package Cwd;
-require 5.000;
-require Exporter;
+use 5.006;
=head1 NAME
-getcwd - get pathname of current working directory
+Cwd - get pathname of current working directory
=head1 SYNOPSIS
use Cwd;
- $dir = cwd;
+ my $dir = getcwd;
- use Cwd;
- $dir = getcwd;
+ use Cwd 'abs_path';
+ my $abs_path = abs_path($file);
- use Cwd;
- $dir = fastgetcwd;
+=head1 DESCRIPTION
- use Cwd 'chdir';
- chdir "/tmp";
- print $ENV{'PWD'};
+This module provides functions for determining the pathname of the
+current working directory. It is recommended that getcwd (or another
+*cwd() function) be used in I<all> code to ensure portability.
-=head1 DESCRIPTION
+By default, it exports the functions cwd(), getcwd(), fastcwd(), and
+fastgetcwd() into the caller's namespace.
+
+
+=head2 getcwd and friends
+
+Each of these functions are called without arguments and return the
+absolute path of the current working directory.
+
+=over 4
+
+=item getcwd
+
+ my $cwd = getcwd();
+
+Returns the current working directory.
+
+Re-implements the getcwd(3) (or getwd(3)) functions in Perl.
+
+=item cwd
+
+ my $cwd = cwd();
+
+The cwd() is the most natural form for the current architecture. For
+most systems it is identical to `pwd` (but without the trailing line
+terminator).
+
+Unfortunately, cwd() tends to break if called under taint mode.
+
+=item fastcwd
+
+ my $cwd = fastcwd();
+
+A more dangerous version of getcwd(), but potentially faster.
+
+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.
+
+=item fastgetcwd
+
+ my $cwd = fastgetcwd();
+
+The fastgetcwd() function is provided as a synonym for cwd().
+
+=back
+
+
+=head2 abs_path and friends
+
+These functions are exported only on request. They each take a single
+argument and return the absolute pathname for it.
+
+=over 4
+
+=item abs_path
+
+ my $abs_path = abs_path($file);
+
+Uses the same algorithm as getcwd(). Symbolic links and relative-path
+components ("." and "..") are resolved to return the canonical
+pathname, just like realpath(3).
+
+=item realpath
+
+ my $abs_path = realpath($file);
+
+A synonym for abs_path().
+
+=item fast_abs_path
+
+ my $abs_path = abs_path($file);
+
+A more dangerous, but potentially faster version of abs_path.
+
+=back
+
+=head2 $ENV{PWD}
+
+If you ask to override your chdir() built-in function,
+
+ use Cwd qw(chdir);
+
+then your PWD environment variable will be kept up to date. Note that
+it will only be kept up to date if all packages which use chdir import
+it from Cwd.
+
+
+=head1 NOTES
+
+=over 4
+
+=item *
-The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions
-in Perl.
+Since the path seperators are different on some operating systems ('/'
+on Unix, ':' on MacPerl, etc...) we recommend you use the File::Spec
+modules wherever portability is a concern.
-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.
+=item *
-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.
+Actually, on Mac OS, the C<getcwd()>, C<fastgetcwd()> and C<fastcwd()>
+functions are all aliases for the C<cwd()> function, which, on Mac OS,
+calls `pwd`. Likewise, the C<abs_path()> function is an alias for
+C<fast_abs_path()>.
-If you ask to override your chdir() built-in function, then your PWD
-environment variable will be kept up to date. (See
-L<perlsub/Overriding Builtin Functions>.) Note that it will only be
-kept up to date if all packages which use chdir import it from Cwd.
+=back
+
+=head1 SEE ALSO
+
+L<File::chdir>
=cut
-@ISA = qw(Exporter);
-@EXPORT = qw(cwd getcwd fastcwd fastgetcwd);
-@EXPORT_OK = qw(chdir);
+use strict;
+
+use Carp;
+
+our $VERSION = '2.06';
+
+use base qw/ Exporter /;
+our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd);
+our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath);
+
+# sys_cwd may keep the builtin command
-# use strict;
+# All the functionality of this module may provided by builtins,
+# there is no sense to process the rest of the file.
+# The best choice may be to have this in BEGIN, but how to return from BEGIN?
-sub _backtick_pwd { # The 'natural and safe form' for UNIX (pwd may be setuid root)
- my $cwd;
- chop($cwd = `pwd`);
+if ($^O eq 'os2' && defined &sys_cwd && defined &sys_abspath) {
+ local $^W = 0;
+ *cwd = \&sys_cwd;
+ *getcwd = \&cwd;
+ *fastgetcwd = \&cwd;
+ *fastcwd = \&cwd;
+ *abs_path = \&sys_abspath;
+ *fast_abs_path = \&abs_path;
+ *realpath = \&abs_path;
+ *fast_realpath = \&abs_path;
+ return 1;
+}
+
+eval {
+ require XSLoader;
+ undef *Cwd::fastcwd; # avoid redefinition warning
+ XSLoader::load('Cwd');
+};
+
+
+# Find the pwd command in the expected locations. We assume these
+# are safe. This prevents _backtick_pwd() consulting $ENV{PATH}
+# so everything works under taint mode.
+my $pwd_cmd;
+foreach my $try (qw(/bin/pwd /usr/bin/pwd)) {
+ if( -x $try ) {
+ $pwd_cmd = $try;
+ last;
+ }
+}
+$pwd_cmd ||= 'pwd';
+
+# The 'natural and safe form' for UNIX (pwd may be setuid root)
+sub _backtick_pwd {
+ my $cwd = `$pwd_cmd`;
+ # Belt-and-suspenders in case someone said "undef $/".
+ local $/ = "\n";
+ # `pwd` may fail e.g. if the disk is full
+ chomp($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, $cino) = stat('.');
+ my($orig_cdev, $orig_cino) = stat('.');
+ ($cdev, $cino) = ($orig_cdev, $orig_cino);
for (;;) {
my $direntry;
($odev, $oino) = ($cdev, $cino);
- chdir('..');
+ CORE::chdir('..') || return undef;
($cdev, $cino) = stat('.');
last if $odev == $cdev && $oino == $cino;
- opendir(DIR, '.');
+ opendir(DIR, '.') || return undef;
for (;;) {
$direntry = readdir(DIR);
+ last unless defined $direntry;
next if $direntry eq '.';
next if $direntry eq '..';
- last unless defined $direntry;
($tdev, $tino) = lstat($direntry);
last unless $tdev != $odev || $tino != $oino;
}
closedir(DIR);
+ return undef unless defined $direntry; # should never happen
unshift(@path, $direntry);
}
- chdir($path = '/' . join('/', @path));
+ $path = '/' . join('/', @path);
+ if ($^O eq 'apollo') { $path = "/".$path; }
+ # At this point $path may be tainted (if tainting) and chdir would fail.
+ # To be more useful we untaint it then check that we landed where we started.
+ $path = $1 if $path =~ /^(.*)\z/s; # untaint
+ CORE::chdir($path) || return undef;
+ ($cdev, $cino) = stat('.');
+ die "Unstable directory path, current directory changed unexpectedly"
+ if $cdev != $orig_cdev || $cino != $orig_cino;
$path;
}
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'});
}
+# In case the XS version doesn't load.
+*abs_path = \&_perl_abs_path unless defined &abs_path;
+sub _perl_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])
+ {
+ $dir = undef;
+ }
+ else
+ {
+ do
+ {
+ unless (defined ($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 = (defined $dir ? "$dir" : "" ) . "/$cwd" ;
+ closedir(PARENT);
+ } while (defined $dir);
+ chop($cwd) unless $cwd eq '/'; # 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();
+ require File::Spec;
+ my $path = @_ ? shift : File::Spec->curdir;
+ CORE::chdir($path) || croak "Cannot chdir to $path:$!";
+ my $realpath = getcwd();
+ CORE::chdir($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
+# 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
# and directory seen by DCL after Perl exits, since the effects
# the CRTL chdir() function persist only until Perl exits.
sub _vms_cwd {
- return $ENV{'DEFAULT'}
+ return $ENV{'DEFAULT'};
}
+
+sub _vms_abs_path {
+ return $ENV{'DEFAULT'} unless @_;
+ my $path = VMS::Filespec::pathify($_[0]);
+ croak("Invalid path name $_[0]") unless defined $path;
+ return VMS::Filespec::rmsexpand($path);
+}
+
sub _os2_cwd {
$ENV{'PWD'} = `cmd /c cd`;
chop $ENV{'PWD'};
return $ENV{'PWD'};
}
-sub _msdos_cwd {
- $ENV{'PWD'} = `command /c cd`;
- chop $ENV{'PWD'};
+sub _win32_cwd {
+ $ENV{'PWD'} = Win32::GetCwd();
$ENV{'PWD'} =~ s:\\:/:g ;
return $ENV{'PWD'};
}
+*_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd &&
+ defined &Win32::GetCwd);
+
+*_NT_cwd = \&_os2_cwd unless defined &_NT_cwd;
+
+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'};
+ 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;
- *getcwd = \&_vms_cwd;
- *fastcwd = \&_vms_cwd;
- *fastgetcwd = \&_vms_cwd;
+ *cwd = \&_vms_cwd;
+ *getcwd = \&_vms_cwd;
+ *fastcwd = \&_vms_cwd;
+ *fastgetcwd = \&_vms_cwd;
+ *abs_path = \&_vms_abs_path;
+ *fast_abs_path = \&_vms_abs_path;
}
elsif ($^O eq 'NT' or $^O eq 'MSWin32') {
# We assume that &_NT_cwd is defined as an XSUB or in the core.
- *getcwd = \&_NT_cwd;
- *fastcwd = \&_NT_cwd;
- *fastgetcwd = \&_NT_cwd;
+ *cwd = \&_NT_cwd;
+ *getcwd = \&_NT_cwd;
+ *fastcwd = \&_NT_cwd;
+ *fastgetcwd = \&_NT_cwd;
+ *abs_path = \&fast_abs_path;
+ *realpath = \&fast_abs_path;
}
elsif ($^O eq 'os2') {
# sys_cwd may keep the builtin command
- *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd;
- *getcwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd;
- *fastgetcwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd;
- *fastcwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd;
+ *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd;
+ *getcwd = \&cwd;
+ *fastgetcwd = \&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 ($^O =~ m/^(?:qnx|nto)$/ ) {
+ *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 $@; # quick test
1;
-
-__END__
-BEGIN { import Cwd qw(:DEFAULT chdir); }
-print join("\n", cwd, getcwd, fastcwd, "");
-chdir('..');
-print join("\n", cwd, getcwd, fastcwd, "");
-print "$ENV{PWD}\n";