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
35static 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
68static int cdlogical(char *);
69static int cdphysical(char *);
70static int docd(char *, int, int);
71static char *getcomponent(void);
72static char *findcwd(char *);
73static void updatepwd(char *);
74static char *getpwd(void);
75static char *getpwd2(void);
76
77static char *curdir = NULL;	/* current working directory */
78static char *prevdir;		/* previous working directory */
79static char *cdcomppath;
80
81int
82cdcmd(int argc, char **argv)
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	optreset = 1; optind = 1; opterr = 0; /* initialize getopt */
93	phys = Pflag;
94	while ((ch = getopt(argc, argv, "eLP")) != -1) {
95		switch (ch) {
96		case 'e':
97			getcwderr = 1;
98			break;
99		case 'L':
100			phys = 0;
101			break;
102		case 'P':
103			phys = 1;
104			break;
105		default:
106			error("unknown option: -%c", optopt);
107			break;
108		}
109	}
110	argc -= optind;
111	argv += optind;
112
113	if (argc > 1)
114		error("too many arguments");
115
116	if ((dest = *argv) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
117		error("HOME not set");
118	if (*dest == '\0')
119		dest = ".";
120	if (dest[0] == '-' && dest[1] == '\0') {
121		dest = prevdir ? prevdir : curdir;
122		if (dest)
123			print = 1;
124		else
125			dest = ".";
126	}
127	if (dest[0] == '/' ||
128	    (dest[0] == '.' && (dest[1] == '/' || dest[1] == '\0')) ||
129	    (dest[0] == '.' && dest[1] == '.' && (dest[2] == '/' || dest[2] == '\0')) ||
130	    (path = bltinlookup("CDPATH", 1)) == NULL)
131		path = nullstr;
132	while ((p = padvance(&path, dest)) != NULL) {
133		if (stat(p, &statb) < 0) {
134			if (errno != ENOENT)
135				errno1 = errno;
136		} else if (!S_ISDIR(statb.st_mode))
137			errno1 = ENOTDIR;
138		else {
139			if (!print) {
140				/*
141				 * XXX - rethink
142				 */
143				if (p[0] == '.' && p[1] == '/' && p[2] != '\0')
144					print = strcmp(p + 2, dest);
145				else
146					print = strcmp(p, dest);
147			}
148			rc = docd(p, print, phys);
149			if (rc >= 0)
150				return getcwderr ? rc : 0;
151			if (errno != ENOENT)
152				errno1 = errno;
153		}
154	}
155	error("%s: %s", dest, strerror(errno1));
156	/*NOTREACHED*/
157	return 0;
158}
159
160
161/*
162 * Actually change the directory.  In an interactive shell, print the
163 * directory name if "print" is nonzero.
164 */
165static int
166docd(char *dest, int print, int phys)
167{
168	int rc;
169
170	TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys));
171
172	/* If logical cd fails, fall back to physical. */
173	if ((phys || (rc = cdlogical(dest)) < 0) && (rc = cdphysical(dest)) < 0)
174		return (-1);
175
176	if (print && iflag && curdir)
177		out1fmt("%s\n", curdir);
178
179	return (rc);
180}
181
182static int
183cdlogical(char *dest)
184{
185	char *p;
186	char *q;
187	char *component;
188	struct stat statb;
189	int first;
190	int badstat;
191
192	/*
193	 *  Check each component of the path. If we find a symlink or
194	 *  something we can't stat, clear curdir to force a getcwd()
195	 *  next time we get the value of the current directory.
196	 */
197	badstat = 0;
198	cdcomppath = stalloc(strlen(dest) + 1);
199	scopy(dest, cdcomppath);
200	STARTSTACKSTR(p);
201	if (*dest == '/') {
202		STPUTC('/', p);
203		cdcomppath++;
204	}
205	first = 1;
206	while ((q = getcomponent()) != NULL) {
207		if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0'))
208			continue;
209		if (! first)
210			STPUTC('/', p);
211		first = 0;
212		component = q;
213		STPUTS(q, p);
214		if (equal(component, ".."))
215			continue;
216		STACKSTRNUL(p);
217		if (lstat(stackblock(), &statb) < 0) {
218			badstat = 1;
219			break;
220		}
221	}
222
223	INTOFF;
224	if ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) {
225		INTON;
226		return (-1);
227	}
228	updatepwd(p);
229	INTON;
230	return (0);
231}
232
233static int
234cdphysical(char *dest)
235{
236	char *p;
237	int rc = 0;
238
239	INTOFF;
240	if (chdir(dest) < 0) {
241		INTON;
242		return (-1);
243	}
244	p = findcwd(NULL);
245	if (p == NULL) {
246		warning("warning: failed to get name of current directory");
247		rc = 1;
248	}
249	updatepwd(p);
250	INTON;
251	return (rc);
252}
253
254/*
255 * Get the next component of the path name pointed to by cdcomppath.
256 * This routine overwrites the string pointed to by cdcomppath.
257 */
258static char *
259getcomponent(void)
260{
261	char *p;
262	char *start;
263
264	if ((p = cdcomppath) == NULL)
265		return NULL;
266	start = cdcomppath;
267	while (*p != '/' && *p != '\0')
268		p++;
269	if (*p == '\0') {
270		cdcomppath = NULL;
271	} else {
272		*p++ = '\0';
273		cdcomppath = p;
274	}
275	return start;
276}
277
278
279static char *
280findcwd(char *dir)
281{
282	char *new;
283	char *p;
284
285	/*
286	 * If our argument is NULL, we don't know the current directory
287	 * any more because we traversed a symbolic link or something
288	 * we couldn't stat().
289	 */
290	if (dir == NULL || curdir == NULL)
291		return getpwd2();
292	cdcomppath = stalloc(strlen(dir) + 1);
293	scopy(dir, cdcomppath);
294	STARTSTACKSTR(new);
295	if (*dir != '/') {
296		STPUTS(curdir, new);
297		if (STTOPC(new) == '/')
298			STUNPUTC(new);
299	}
300	while ((p = getcomponent()) != NULL) {
301		if (equal(p, "..")) {
302			while (new > stackblock() && (STUNPUTC(new), *new) != '/');
303		} else if (*p != '\0' && ! equal(p, ".")) {
304			STPUTC('/', new);
305			STPUTS(p, new);
306		}
307	}
308	if (new == stackblock())
309		STPUTC('/', new);
310	STACKSTRNUL(new);
311	return stackblock();
312}
313
314/*
315 * Update curdir (the name of the current directory) in response to a
316 * cd command.  We also call hashcd to let the routines in exec.c know
317 * that the current directory has changed.
318 */
319static void
320updatepwd(char *dir)
321{
322	hashcd();				/* update command hash table */
323
324	if (prevdir)
325		ckfree(prevdir);
326	prevdir = curdir;
327	curdir = dir ? savestr(dir) : NULL;
328	setvar("PWD", curdir, VEXPORT);
329	setvar("OLDPWD", prevdir, VEXPORT);
330}
331
332int
333pwdcmd(int argc, char **argv)
334{
335	char *p;
336	int ch, phys;
337
338	optreset = 1; optind = 1; opterr = 0; /* initialize getopt */
339	phys = Pflag;
340	while ((ch = getopt(argc, argv, "LP")) != -1) {
341		switch (ch) {
342		case 'L':
343			phys = 0;
344			break;
345		case 'P':
346			phys = 1;
347			break;
348		default:
349			error("unknown option: -%c", optopt);
350			break;
351		}
352	}
353	argc -= optind;
354	argv += optind;
355
356	if (argc != 0)
357		error("too many arguments");
358
359	if (!phys && getpwd()) {
360		out1str(curdir);
361		out1c('\n');
362	} else {
363		if ((p = getpwd2()) == NULL)
364			error(".: %s", strerror(errno));
365		out1str(p);
366		out1c('\n');
367	}
368
369	return 0;
370}
371
372/*
373 * Get the current directory and cache the result in curdir.
374 */
375static char *
376getpwd(void)
377{
378	char *p;
379
380	if (curdir)
381		return curdir;
382
383	p = getpwd2();
384	if (p != NULL)
385		curdir = savestr(p);
386
387	return curdir;
388}
389
390#define MAXPWD 256
391
392/*
393 * Return the current directory.
394 */
395static char *
396getpwd2(void)
397{
398	char *pwd;
399	int i;
400
401	for (i = MAXPWD;; i *= 2) {
402		pwd = stalloc(i);
403		if (getcwd(pwd, i) != NULL)
404			return pwd;
405		stunalloc(pwd);
406		if (errno != ERANGE)
407			break;
408	}
409
410	return NULL;
411}
412
413/*
414 * Initialize PWD in a new shell.
415 * If the shell is interactive, we need to warn if this fails.
416 */
417void
418pwd_init(int warn)
419{
420	char *pwd;
421	struct stat stdot, stpwd;
422
423	pwd = lookupvar("PWD");
424	if (pwd && *pwd == '/' && stat(".", &stdot) != -1 &&
425	    stat(pwd, &stpwd) != -1 &&
426	    stdot.st_dev == stpwd.st_dev &&
427	    stdot.st_ino == stpwd.st_ino) {
428		if (curdir)
429			ckfree(curdir);
430		curdir = savestr(pwd);
431	}
432	if (getpwd() == NULL && warn)
433		out2fmt_flush("sh: cannot determine working directory\n");
434	setvar("PWD", curdir, VEXPORT);
435}
436