cd.c revision 36150 
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. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38#if 0
39static char sccsid[] = "@(#)cd.c	8.2 (Berkeley) 5/4/95";
40#endif
41static const char rcsid[] =
42	"$Id$";
43#endif /* not lint */
44
45#include <sys/types.h>
46#include <sys/stat.h>
47#include <stdlib.h>
48#include <string.h>
49#include <unistd.h>
50#include <errno.h>
51
52/*
53 * The cd and pwd commands.
54 */
55
56#include "shell.h"
57#include "var.h"
58#include "nodes.h"	/* for jobs.h */
59#include "jobs.h"
60#include "options.h"
61#include "output.h"
62#include "memalloc.h"
63#include "error.h"
64#include "exec.h"
65#include "redir.h"
66#include "mystring.h"
67#include "show.h"
68#include "cd.h"
69
70STATIC int docd __P((char *, int));
71STATIC char *getcomponent __P((void));
72STATIC void updatepwd __P((char *));
73
74char *curdir = NULL;		/* current working directory */
75char *prevdir;			/* previous working directory */
76STATIC char *cdcomppath;
77
78int
79cdcmd(argc, argv)
80	int argc __unused;
81	char **argv __unused;
82{
83	char *dest;
84	char *path;
85	char *p;
86	struct stat statb;
87	int print = 0;
88
89	nextopt(nullstr);
90	if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
91		error("HOME not set");
92	if (*dest == '\0')
93		dest = ".";
94	if (dest[0] == '-' && dest[1] == '\0') {
95		dest = prevdir ? prevdir : curdir;
96		if (dest)
97			print = 1;
98		else
99			dest = ".";
100	}
101	if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL)
102		path = nullstr;
103	while ((p = padvance(&path, dest)) != NULL) {
104		if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
105			if (!print) {
106				/*
107				 * XXX - rethink
108				 */
109				if (p[0] == '.' && p[1] == '/')
110					p += 2;
111				print = strcmp(p, dest);
112			}
113			if (docd(p, print) >= 0)
114				return 0;
115
116		}
117	}
118	error("can't cd to %s", dest);
119	/*NOTREACHED*/
120	return 0;
121}
122
123
124/*
125 * Actually do the chdir.  In an interactive shell, print the
126 * directory name if "print" is nonzero.
127 */
128STATIC int
129docd(dest, print)
130	char *dest;
131	int print;
132{
133
134	TRACE(("docd(\"%s\", %d) called\n", dest, print));
135	INTOFF;
136	updatepwd(dest);
137	if (chdir(stackblock()) < 0) {
138		INTON;
139		return -1;
140	}
141	hashcd();				/* update command hash table */
142	if (prevdir)
143		ckfree(prevdir);
144	prevdir = curdir;
145	curdir = savestr(stackblock());
146	INTON;
147	if (print && iflag)
148		out1fmt("%s\n", stackblock());
149	return 0;
150}
151
152
153/*
154 * Get the next component of the path name pointed to by cdcomppath.
155 * This routine overwrites the string pointed to by cdcomppath.
156 */
157STATIC char *
158getcomponent()
159{
160	char *p;
161	char *start;
162
163	if ((p = cdcomppath) == NULL)
164		return NULL;
165	start = cdcomppath;
166	while (*p != '/' && *p != '\0')
167		p++;
168	if (*p == '\0') {
169		cdcomppath = NULL;
170	} else {
171		*p++ = '\0';
172		cdcomppath = p;
173	}
174	return start;
175}
176
177
178/*
179 * Determine the new working directory, but don't actually enforce
180 * any changes.
181 */
182STATIC void
183updatepwd(dir)
184	char *dir;
185{
186	char *new;
187	char *p;
188
189	cdcomppath = stalloc(strlen(dir) + 1);
190	scopy(dir, cdcomppath);
191	STARTSTACKSTR(new);
192	if (*dir != '/') {
193		if (curdir == NULL)
194			return;
195		p = curdir;
196		while (*p)
197			STPUTC(*p++, new);
198		if (p[-1] == '/')
199			STUNPUTC(new);
200	}
201	while ((p = getcomponent()) != NULL) {
202		if (equal(p, "..")) {
203			while (new > stackblock() && (STUNPUTC(new), *new) != '/');
204		} else if (*p != '\0' && ! equal(p, ".")) {
205			STPUTC('/', new);
206			while (*p)
207				STPUTC(*p++, new);
208		}
209	}
210	if (new == stackblock())
211		STPUTC('/', new);
212	STACKSTRNUL(new);
213}
214
215
216int
217pwdcmd(argc, argv)
218	int argc __unused;
219	char **argv __unused;
220{
221	if (!getpwd())
222		error("getcwd() failed: %s", strerror(errno));
223	out1str(curdir);
224	out1c('\n');
225	return 0;
226}
227
228
229/*
230 * Find out what the current directory is. If we already know the current
231 * directory, this routine returns immediately.
232 */
233char *
234getpwd()
235{
236	if (curdir)
237		return (curdir);
238	return ((curdir = getcwd(NULL, 0)));
239}
240