freebsd-skq/bin/sh/cd.c
stefanf fe9202bf0f Split updatepwd() into two smaller functions. The first one, findpwd(),
computes the new path and the second one, updatepwd(), updates the variables
PWD, OLDPWD and the path used for the pwd builtin according to the new
directory.  For a logical directory change, chdir() is now called between
those two functions, no longer causing wrong values to be stored in PWD etc. if
it fails.

PR:	64990, 101316, 120571
2008-02-24 16:50:55 +00:00

392 lines
8.2 KiB
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("$FreeBSD$");
#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 char *findcwd(char *);
STATIC void updatepwd(char *);
STATIC char *getpwd2(char *, size_t);
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')
print = strcmp(p + 2, dest);
else
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 ((p = findcwd(badstat ? NULL : dest)) == NULL || chdir(p) < 0) {
INTON;
return (-1);
}
updatepwd(p);
INTON;
return (0);
}
STATIC int
cdphysical(char *dest)
{
char *p;
INTOFF;
if (chdir(dest) < 0 || (p = findcwd(NULL)) == NULL) {
INTON;
return (-1);
}
updatepwd(p);
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;
}
STATIC char *
findcwd(char *dir)
{
char *new;
char *p;
/*
* 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) {
p = stalloc(PATH_MAX);
return getpwd2(p, PATH_MAX);
}
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);
return stackblock();
}
/*
* 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 void
updatepwd(char *dir)
{
hashcd(); /* update command hash table */
if (prevdir)
ckfree(prevdir);
prevdir = curdir;
curdir = savestr(dir);
setvar("PWD", curdir, VEXPORT);
setvar("OLDPWD", prevdir, VEXPORT);
}
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;
}
/*
* Get the current directory and cache the result in curdir.
*/
char *
getpwd(void)
{
char buf[PATH_MAX];
char *p;
if (curdir)
return curdir;
p = getpwd2(buf, sizeof(buf));
if (p != NULL)
curdir = savestr(p);
return curdir;
}
/*
* Return the current directory.
*/
STATIC char *
getpwd2(char *buf, size_t size)
{
if (getcwd(buf, size) == 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) {
return pwd;
}
return NULL;
}
return buf;
}