package Cwd;
require 5.000;
-require Exporter;
+=head1 NAME
+
+getcwd - get pathname of current working directory
+
+=head1 SYNOPSIS
+
+ use Cwd;
+ $dir = cwd;
+
+ use Cwd;
+ $dir = getcwd;
+
+ use Cwd;
+ $dir = fastgetcwd;
+
+ use Cwd 'chdir';
+ chdir "/tmp";
+ print $ENV{'PWD'};
+
+=head1 DESCRIPTION
+
+The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions
+in Perl.
+
+The fastcwd() function looks the same as getcwd(), but runs faster.
+It's also more dangerous because it might conceivably chdir() you out
+of a directory that it can't chdir() you back into. If fastcwd
+encounters a problem it will return undef but will probably leave you
+in a different directory. For a measure of extra security, if
+everything appears to have worked, the fastcwd() function will check
+that it leaves you in the same directory that it started in. If it has
+changed it will C<die> with the message "Unstable directory path,
+current directory changed unexpectedly". That should never happen.
+
+The cwd() function looks the same as getcwd and fastgetcwd but is
+implemented using the most natural and safe form for the current
+architecture. For most systems it is identical to `pwd` (but without
+the trailing line terminator).
+
+It is recommended that cwd (or another *cwd() function) is used in
+I<all> code to ensure portability.
+
+If you ask to override your chdir() built-in function, then your PWD
+environment variable will be kept up to date. (See
+L<perlsub/Overriding Builtin Functions>.) Note that it will only be
+kept up to date if all packages which use chdir import it from Cwd.
+
+=cut
+
+## use strict;
+
+use Carp;
+
+$VERSION = '2.00';
+
+require Exporter;
@ISA = qw(Exporter);
-@EXPORT = qw(getcwd fastcwd);
-@EXPORT_OK = qw(chdir);
+@EXPORT = qw(cwd getcwd fastcwd fastgetcwd);
+@EXPORT_OK = qw(chdir abs_path fast_abs_path);
+
+
+# The 'natural and safe form' for UNIX (pwd may be setuid root)
+
+sub _backtick_pwd {
+ my $cwd;
+ chop($cwd = `pwd`);
+ $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;
# By Brandon S. Allbery
return '';
}
$cwd = '';
+ $dotdots = '';
do
{
$dotdots .= '/' if $dotdots;
}
if ($pst[0] == $cst[0] && $pst[1] == $cst[1])
{
- $dir = '';
+ $dir = undef;
}
else
{
do
{
- unless ($dir = readdir(PARENT))
- {
+ unless (defined ($dir = readdir(PARENT)))
+ {
warn "readdir($dotdots): $!";
closedir(PARENT);
return '';
}
unless (@tst = lstat("$dotdots/$dir"))
{
- warn "lstat($dotdots/$dir): $!";
- closedir(PARENT);
- return '';
+ # warn "lstat($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";
+ $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ;
closedir(PARENT);
- } while ($dir);
- chop($cwd);
+ } while (defined $dir);
+ chop($cwd) unless $cwd eq '/'; # drop the trailing /
$cwd;
}
#
# 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.
+
+# List of metachars taken from do_exec() in doio.c
+my $quoted_shell_meta = quotemeta('$&*(){}[]";\\|?<>~`'."'\n");
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, $cino);
- chdir('..');
+ chdir('..') || return undef;
($cdev, $cino) = stat('.');
last if $odev == $cdev && $oino == $cino;
- opendir(DIR, '.');
+ opendir(DIR, '.') || return undef;
for (;;) {
- $_ = readdir(DIR);
- next if $_ eq '.';
- next if $_ eq '..';
+ $direntry = readdir(DIR);
+ last unless defined $direntry;
+ next if $direntry eq '.';
+ next if $direntry eq '..';
- last unless $_;
- ($tdev, $tino) = lstat($_);
+ ($tdev, $tino) = lstat($direntry);
last unless $tdev != $odev || $tino != $oino;
}
closedir(DIR);
- unshift(@path, $_);
+ return undef unless defined $direntry; # should never happen
+ unshift(@path, $direntry);
}
- chdir($path = '/' . join('/', @path));
+ $path = '/' . join('/', @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 $path =~ /^(.*)$/; # untaint
+ chdir($path) || return undef;
+ ($cdev, $cino) = stat('.');
+ die "Unstable directory path, current directory changed unexpectedly"
+ if $cdev != $orig_cdev || $cino != $orig_cino;
$path;
}
-# keeps track of current working directory in PWD environment var
-#
-# $RCSfile: pwd.pl,v $$Revision: 4.1 $$Date: 92/08/07 18:24:11 $
-#
-# $Log: pwd.pl,v $
-#
+# Keeps track of current working directory in PWD environment var
# Usage:
# use Cwd 'chdir';
# chdir $newdir;
-$chdir_init = 0;
+my $chdir_init = 0;
-sub chdir_init{
- if ($ENV{'PWD'}) {
+sub chdir_init {
+ if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'msdos') {
my($dd,$di) = stat('.');
my($pd,$pi) = stat($ENV{'PWD'});
if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) {
- chop($ENV{'PWD'} = `pwd`);
+ $ENV{'PWD'} = cwd();
}
}
else {
- chop($ENV{'PWD'} = `pwd`);
+ $ENV{'PWD'} = cwd();
}
+ # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar)
if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|) {
my($pd,$pi) = stat($2);
my($dd,$di) = stat($1);
}
sub chdir {
- my($newdir) = shift;
+ my $newdir = shift || ''; # allow for no arg (chdir to HOME dir)
+ $newdir =~ s|///*|/|g;
chdir_init() unless $chdir_init;
- return 0 unless (CORE::chdir $newdir);
+ return 0 unless CORE::chdir $newdir;
+ if ($^O eq 'VMS') { return $ENV{'PWD'} = $ENV{'DEFAULT'} }
+
if ($newdir =~ m#^/#) {
$ENV{'PWD'} = $newdir;
- }else{
- my(@curdir) = split(m#/#,$ENV{'PWD'});
- @curdir = '' unless @curdir;
+ } else {
+ my @curdir = split(m#/#,$ENV{'PWD'});
+ @curdir = ('') unless @curdir;
+ my $component;
foreach $component (split(m#/#, $newdir)) {
next if $component eq '.';
pop(@curdir),next if $component eq '..';
}
$ENV{'PWD'} = join('/',@curdir) || '/';
}
+ 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;
+}
+
+sub fast_abs_path {
+ my $cwd = getcwd();
+ my $path = shift || '.';
+ chdir($path) || croak "Cannot chdir to $path:$!";
+ my $realpath = getcwd();
+ chdir($cwd) || croak "Cannot chdir back to $cwd:$!";
+ $realpath;
+}
+
+
+# --- PORTING SECTION ---
+
+# VMS: $ENV{'DEFAULT'} points to default directory at all times
+# 06-Mar-1996 Charles Bailey bailey@genetics.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
+# 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'};
+}
+
+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'};
+ $ENV{'PWD'} =~ s:\\:/:g ;
+ return $ENV{'PWD'};
+}
+
+sub _win32_cwd {
+ $ENV{'PWD'} = Win32::GetCurrentDirectory();
+ $ENV{'PWD'} =~ s:\\:/:g ;
+ return $ENV{'PWD'};
+}
+
+*_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd &&
+ defined &Win32::GetCurrentDirectory);
+
+*_NT_cwd = \&_os2_cwd unless defined &_NT_cwd;
+
+sub _msdos_cwd {
+ $ENV{'PWD'} = `command /c cd`;
+ chop $ENV{'PWD'};
+ $ENV{'PWD'} =~ s:\\:/:g ;
+ return $ENV{'PWD'};
+}
+
+{
+ local $^W = 0; # assignments trigger 'subroutine redefined' warning
+
+ if ($^O eq 'VMS') {
+ *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 $^O eq 'MSWin32') {
+ # We assume that &_NT_cwd is defined as an XSUB or in the core.
+ *cwd = \&_NT_cwd;
+ *getcwd = \&_NT_cwd;
+ *fastcwd = \&_NT_cwd;
+ *fastgetcwd = \&_NT_cwd;
+ *abs_path = \&fast_abs_path;
+ }
+ elsif ($^O eq 'os2') {
+ # sys_cwd may keep the builtin command
+ *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;
+ *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";
projects / p5sagit/p5-mst-13.2.git / blobdiff