[unix-history] / usr / src / bin / sh / cd.c

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)cd.c	5.4 (Berkeley) %G%";
#endif /* not lint */

/*
 * The cd and pwd commands.
 */

#include "shell.h"
#include "var.h"
#include "nodes.h"	/* for jobs.h */
#include "jobs.h"
#include "options.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "mystring.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>


#ifdef __STDC__
STATIC int docd(char *, int);
STATIC void updatepwd(char *);
STATIC void getpwd(void);
STATIC char *getcomponent(void);
#else
STATIC int docd();
STATIC void updatepwd();
STATIC void getpwd();
STATIC char *getcomponent();
#endif


char *curdir;			/* current working directory */
char *prevdir;			/* previous working directory */
STATIC char *cdcomppath;

int
cdcmd(argc, argv)  char **argv; {
	char *dest;
	char *path;
	char *p;
	struct stat statb;
	char *padvance();
	int print = 0;

	nextopt(nullstr);
	if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
		error("HOME not set");
	if (dest[0] == '-' && dest[1] == '\0') {
		dest = prevdir ? prevdir : curdir;
		print = 1;
	}
	if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL)
		path = nullstr;
	while ((p = padvance(&path, dest)) != NULL) {
		if (stat(p, &statb) >= 0
		 && (statb.st_mode & S_IFMT) == S_IFDIR) {
			if (!print) {
				/*
				 * XXX - rethink
				 */
				if (p[0] == '.' && p[1] == '/')
					p += 2;
				print = strcmp(p, dest);
			}
			if (docd(p, print) >= 0)
				return 0;

		}
	}
	error("can't cd to %s", dest);
}


/*
 * Actually do the chdir.  If the name refers to symbolic links, we
 * compute the actual directory name before doing the cd.  In an
 * interactive shell, print the directory name if "print" is nonzero
 * or if the name refers to a symbolic link.  We also print the name
 * if "/u/logname" was expanded in it, since this is similar to a
 * symbolic link.  (The check for this breaks if the user gives the
 * cd command some additional, unused arguments.)
 */

#if SYMLINKS == 0
STATIC int
docd(dest, print)
	char *dest;
	{
	INTOFF;
	if (chdir(dest) < 0) {
		INTON;
		return -1;
	}
	updatepwd(dest);
	INTON;
	if (print && iflag)
		out1fmt("%s\n", stackblock());
	return 0;
}

#else


STATIC int
docd(dest, print)
	char *dest;
	{
	register char *p;
	register char *q;
	char *symlink;
	char *component;
	struct stat statb;
	int first;
	int i;

	TRACE(("docd(\"%s\", %d) called\n", dest, print));

top:
	cdcomppath = dest;
	STARTSTACKSTR(p);
	if (*dest == '/') {
		STPUTC('/', p);
		cdcomppath++;
	}
	first = 1;
	while ((q = getcomponent()) != NULL) {
		if (q[0] == '\0' || q[0] == '.' && q[1] == '\0')
			continue;
		if (! first)
			STPUTC('/', p);
		first = 0;
		component = q;
		while (*q)
			STPUTC(*q++, p);
		if (equal(component, ".."))
			continue;
		STACKSTRNUL(p);
		if (lstat(stackblock(), &statb) < 0)
			error("lstat %s failed", stackblock());
		if ((statb.st_mode & S_IFMT) != S_IFLNK)
			continue;

		/* Hit a symbolic link.  We have to start all over again. */
		print = 1;
		STPUTC('\0', p);
		symlink = grabstackstr(p);
		i = (int)statb.st_size + 2;		/* 2 for '/' and '\0' */
		if (cdcomppath != NULL)
			i += strlen(cdcomppath);
		p = stalloc(i);
		if (readlink(symlink, p, (int)statb.st_size) < 0) {
			error("readlink %s failed", stackblock());
		}
		if (cdcomppath != NULL) {
			p[(int)statb.st_size] = '/';
			scopy(cdcomppath, p + (int)statb.st_size + 1);
		} else {
			p[(int)statb.st_size] = '\0';
		}
		if (p[0] != '/') {	/* relative path name */
			char *r;
			q = r = symlink;
			while (*q) {
				if (*q++ == '/')
					r = q;
			}
			*r = '\0';
			dest = stalloc(strlen(symlink) + strlen(p) + 1);
			scopy(symlink, dest);
			strcat(dest, p);
		} else {
			dest = p;
		}
		goto top;
	}
	STPUTC('\0', p);
	p = grabstackstr(p);
	INTOFF;
	if (chdir(p) < 0) {
		INTON;
		return -1;
	}
	updatepwd(p);
	INTON;
	if (print && iflag)
		out1fmt("%s\n", p);
	return 0;
}
#endif /* SYMLINKS */


/*
 * Get the next component of the path name pointed to by cdcomppath.
 * This routine overwrites the string pointed to by cdcomppath.
 */

STATIC char *
getcomponent() {
	register char *p;
	char *start;

	if ((p = cdcomppath) == NULL)
		return NULL;
	start = cdcomppath;
	while (*p != '/' && *p != '\0')
		p++;
	if (*p == '\0') {
		cdcomppath = NULL;
	} else {
		*p++ = '\0';
		cdcomppath = p;
	}
	return start;
}


/*
 * Update curdir (the name of the current directory) in response to a
 * cd command.  We also call hashcd to let the routines in exec.c know
 * that the current directory has changed.
 */

void hashcd();

STATIC void
updatepwd(dir)
	char *dir;
	{
	char *new;
	char *p;

	hashcd();				/* update command hash table */
	cdcomppath = stalloc(strlen(dir) + 1);
	scopy(dir, cdcomppath);
	STARTSTACKSTR(new);
	if (*dir != '/') {
		if (curdir == NULL)
			return;
		p = curdir;
		while (*p)
			STPUTC(*p++, new);
		if (p[-1] == '/')
			STUNPUTC(new);
	}
	while ((p = getcomponent()) != NULL) {
		if (equal(p, "..")) {
			while (new > stackblock() && (STUNPUTC(new), *new) != '/');
		} else if (*p != '\0' && ! equal(p, ".")) {
			STPUTC('/', new);
			while (*p)
				STPUTC(*p++, new);
		}
	}
	if (new == stackblock())
		STPUTC('/', new);
	STACKSTRNUL(new);
	INTOFF;
	if (prevdir)
		ckfree(prevdir);
	prevdir = curdir;
	curdir = savestr(stackblock());
	INTON;
}


int
pwdcmd(argc, argv)  char **argv; {
	getpwd();
	out1str(curdir);
	out1c('\n');
	return 0;
}


/*
 * Run /bin/pwd to find out what the current directory is.  We suppress
 * interrupts throughout most of this, but the user can still break out
 * of it by killing the pwd program.  If we already know the current
 * directory, this routine returns immediately.
 */

#define MAXPWD 256

STATIC void
getpwd() {
	char buf[MAXPWD];
	char *p;
	int i;
	int status;
	struct job *jp;
	int pip[2];

	if (curdir)
		return;
	INTOFF;
	if (pipe(pip) < 0)
		error("Pipe call failed");
	jp = makejob((union node *)NULL, 1);
	if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) {
		close(pip[0]);
		if (pip[1] != 1) {
			close(1);
			copyfd(pip[1], 1);
			close(pip[1]);
		}
		execl("/bin/pwd", "pwd", (char *)0);
		error("Cannot exec /bin/pwd");
	}
	close(pip[1]);
	pip[1] = -1;
	p = buf;
	while ((i = read(pip[0], p, buf + MAXPWD - p)) > 0
	     || i == -1 && errno == EINTR) {
		if (i > 0)
			p += i;
	}
	close(pip[0]);
	pip[0] = -1;
	status = waitforjob(jp);
	if (status != 0)
		error((char *)0);
	if (i < 0 || p == buf || p[-1] != '\n')
		error("pwd command failed");
	p[-1] = '\0';
	curdir = savestr(buf);
	INTON;
}
Commit	Line	Data
d003fee2 KB	1	/*-
	2	* Copyright (c) 1991 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Kenneth Almquist.
	7	*
	8	* %sccs.include.redist.c%
	9	*/
	10
	11	#ifndef lint
af4f2a31	12	static char sccsid[] = "@(#)cd.c 5.4 (Berkeley) %G%";
d003fee2 KB	13	#endif /* not lint */
	14
	15	/*
	16	* The cd and pwd commands.
	17	*/
	18
	19	#include "shell.h"
	20	#include "var.h"
	21	#include "nodes.h" /* for jobs.h */
	22	#include "jobs.h"
	23	#include "options.h"
	24	#include "output.h"
	25	#include "memalloc.h"
	26	#include "error.h"
	27	#include "mystring.h"
	28	#include <sys/types.h>
	29	#include <sys/stat.h>
	30	#include <errno.h>
	31
	32
	33	#ifdef __STDC__
	34	STATIC int docd(char *, int);
	35	STATIC void updatepwd(char *);
	36	STATIC void getpwd(void);
	37	STATIC char *getcomponent(void);
	38	#else
	39	STATIC int docd();
	40	STATIC void updatepwd();
	41	STATIC void getpwd();
	42	STATIC char *getcomponent();
	43	#endif
	44
	45
	46	char curdir; / current working directory */
af4f2a31	47	char prevdir; / previous working directory */
d003fee2 KB	48	STATIC char *cdcomppath;
d003fee2 KB	49
d003fee2 KB	50	int
	51	cdcmd(argc, argv) char **argv; {
	52	char *dest;
	53	char *path;
	54	char *p;
	55	struct stat statb;
	56	char *padvance();
af4f2a31	57	int print = 0;
d003fee2	58
ddba57cd MT	59	nextopt(nullstr);
ddba57cd MT	60	if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
d003fee2	61	error("HOME not set");
af4f2a31 MT	62	if (dest[0] == '-' && dest[1] == '\0') {
	63	dest = prevdir ? prevdir : curdir;
	64	print = 1;
	65	}
d003fee2 KB	66	if (*dest == '/' \|\| (path = bltinlookup("CDPATH", 1)) == NULL)
	67	path = nullstr;
	68	while ((p = padvance(&path, dest)) != NULL) {
	69	if (stat(p, &statb) >= 0
af4f2a31 MT	70	&& (statb.st_mode & S_IFMT) == S_IFDIR) {
	71	if (!print) {
	72	/*
	73	* XXX - rethink
	74	*/
	75	if (p[0] == '.' && p[1] == '/')
	76	p += 2;
	77	print = strcmp(p, dest);
	78	}
	79	if (docd(p, print) >= 0)
	80	return 0;
	81
	82	}
d003fee2 KB	83	}
	84	error("can't cd to %s", dest);
	85	}
	86
	87
	88	/*
	89	* Actually do the chdir. If the name refers to symbolic links, we
	90	* compute the actual directory name before doing the cd. In an
	91	* interactive shell, print the directory name if "print" is nonzero
	92	* or if the name refers to a symbolic link. We also print the name
	93	* if "/u/logname" was expanded in it, since this is similar to a
	94	* symbolic link. (The check for this breaks if the user gives the
	95	* cd command some additional, unused arguments.)
	96	*/
	97
	98	#if SYMLINKS == 0
	99	STATIC int
	100	docd(dest, print)
	101	char *dest;
	102	{
d003fee2 KB	103	INTOFF;
	104	if (chdir(dest) < 0) {
	105	INTON;
	106	return -1;
	107	}
	108	updatepwd(dest);
	109	INTON;
	110	if (print && iflag)
	111	out1fmt("%s\n", stackblock());
	112	return 0;
	113	}
	114
	115	#else
	116
	117
	118
	119	STATIC int
	120	docd(dest, print)
	121	char *dest;
	122	{
	123	register char *p;
	124	register char *q;
	125	char *symlink;
	126	char *component;
	127	struct stat statb;
	128	int first;
	129	int i;
	130
	131	TRACE(("docd(\"%s\", %d) called\n", dest, print));
d003fee2 KB	132
	133	top:
	134	cdcomppath = dest;
	135	STARTSTACKSTR(p);
	136	if (*dest == '/') {
	137	STPUTC('/', p);
	138	cdcomppath++;
	139	}
	140	first = 1;
	141	while ((q = getcomponent()) != NULL) {
	142	if (q[0] == '\0' \|\| q[0] == '.' && q[1] == '\0')
	143	continue;
	144	if (! first)
	145	STPUTC('/', p);
	146	first = 0;
	147	component = q;
	148	while (*q)
	149	STPUTC(*q++, p);
	150	if (equal(component, ".."))
	151	continue;
	152	STACKSTRNUL(p);
	153	if (lstat(stackblock(), &statb) < 0)
	154	error("lstat %s failed", stackblock());
	155	if ((statb.st_mode & S_IFMT) != S_IFLNK)
	156	continue;
	157
	158	/* Hit a symbolic link. We have to start all over again. */
	159	print = 1;
	160	STPUTC('\0', p);
	161	symlink = grabstackstr(p);
	162	i = (int)statb.st_size + 2; /* 2 for '/' and '\0' */
	163	if (cdcomppath != NULL)
	164	i += strlen(cdcomppath);
	165	p = stalloc(i);
	166	if (readlink(symlink, p, (int)statb.st_size) < 0) {
	167	error("readlink %s failed", stackblock());
	168	}
	169	if (cdcomppath != NULL) {
	170	p[(int)statb.st_size] = '/';
	171	scopy(cdcomppath, p + (int)statb.st_size + 1);
	172	} else {
	173	p[(int)statb.st_size] = '\0';
	174	}
	175	if (p[0] != '/') { /* relative path name */
	176	char *r;
	177	q = r = symlink;
	178	while (*q) {
	179	if (*q++ == '/')
	180	r = q;
	181	}
	182	*r = '\0';
	183	dest = stalloc(strlen(symlink) + strlen(p) + 1);
	184	scopy(symlink, dest);
	185	strcat(dest, p);
	186	} else {
	187	dest = p;
	188	}
	189	goto top;
	190	}
	191	STPUTC('\0', p);
	192	p = grabstackstr(p);
	193	INTOFF;
	194	if (chdir(p) < 0) {
	195	INTON;
196	return -1;
197	}
198	updatepwd(p);
199	INTON;
200	if (print && iflag)
201	out1fmt("%s\n", p);
202	return 0;
203	}
204	#endif /* SYMLINKS */
205
206
207
208	/*
209	* Get the next component of the path name pointed to by cdcomppath.
210	* This routine overwrites the string pointed to by cdcomppath.
211	*/
212
213	STATIC char *
214	getcomponent() {
215	register char *p;
216	char *start;
217
218	if ((p = cdcomppath) == NULL)
219	return NULL;
220	start = cdcomppath;
221	while (p != '/' && p != '\0')
222	p++;
223	if (*p == '\0') {
224	cdcomppath = NULL;
225	} else {
226	*p++ = '\0';
227	cdcomppath = p;
228	}
229	return start;
230	}
231
232
233
234	/*
235	* Update curdir (the name of the current directory) in response to a
236	* cd command. We also call hashcd to let the routines in exec.c know
237	* that the current directory has changed.
238	*/
239
240	void hashcd();
241
242	STATIC void
243	updatepwd(dir)
244	char *dir;
245	{
246	char *new;
247	char *p;
248
249	hashcd(); /* update command hash table */
250	cdcomppath = stalloc(strlen(dir) + 1);
251	scopy(dir, cdcomppath);
252	STARTSTACKSTR(new);
253	if (*dir != '/') {
254	if (curdir == NULL)
255	return;
256	p = curdir;
257	while (*p)
258	STPUTC(*p++, new);
259	if (p[-1] == '/')
260	STUNPUTC(new);
261	}
262	while ((p = getcomponent()) != NULL) {
263	if (equal(p, "..")) {
264	while (new > stackblock() && (STUNPUTC(new), *new) != '/');
265	} else if (*p != '\0' && ! equal(p, ".")) {
266	STPUTC('/', new);
267	while (*p)
268	STPUTC(*p++, new);
269	}
270	}
271	if (new == stackblock())
272	STPUTC('/', new);
273	STACKSTRNUL(new);
af4f2a31 MT	274	INTOFF;
	275	if (prevdir)
	276	ckfree(prevdir);
	277	prevdir = curdir;
d003fee2	278	curdir = savestr(stackblock());
af4f2a31	279	INTON;
d003fee2 KB	280	}
	281
	282
	283
	284	int
	285	pwdcmd(argc, argv) char **argv; {
	286	getpwd();
	287	out1str(curdir);
	288	out1c('\n');
	289	return 0;
	290	}
	291
	292
	293
	294	/*
	295	* Run /bin/pwd to find out what the current directory is. We suppress
	296	* interrupts throughout most of this, but the user can still break out
	297	* of it by killing the pwd program. If we already know the current
	298	* directory, this routine returns immediately.
	299	*/
	300
	301	#define MAXPWD 256
	302
	303	STATIC void
	304	getpwd() {
	305	char buf[MAXPWD];
	306	char *p;
	307	int i;
	308	int status;
	309	struct job *jp;
	310	int pip[2];
	311
	312	if (curdir)
	313	return;
	314	INTOFF;
	315	if (pipe(pip) < 0)
	316	error("Pipe call failed");
	317	jp = makejob((union node *)NULL, 1);
	318	if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) {
	319	close(pip[0]);
	320	if (pip[1] != 1) {
	321	close(1);
	322	copyfd(pip[1], 1);
	323	close(pip[1]);
	324	}
	325	execl("/bin/pwd", "pwd", (char *)0);
	326	error("Cannot exec /bin/pwd");
	327	}
	328	close(pip[1]);
	329	pip[1] = -1;
	330	p = buf;
	331	while ((i = read(pip[0], p, buf + MAXPWD - p)) > 0
	332	\|\| i == -1 && errno == EINTR) {
	333	if (i > 0)
	334	p += i;
	335	}
	336	close(pip[0]);
	337	pip[0] = -1;
	338	status = waitforjob(jp);
	339	if (status != 0)
	340	error((char *)0);
	341	if (i < 0 \|\| p == buf \|\| p[-1] != '\n')
	342	error("pwd command failed");
	343	p[-1] = '\0';
344	curdir = savestr(buf);
345	INTON;
346	}