This file is cd.def, from which is created cd.c. It implements the
builtins "cd" and "pwd" in Bash.
Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
Bash is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
with Bash; see the file COPYING. If not, write to the Free Software
Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
$PRODUCES cd.c
#include <config.h>
#if defined (HAVE_UNISTD_H)
# ifdef _MINIX
# include <sys/types.h>
# endif
# include <unistd.h>
#endif
#include "../bashtypes.h"
#include "posixdir.h"
#include "posixstat.h"
#ifndef _MINIX
#include <sys/param.h>
#endif
#include <stdio.h>
#include "../bashansi.h"
#include <errno.h>
#include <tilde/tilde.h>
#include "../shell.h"
#include "../flags.h"
#include "maxpath.h"
#include "common.h"
#include "bashgetopt.h"
#if !defined (errno)
extern int errno;
#endif /* !errno */
extern int posixly_correct;
extern int array_needs_making;
extern char *bash_getcwd_errstr;
static int bindpwd __P((int));
static int change_to_directory __P((char *, int));
static char *cdspell __P((char *));
/* Change this to 1 to get cd spelling correction by default. */
int cdspelling = 0;
int cdable_vars;
$BUILTIN cd
$FUNCTION cd_builtin
$SHORT_DOC cd [-L|-P] [dir]
Change the current directory to DIR. The variable $HOME is the
default DIR. The variable CDPATH defines the search path for
the directory containing DIR. Alternative directory names in CDPATH
are separated by a colon (:). A null directory name is the same as
the current directory, i.e. `.'. If DIR begins with a slash (/),
then CDPATH is not used. If the directory is not found, and the
shell option `cdable_vars' is set, then try the word as a variable
name. If that variable has a value, then cd to the value of that
variable. The -P option says to use the physical directory structure
instead of following symbolic links; the -L option forces symbolic links
to be followed.
$END
static int
bindpwd (no_symlinks)
int no_symlinks;
{
char *dirname, *pwdvar;
int old_anm;
SHELL_VAR *tvar;
#define tcwd the_current_working_directory
dirname = tcwd ? (no_symlinks ? sh_physpath (tcwd, 0) : tcwd)
: get_working_directory ("cd");
#undef tcwd
old_anm = array_needs_making;
pwdvar = get_string_value ("PWD");
tvar = bind_variable ("OLDPWD", pwdvar);
if (old_anm == 0 && array_needs_making && exported_p (tvar))
{
update_export_env_inplace ("OLDPWD=", 7, pwdvar);
array_needs_making = 0;
}
tvar = bind_variable ("PWD", dirname);
if (old_anm == 0 && array_needs_making && exported_p (tvar))
{
update_export_env_inplace ("PWD=", 4, dirname);
array_needs_making = 0;
}
if (dirname && dirname != the_current_working_directory)
free (dirname);
return (EXECUTION_SUCCESS);
}
/* Call get_working_directory to reset the value of
the_current_working_directory () */
static char *
resetpwd ()
{
char *tdir;
FREE (the_current_working_directory);
the_current_working_directory = (char *)NULL;
tdir = get_working_directory ("cd");
return (tdir);
}
#define LCD_DOVARS 0x001
#define LCD_DOSPELL 0x002
#define LCD_PRINTPATH 0x004
#define LCD_FREEDIRNAME 0x010
/* This builtin is ultimately the way that all user-visible commands should
change the current working directory. It is called by cd_to_string (),
so the programming interface is simple, and it handles errors and
restrictions properly. */
int
cd_builtin (list)
WORD_LIST *list;
{
char *dirname, *cdpath, *path, *temp;
int path_index, no_symlinks, opt, lflag;
#if defined (RESTRICTED_SHELL)
if (restricted)
{
sh_restricted ((char *)NULL);
return (EXECUTION_FAILURE);
}
#endif /* RESTRICTED_SHELL */
no_symlinks = no_symbolic_links;
reset_internal_getopt ();
while ((opt = internal_getopt (list, "LP")) != -1)
{
switch (opt)
{
case 'P':
no_symlinks = 1;
break;
case 'L':
no_symlinks = 0;
break;
default:
builtin_usage ();
return (EXECUTION_FAILURE);
}
}
list = loptend;
lflag = (cdable_vars ? LCD_DOVARS : 0) |
((interactive && cdspelling) ? LCD_DOSPELL : 0);
if (list == 0)
{
/* `cd' without arguments is equivalent to `cd $HOME' */
dirname = get_string_value ("HOME");
if (dirname == 0)
{
builtin_error ("HOME not set");
return (EXECUTION_FAILURE);
}
lflag = 0;
}
else if (list->word->word[0] == '-' && list->word->word[1] == '\0')
{
/* This is `cd -', equivalent to `cd $OLDPWD' */
dirname = get_string_value ("OLDPWD");
if (dirname == 0)
{
builtin_error ("OLDPWD not set");
return (EXECUTION_FAILURE);
}
lflag = interactive ? LCD_PRINTPATH : 0;
}
else if (absolute_pathname (list->word->word))
dirname = list->word->word;
else if (cdpath = get_string_value ("CDPATH"))
{
dirname = list->word->word;
/* Find directory in $CDPATH. */
path_index = 0;
while (path = extract_colon_unit (cdpath, &path_index))
{
/* OPT is 1 if the path element is non-empty */
opt = path[0] != '\0';
temp = sh_makepath (path, dirname, MP_DOTILDE);
free (path);
if (change_to_directory (temp, no_symlinks))
{
/* POSIX.2 says that if a nonempty directory from CDPATH
is used to find the directory to change to, the new
directory name is echoed to stdout, whether or not
the shell is interactive. */
if (opt)
printf ("%s\n", no_symlinks ? temp : the_current_working_directory);
free (temp);
/* Posix.2 says that after using CDPATH, the resultant
value of $PWD will not contain `.' or `..'. */
return (bindpwd (posixly_correct || no_symlinks));
}
else
free (temp);
}
/* POSIX.2 says that if `.' does not appear in $CDPATH, we don't
try the current directory, so we just punt now with an error
message if POSIXLY_CORRECT is non-zero. The check for cdpath[0]
is so we don't mistakenly treat a CDPATH value of "" as not
specifying the current directory. */
if (posixly_correct && cdpath[0])
{
builtin_error ("%s: %s", dirname, strerror (ENOENT));
return (EXECUTION_FAILURE);
}
}
else
dirname = list->word->word;
/* When we get here, DIRNAME is the directory to change to. If we
chdir successfully, just return. */
if (change_to_directory (dirname, no_symlinks))
{
if (lflag & LCD_PRINTPATH)
printf ("%s\n", dirname);
return (bindpwd (no_symlinks));
}
/* If the user requests it, then perhaps this is the name of
a shell variable, whose value contains the directory to
change to. */
if (lflag & LCD_DOVARS)
{
temp = get_string_value (dirname);
if (temp && change_to_directory (temp, no_symlinks))
{
printf ("%s\n", temp);
return (bindpwd (no_symlinks));
}
}
/* If the user requests it, try to find a directory name similar in
spelling to the one requested, in case the user made a simple
typo. This is similar to the UNIX 8th and 9th Edition shells. */
if (lflag & LCD_DOSPELL)
{
temp = cdspell (dirname);
if (temp && change_to_directory (temp, no_symlinks))
{
printf ("%s\n", temp);
return (bindpwd (no_symlinks));
}
else
FREE (temp);
}
builtin_error ("%s: %s", dirname, strerror (errno));
return (EXECUTION_FAILURE);
}
$BUILTIN pwd
$FUNCTION pwd_builtin
$SHORT_DOC pwd [-PL]
Print the current working directory. With the -P option, pwd prints
the physical directory, without any symbolic links; the -L option
makes pwd follow symbolic links.
$END
/* Non-zero means that pwd always prints the physical directory, without
symbolic links. */
static int verbatim_pwd;
/* Print the name of the current working directory. */
int
pwd_builtin (list)
WORD_LIST *list;
{
char *directory;
int opt;
verbatim_pwd = no_symbolic_links;
reset_internal_getopt ();
while ((opt = internal_getopt (list, "LP")) != -1)
{
switch (opt)
{
case 'P':
verbatim_pwd = 1;
break;
case 'L':
verbatim_pwd = 0;
break;
default:
builtin_usage ();
return (EXECUTION_FAILURE);
}
}
list = loptend;
#define tcwd the_current_working_directory
directory = tcwd ? (verbatim_pwd ? sh_physpath (tcwd, 0) : tcwd)
: get_working_directory ("pwd");
#undef tcwd
if (directory)
{
printf ("%s\n", directory);
if (directory != the_current_working_directory)
free (directory);
fflush (stdout);
if (ferror (stdout))
{
builtin_error ("write error: %s", strerror (errno));
return (EXECUTION_FAILURE);
}
return (EXECUTION_SUCCESS);
}
else
return (EXECUTION_FAILURE);
}
/* Do the work of changing to the directory NEWDIR. Handle symbolic
link following, etc. This function *must* return with
the_current_working_directory either set to NULL (in which case
getcwd() will eventually be called), or set to a string corresponding
to the working directory. Return 1 on success, 0 on failure. */
static int
change_to_directory (newdir, nolinks)
char *newdir;
int nolinks;
{
char *t, *tdir;
int err, canon_failed;
tdir = (char *)NULL;
if (the_current_working_directory == 0)
{
t = get_working_directory ("chdir");
FREE (t);
}
t = make_absolute (newdir, the_current_working_directory);
/* TDIR is either the canonicalized absolute pathname of NEWDIR
(nolinks == 0) or the absolute physical pathname of NEWDIR
(nolinks != 0). */
tdir = nolinks ? sh_physpath (t, 0)
: sh_canonpath (t, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);
/* Use the canonicalized version of NEWDIR, or, if canonicalization
failed, use the non-canonical form. */
canon_failed = 0;
if (tdir && *tdir)
free (t);
else
{
FREE (tdir);
tdir = t;
canon_failed = 1;
}
/* In POSIX mode, if we're resolving symlinks logically and sh_canonpath
returns NULL (because it checks the path, it will return NULL if the
resolved path doesn't exist), fail immediately. */
if (posixly_correct && nolinks == 0 && canon_failed)
{
errno = ENOENT;
return (0);
}
/* If the chdir succeeds, update the_current_working_directory. */
if (chdir (nolinks ? newdir : tdir) == 0)
{
/* If canonicalization failed, but the chdir succeeded, reset the
shell's idea of the_current_working_directory. */
if (canon_failed)
resetpwd ();
else
{
FREE (the_current_working_directory);
the_current_working_directory = tdir;
}
return (1);
}
/* We failed to change to the appropriate directory name. If we tried
what the user passed (nolinks != 0), punt now. */
if (nolinks)
return (0);
err = errno;
free (tdir);
/* We're not in physical mode (nolinks == 0), but we failed to change to
the canonicalized directory name (TDIR). Try what the user passed
verbatim. If we succeed, reinitialize the_current_working_directory. */
if (chdir (newdir) == 0)
{
tdir = resetpwd ();
FREE (tdir);
return (1);
}
else
{
errno = err;
return (0);
}
}
/* Code for cd spelling correction. Original patch submitted by
Neil Russel (caret@c-side.com). */
static char *
cdspell (dirname)
char *dirname;
{
int n;
char *guess;
n = (strlen (dirname) * 3 + 1) / 2 + 1;
guess = (char *)xmalloc (n);
switch (spname (dirname, guess))
{
case -1:
default:
free (guess);
return (char *)NULL;
case 0:
case 1:
return guess;
}
}