd(char *, int, int);
71 static char *getcomponent(void);
72 static char *findcwd(char *);
73 static void updatepwd(char *);
74 static char *getpwd(void);
75 static char *getpwd2(void);
76
77 static char *curdir = NULL; /* current working directory */
78 static char *prevdir; /* previous working directory */
79 static char *cdcomppath;
80
81 int
cdcmd(int argc __unused,char ** argv __unused)82 cdcmd(int argc __unused, char **argv __unused)
83 {
84 const char *dest;
85 const char *path;
86 char *p;
87 struct stat statb;
88 int ch, phys, print = 0, getcwderr = 0;
89 int rc;
90 int errno1 = ENOENT;
91
92 phys = Pflag;
93 while ((ch = nextopt("eLP")) != '\0') {
94 switch (ch) {
95 case 'e':
96 getcwderr = 1;
97 break;
98 case 'L':
99 phys = 0;
100 break;
101 case 'P':
102 phys = 1;
103 break;
104 }
105 }
106
107 if (*argptr != NULL && argptr[1] != NULL)
108 error("too many arguments");
109
110 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
111 error("HOME not set");
112 if (*dest == '\0')
113 dest = ".";
114 if (dest[0] == '-' && dest[1] == '\0') {
115 dest = prevdir ? prevdir : curdir;
116 if (dest)
117 print = 1;
118 else
119 dest = ".";
120 }
121 if (dest[0] == '/' ||
122 (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) ||
123 (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) ||
124 (path = bltinlookup("CDPATH", 1)) == NULL)
125 path = nullstr;
126 while ((p = padvance(&path, dest)) != NULL) {
127 if (stat(p, &statb) < 0) {
128 if (errno != ENOENT)
129 errno1 = errno;
130 } else if (!S_ISDIR(statb.st_mode))
131 errno1 = ENOTDIR;
132 else {
133 if (!print) {
134 /*
135 * XXX - rethink
136 */
137 if (p[0] == '.' && p[1] == '/' && p[2] != '\0')
138 print = strcmp(p + 2, dest);
139 else
140 print = strcmp(p, dest);
141 }
142 rc = docd(p, print, phys);
143 if (rc >= 0)
144 return getcwderr ? rc : 0;
145 if (errno != ENOENT)
146 errno1 = errno;
147 }
148 }
149 error("%s: %s", dest, strerror(errno1));
150 /*NOTREACHED*/
151 return 0;
152 }
153
154
155 /*
156 * Actually change the directory. In an interactive shell, print the
157 * directory name if "print" is nonzero.
158 */
159 static int
docd(char * dest,int print,int phys)160 docd(char *dest, int print, int phys)
161 {
162 int rc;
163
164 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys));
165
166 /* If logical cd fails, fall back to physical. */
167 if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0)
168 return (-1);
169
170 if (print && iflag && curdir)
171 out1fmt("%s\n", curdir);
172
173 return (rc);
174 }
175
176 static int
cdlogical(char * dest)177 cdlogical(char *dest)
178 {
179 char *p;
180 char *q;
181 char *component;
182 struct stat statb;
183 int first;
184 int badstat;
185 size_t len;
186
187 /*
188 * Check each component of the path. If we find a symlink or
189 * something we can't stat, clear curdir to force a getcwd()
190 * next time we get the value of the current directory.
191 */
192 badstat = 0;
193 len = strlen(dest);
194 cdcomppath = stalloc(len + 1);
195 memcpy(cdcomppath, dest, len + 1);
196 STARTSTACKSTR(p);
197 if (*dest == '/') {
198 STPUTC('/', p);
199 cdcomppath++;
200 }
201 first = 1;
202 while ((q = getcomponent()) != NULL) {
203 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0'))
204 continue;
205 if (! first)
206 STPUTC('/', p);
207 first = 0;
208 component = q;
209 STPUTS(q, p);
210 if (equal(component, ".."))
211 continue;
212 STACKSTRNUL(p);
213 if (lstat(stackblock(), &statb) < 0) {
214 badstat = 1;
215 break;
216 }
217 }
218
219 INTOFF;
220 if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) {
221 INTON;
222 return (-1);
223 }
224 updatepwd(p);
225 INTON;
226 return (0);
227 }
228
229 static int
cdphysical(char * dest)230 cdphysical(char *dest)
231 {
232 char *p;
233 int rc = 0;
234
235 INTOFF;
236 if (chdir(dest) < 0) {
237 INTON;
238 return (-1);
239 }
240 p = findcwd(NULL);
241 if (p == NULL) {
242 warning("warning: failed to get name of current directory");
243 rc = 1;
244 }
245 updatepwd(p);
246 INTON;
247 return (rc);
248 }
249
250 /*
251 * Get the next component of the path name pointed to by cdcomppath.
252 * This routine overwrites the string pointed to by cdcomppath.
253 */
254 static char *
getcomponent(void)255 getcomponent(void)
256 {
257 char *p;
258 char *start;
259
260 if ((p = cdcomppath) == NULL)
261 return NULL;
262 start = cdcomppath;
263 while (*p != '/' && *p != '\0')
264 p++;
265 if (*p == '\0') {
266 cdcomppath = NULL;
267 } else {
268 *p++ = '\0';
269 cdcomppath = p;
270 }
271 return start;
272 }
273
274
275 static char *
findcwd(char * dir)276 findcwd(char *dir)
277 {
278 char *new;
279 char *p;
280 size_t len;
281
282 /*
283 * If our argument is NULL, we don't know the current directory
284 * any more because we traversed a symbolic link or something
285 * we couldn't stat().
286 */
287 if (dir == NULL || curdir == NULL)
288 return getpwd2();
289 len = strlen(dir);
290 cdcomppath = stalloc(len + 1);
291 memcpy(cdcomppath, dir, len + 1);
292 STARTSTACKSTR(new);
293 if (*dir != '/') {
294 STPUTS(curdir, new);
295 if (STTOPC(new) == '/')
296 STUNPUTC(new);
297 }
298 while ((p = getcomponent()) != NULL) {
299 if (equal(p, "..")) {
300 while (new > stackblock() && (STUNPUTC(new), *new) != '/');
301 } else if (*p != '\0' && ! equal(p, ".")) {
302 STPUTC('/', new);
303 STPUTS(p, new);
304 }
305 }
306 if (new == stackblock())
307 STPUTC('/', new);
308 STACKSTRNUL(new);
309 return stackblock();
310 }
311
312 /*
313 * Update curdir (the name of the current directory) in response to a
314 * cd command. We also call hashcd to let the routines in exec.c know
315 * that the current directory has changed.
316 */
317 static void
updatepwd(char * dir)318 updatepwd(char *dir)
319 {
320 hashcd(); /* update command hash table */
321
322 if (prevdir)
323 ckfree(prevdir);
324 prevdir = curdir;
325 curdir = dir ? savestr(dir) : NULL;
326 setvar("PWD", curdir, VEXPORT);
327 setvar("OLDPWD", prevdir, VEXPORT);
328 }
329
330 int
pwdcmd(int argc __unused,char ** argv __unused)331 pwdcmd(int argc __unused, char **argv __unused)
332 {
333 char *p;
334 int ch, phys;
335
336 phys = Pflag;
337 while ((ch = nextopt("LP")) != '\0') {
338 switch (ch) {
339 case 'L':
340 phys = 0;
341 break;
342 case 'P':
343 phys = 1;
344 break;
345 }
346 }
347
348 if (*argptr != NULL)
349 error("too many arguments");
350
351 if (!phys && getpwd()) {
352 out1str(curdir);
353 out1c('\n');
354 } else {
355 if ((p = getpwd2()) == NULL)
356 error(".: %s", strerror(errno));
357 out1str(p);
358 out1c('\n');
359 }
360
361 return 0;
362 }
363
364 /*
365 * Get the current directory and cache the result in curdir.
366 */
367 static char *
getpwd(void)368 getpwd(void)
369 {
370 char *p;
371
372 if (curdir)
373 return curdir;
374
375 p = getpwd2();
376 if (p != NULL)
377 curdir = savestr(p);
378
379 return curdir;
380 }
381
382 #define MAXPWD 256
383
384 /*
385 * Return the current directory.
386 */
387 static char *
getpwd2(void)388 getpwd2(void)
389 {
390 char *pwd;
391 int i;
392
393 for (i = MAXPWD;; i *= 2) {
394 pwd = stalloc(i);
395 if (getcwd(pwd, i) != NULL)
396 return pwd;
397 stunalloc(pwd);
398 if (errno != ERANGE)
399 break;
400 }
401
402 return NULL;
403 }
404
405 /*
406 * Initialize PWD in a new shell.
407 * If the shell is interactive, we need to warn if this fails.
408 */
409 void
pwd_init(int warn)410 pwd_init(int warn)
411 {
412 char *pwd;
413 struct stat stdot, stpwd;
414
415 pwd = lookupvar("PWD");
416 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 &&
417 stat(pwd, &stpwd) != -1 &&
418 stdot.st_dev == stpwd.st_dev &&
419 stdot.st_ino == stpwd.st_ino) {
420 if (curdir)
421 ckfree(curdir);
422 curdir = savestr(pwd);
423 }
424 if (getpwd() == NULL && warn)
425 out2fmt_flush("sh: cannot determine working directory\n");
426 setvar("PWD", curdir, VEXPORT);
427 }
428