FreeBSD-5.3/bin/sh/cd.c
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
#if 0
static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/bin/sh/cd.c,v 1.34 2004/04/06 20:06:51 markm Exp $");
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <limits.h>
/*
* 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 "exec.h"
#include "redir.h"
#include "mystring.h"
#include "show.h"
#include "cd.h"
STATIC int cdlogical(char *);
STATIC int cdphysical(char *);
STATIC int docd(char *, int, int);
STATIC char *getcomponent(void);
STATIC int updatepwd(char *);
STATIC char *curdir = NULL; /* current working directory */
STATIC char *prevdir; /* previous working directory */
STATIC char *cdcomppath;
int
cdcmd(int argc, char **argv)
{
char *dest;
char *path;
char *p;
struct stat statb;
int ch, phys, print = 0;
optreset = 1; optind = 1; opterr = 0; /* initialize getopt */
phys = Pflag;
while ((ch = getopt(argc, argv, "LP")) != -1) {
switch (ch) {
case 'L':
phys = 0;
break;
case 'P':
phys = 1;
break;
default:
error("unknown option: -%c", optopt);
break;
}
}
argc -= optind;
argv += optind;
if (argc > 1)
error("too many arguments");
if ((dest = *argv) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
error("HOME not set");
if (*dest == '\0')
dest = ".";
if (dest[0] == '-' && dest[1] == '\0') {
dest = prevdir ? prevdir : curdir;
if (dest)
print = 1;
else
dest = ".";
}
if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL)
path = nullstr;
while ((p = padvance(&path, dest)) != NULL) {
if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
if (!print) {
/*
* XXX - rethink
*/
if (p[0] == '.' && p[1] == '/' && p[2] != '\0')
p += 2;
print = strcmp(p, dest);
}
if (docd(p, print, phys) >= 0)
return 0;
}
}
error("can't cd to %s", dest);
/*NOTREACHED*/
return 0;
}
/*
* Actually change the directory. In an interactive shell, print the
* directory name if "print" is nonzero.
*/
STATIC int
docd(char *dest, int print, int phys)
{
TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys));
/* If logical cd fails, fall back to physical. */
if ((phys || cdlogical(dest) < 0) && cdphysical(dest) < 0)
return (-1);
if (print && iflag && curdir)
out1fmt("%s\n", curdir);
return 0;
}
STATIC int
cdlogical(char *dest)
{
char *p;
char *q;
char *component;
struct stat statb;
int first;
int badstat;
/*
* Check each component of the path. If we find a symlink or
* something we can't stat, clear curdir to force a getcwd()
* next time we get the value of the current directory.
*/
badstat = 0;
cdcomppath = stalloc(strlen(dest) + 1);
scopy(dest, cdcomppath);
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) {
badstat = 1;
break;
}
}
INTOFF;
if (updatepwd(badstat ? NULL : dest) < 0 || chdir(curdir) < 0) {
INTON;
return (-1);
}
INTON;
return (0);
}
STATIC int
cdphysical(char *dest)
{
INTOFF;
if (chdir(dest) < 0 || updatepwd(NULL) < 0) {
INTON;
return (-1);
}
INTON;
return (0);
}
/*
* Get the next component of the path name pointed to by cdcomppath.
* This routine overwrites the string pointed to by cdcomppath.
*/
STATIC char *
getcomponent(void)
{
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.
*/
STATIC int
updatepwd(char *dir)
{
char *new;
char *p;
hashcd(); /* update command hash table */
/*
* If our argument is NULL, we don't know the current directory
* any more because we traversed a symbolic link or something
* we couldn't stat().
*/
if (dir == NULL || curdir == NULL) {
if (prevdir)
ckfree(prevdir);
INTOFF;
prevdir = curdir;
curdir = NULL;
if (getpwd() == NULL) {
INTON;
return (-1);
}
setvar("PWD", curdir, VEXPORT);
setvar("OLDPWD", prevdir, VEXPORT);
INTON;
return (0);
}
cdcomppath = stalloc(strlen(dir) + 1);
scopy(dir, cdcomppath);
STARTSTACKSTR(new);
if (*dir != '/') {
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());
setvar("PWD", curdir, VEXPORT);
setvar("OLDPWD", prevdir, VEXPORT);
INTON;
return (0);
}
int
pwdcmd(int argc, char **argv)
{
char buf[PATH_MAX];
int ch, phys;
optreset = 1; optind = 1; opterr = 0; /* initialize getopt */
phys = Pflag;
while ((ch = getopt(argc, argv, "LP")) != -1) {
switch (ch) {
case 'L':
phys = 0;
break;
case 'P':
phys = 1;
break;
default:
error("unknown option: -%c", optopt);
break;
}
}
argc -= optind;
argv += optind;
if (argc != 0)
error("too many arguments");
if (!phys && getpwd()) {
out1str(curdir);
out1c('\n');
} else {
if (getcwd(buf, sizeof(buf)) == NULL)
error(".: %s", strerror(errno));
out1str(buf);
out1c('\n');
}
return 0;
}
/*
* Find out what the current directory is. If we already know the current
* directory, this routine returns immediately.
*/
char *
getpwd(void)
{
char buf[PATH_MAX];
if (curdir)
return curdir;
if (getcwd(buf, sizeof(buf)) == NULL) {
char *pwd = getenv("PWD");
struct stat stdot, stpwd;
if (pwd && *pwd == '/' && stat(".", &stdot) != -1 &&
stat(pwd, &stpwd) != -1 &&
stdot.st_dev == stpwd.st_dev &&
stdot.st_ino == stpwd.st_ino) {
curdir = savestr(pwd);
return curdir;
}
return NULL;
}
curdir = savestr(buf);
return curdir;
}