=head1 NAME
-getcwd - get pathname of current working directory
+Cwd - get pathname of current working directory
=head1 SYNOPSIS
$dir = getcwd;
use Cwd;
+ $dir = fastcwd;
+
+ use Cwd;
$dir = fastgetcwd;
use Cwd 'chdir';
chdir "/tmp";
print $ENV{'PWD'};
+ use Cwd 'abs_path'; # aka realpath()
+ print abs_path($ENV{'PWD'});
+
+ use Cwd 'fast_abs_path';
+ print fast_abs_path($ENV{'PWD'});
+
=head1 DESCRIPTION
+This module provides functions for determining the pathname of the
+current working directory. By default, it exports the functions
+cwd(), getcwd(), fastcwd(), and fastgetcwd() into the caller's
+namespace. Each of these functions are called without arguments and
+return the absolute path of the current working directory. It is
+recommended that cwd (or another *cwd() function) be used in I<all>
+code to ensure portability.
+
+The cwd() is the most natural and safe form for the current
+architecture. For most systems it is identical to `pwd` (but without
+the trailing line terminator).
+
The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions
in Perl.
The fastcwd() function looks the same as getcwd(), but runs faster.
-It's also more dangerous because you might conceivably chdir() out of a
-directory that you can't chdir() back into.
-
-The cwd() function looks the same as getcwd and fastgetcwd but is
-implemented using the most natural and safe form for the current
-architecture. For most systems it is identical to `pwd` (but without
-the trailing line terminator). It is recommended that cwd (or another
-*cwd() function) is used in I<all> code to ensure portability.
+It's also more dangerous because it might conceivably chdir() you out
+of a directory that it can't chdir() you back into. If fastcwd
+encounters a problem it will return undef but will probably leave you
+in a different directory. For a measure of extra security, if
+everything appears to have worked, the fastcwd() function will check
+that it leaves you in the same directory that it started in. If it has
+changed it will C<die> with the message "Unstable directory path,
+current directory changed unexpectedly". That should never happen.
+
+The fastgetcwd() function is provided as a synonym for cwd().
+
+The abs_path() function takes a single argument and returns the
+absolute pathname for that argument. It uses the same algorithm as
+getcwd(). (Actually, getcwd() is abs_path(".")) Symbolic links and
+relative-path components ("." and "..") are resolved to return the
+canonical pathname, just like realpath(3). This function is also
+callable as realpath().
+
+The fast_abs_path() function looks the same as abs_path() but runs
+faster and, like fastcwd(), is more dangerous.
If you ask to override your chdir() built-in function, then your PWD
environment variable will be kept up to date. (See
=cut
-## use strict;
+use strict;
use Carp;
-$VERSION = '2.00';
+our $VERSION = '2.04';
-require Exporter;
-@ISA = qw(Exporter);
-@EXPORT = qw(cwd getcwd fastcwd fastgetcwd);
-@EXPORT_OK = qw(chdir abs_path fast_abs_path);
+use base qw/ Exporter /;
+our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd);
+our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath);
+eval {
+ require XSLoader;
+ XSLoader::load('Cwd');
+};
# The 'natural and safe form' for UNIX (pwd may be setuid root)
sub _backtick_pwd {
- my $cwd;
- chop($cwd = `pwd`);
+ my $cwd = `pwd`;
+ # `pwd` may fail e.g. if the disk is full
+ chomp($cwd) if defined $cwd;
$cwd;
}
# Since some ports may predefine cwd internally (e.g., NT)
# we take care not to override an existing definition for cwd().
-*cwd = \&_backtick_pwd unless defined &cwd;
+unless(defined &cwd) {
+ # The pwd command is not available in some chroot(2)'ed environments
+ if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) {
+ *cwd = \&_backtick_pwd;
+ }
+ else {
+ *cwd = \&getcwd;
+ }
+}
+# set a reasonable (and very safe) default for fastgetcwd, in case it
+# isn't redefined later (20001212 rspier)
+*fastgetcwd = \&cwd;
# By Brandon S. Allbery
#
sub getcwd
{
- my($dotdots, $cwd, @pst, @cst, $dir, @tst);
-
- unless (@cst = stat('.'))
- {
- warn "stat(.): $!";
- return '';
- }
- $cwd = '';
- $dotdots = '';
- do
- {
- $dotdots .= '/' if $dotdots;
- $dotdots .= '..';
- @pst = @cst;
- unless (opendir(PARENT, $dotdots))
- {
- warn "opendir($dotdots): $!";
- return '';
- }
- unless (@cst = stat($dotdots))
- {
- warn "stat($dotdots): $!";
- closedir(PARENT);
- return '';
- }
- if ($pst[0] == $cst[0] && $pst[1] == $cst[1])
- {
- $dir = '';
- }
- else
- {
- do
- {
- unless (defined ($dir = readdir(PARENT)))
- {
- warn "readdir($dotdots): $!";
- closedir(PARENT);
- return '';
- }
- unless (@tst = lstat("$dotdots/$dir"))
- {
- # warn "lstat($dotdots/$dir): $!";
- # Just because you can't lstat this directory
- # doesn't mean you'll never find the right one.
- # closedir(PARENT);
- # return '';
- }
- }
- while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] ||
- $tst[1] != $pst[1]);
- }
- $cwd = "$dir/$cwd";
- closedir(PARENT);
- } while ($dir);
- chop($cwd) unless $cwd eq '/'; # drop the trailing /
- $cwd;
+ abs_path('.');
}
-
-
-# By John Bazik
-#
-# Usage: $cwd = &fastcwd;
-#
-# This is a faster version of getcwd. It's also more dangerous because
-# you might chdir out of a directory that you can't chdir back into.
-
-sub fastcwd {
- my($odev, $oino, $cdev, $cino, $tdev, $tino);
- my(@path, $path);
- local(*DIR);
-
- ($cdev, $cino) = stat('.');
- for (;;) {
- my $direntry;
- ($odev, $oino) = ($cdev, $cino);
- chdir('..');
- ($cdev, $cino) = stat('.');
- last if $odev == $cdev && $oino == $cino;
- opendir(DIR, '.');
- for (;;) {
- $direntry = readdir(DIR);
- next if $direntry eq '.';
- next if $direntry eq '..';
-
- last unless defined $direntry;
- ($tdev, $tino) = lstat($direntry);
- last unless $tdev != $odev || $tino != $oino;
- }
- closedir(DIR);
- unshift(@path, $direntry);
- }
- chdir($path = '/' . join('/', @path));
- $path;
-}
-
-
# Keeps track of current working directory in PWD environment var
# Usage:
# use Cwd 'chdir';
my $chdir_init = 0;
sub chdir_init {
- if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'msdos') {
+ if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') {
my($dd,$di) = stat('.');
my($pd,$pi) = stat($ENV{'PWD'});
if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) {
}
}
else {
- $ENV{'PWD'} = cwd();
+ my $wd = cwd();
+ $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32';
+ $ENV{'PWD'} = $wd;
}
# Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar)
- if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|) {
+ if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) {
my($pd,$pi) = stat($2);
my($dd,$di) = stat($1);
if (defined $pd and defined $dd and $di == $pi and $dd == $pd) {
}
sub chdir {
- my $newdir = shift || ''; # allow for no arg (chdir to HOME dir)
- $newdir =~ s|///*|/|g;
+ my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir)
+ $newdir =~ s|///*|/|g unless $^O eq 'MSWin32';
chdir_init() unless $chdir_init;
+ my $newpwd;
+ if ($^O eq 'MSWin32') {
+ # get the full path name *before* the chdir()
+ $newpwd = Win32::GetFullPathName($newdir);
+ }
+
return 0 unless CORE::chdir $newdir;
- if ($^O eq 'VMS') { return $ENV{'PWD'} = $ENV{'DEFAULT'} }
- if ($newdir =~ m#^/#) {
+ if ($^O eq 'VMS') {
+ return $ENV{'PWD'} = $ENV{'DEFAULT'}
+ }
+ elsif ($^O eq 'MacOS') {
+ return $ENV{'PWD'} = cwd();
+ }
+ elsif ($^O eq 'MSWin32') {
+ $ENV{'PWD'} = $newpwd;
+ return 1;
+ }
+
+ if ($newdir =~ m#^/#s) {
$ENV{'PWD'} = $newdir;
} else {
my @curdir = split(m#/#,$ENV{'PWD'});
1;
}
-# Taken from Cwd.pm It is really getcwd with an optional
-# parameter instead of '.'
-#
-
-sub abs_path
-{
- my $start = shift || '.';
- my($dotdots, $cwd, @pst, @cst, $dir, @tst);
-
- unless (@cst = stat( $start ))
- {
- carp "stat($start): $!";
- return '';
- }
- $cwd = '';
- $dotdots = $start;
- do
- {
- $dotdots .= '/..';
- @pst = @cst;
- unless (opendir(PARENT, $dotdots))
- {
- carp "opendir($dotdots): $!";
- return '';
- }
- unless (@cst = stat($dotdots))
- {
- carp "stat($dotdots): $!";
- closedir(PARENT);
- return '';
- }
- if ($pst[0] == $cst[0] && $pst[1] == $cst[1])
- {
- $dir = '';
- }
- else
- {
- do
- {
- unless (defined ($dir = readdir(PARENT)))
- {
- carp "readdir($dotdots): $!";
- closedir(PARENT);
- return '';
- }
- $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir"))
- }
- while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] ||
- $tst[1] != $pst[1]);
- }
- $cwd = "$dir/$cwd";
- closedir(PARENT);
- } while ($dir);
- chop($cwd); # drop the trailing /
- $cwd;
-}
+# added function alias for those of us more
+# used to the libc function. --tchrist 27-Jan-00
+*realpath = \&abs_path;
sub fast_abs_path {
my $cwd = getcwd();
- my $path = shift || '.';
- chdir($path) || croak "Cannot chdir to $path:$!";
+ my $path = @_ ? shift : '.';
+ CORE::chdir($path) || croak "Cannot chdir to $path:$!";
my $realpath = getcwd();
- chdir($cwd) || croak "Cannot chdir back to $cwd:$!";
+ CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!";
$realpath;
}
+# added function alias to follow principle of least surprise
+# based on previous aliasing. --tchrist 27-Jan-00
+*fast_realpath = \&fast_abs_path;
+
# --- PORTING SECTION ---
# VMS: $ENV{'DEFAULT'} points to default directory at all times
-# 06-Mar-1996 Charles Bailey bailey@genetics.upenn.edu
+# 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu
# Note: Use of Cwd::chdir() causes the logical name PWD to be defined
# in the process logical name table as the default device and directory
# seen by Perl. This may not be the same as the default device
}
sub _win32_cwd {
- $ENV{'PWD'} = Win32::GetCurrentDirectory();
+ $ENV{'PWD'} = Win32::GetCwd();
$ENV{'PWD'} =~ s:\\:/:g ;
return $ENV{'PWD'};
}
*_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd &&
- defined &Win32::GetCurrentDirectory);
+ defined &Win32::GetCwd);
*_NT_cwd = \&_os2_cwd unless defined &_NT_cwd;
-sub _msdos_cwd {
- $ENV{'PWD'} = `command /c cd`;
+sub _dos_cwd {
+ if (!defined &Dos::GetCwd) {
+ $ENV{'PWD'} = `command /c cd`;
+ chop $ENV{'PWD'};
+ $ENV{'PWD'} =~ s:\\:/:g ;
+ } else {
+ $ENV{'PWD'} = Dos::GetCwd();
+ }
+ return $ENV{'PWD'};
+}
+
+sub _qnx_cwd {
+ $ENV{'PWD'} = `/usr/bin/fullpath -t`;
chop $ENV{'PWD'};
- $ENV{'PWD'} =~ s:\\:/:g ;
+ return $ENV{'PWD'};
+}
+
+sub _qnx_abs_path {
+ my $path = @_ ? shift : '.';
+ my $realpath=`/usr/bin/fullpath -t $path`;
+ chop $realpath;
+ return $realpath;
+}
+
+sub _epoc_cwd {
+ $ENV{'PWD'} = EPOC::getcwd();
return $ENV{'PWD'};
}
{
- local $^W = 0; # assignments trigger 'subroutine redefined' warning
+ no warnings; # assignments trigger 'subroutine redefined' warning
if ($^O eq 'VMS') {
*cwd = \&_vms_cwd;
*fastcwd = \&cwd;
*abs_path = \&fast_abs_path;
}
- elsif ($^O eq 'msdos') {
- *cwd = \&_msdos_cwd;
- *getcwd = \&_msdos_cwd;
- *fastgetcwd = \&_msdos_cwd;
- *fastcwd = \&_msdos_cwd;
+ elsif ($^O eq 'dos') {
+ *cwd = \&_dos_cwd;
+ *getcwd = \&_dos_cwd;
+ *fastgetcwd = \&_dos_cwd;
+ *fastcwd = \&_dos_cwd;
*abs_path = \&fast_abs_path;
}
+ elsif ($^O eq 'qnx') {
+ *cwd = \&_qnx_cwd;
+ *getcwd = \&_qnx_cwd;
+ *fastgetcwd = \&_qnx_cwd;
+ *fastcwd = \&_qnx_cwd;
+ *abs_path = \&_qnx_abs_path;
+ *fast_abs_path = \&_qnx_abs_path;
+ }
+ elsif ($^O eq 'cygwin') {
+ *getcwd = \&cwd;
+ *fastgetcwd = \&cwd;
+ *fastcwd = \&cwd;
+ *abs_path = \&fast_abs_path;
+ }
+ elsif ($^O eq 'epoc') {
+ *cwd = \&_epoc_cwd;
+ *getcwd = \&_epoc_cwd;
+ *fastgetcwd = \&_epoc_cwd;
+ *fastcwd = \&_epoc_cwd;
+ *abs_path = \&fast_abs_path;
+ }
+ elsif ($^O eq 'MacOS') {
+ *getcwd = \&cwd;
+ *fastgetcwd = \&cwd;
+ *fastcwd = \&cwd;
+ *abs_path = \&fast_abs_path;
+ }
}
# package main; eval join('',<DATA>) || die $@; # quick test