package Cwd;
-require 5.6.0;
+use 5.006;
=head1 NAME
Re-implements the getcwd(3) (or getwd(3)) functions in Perl.
+Taint-safe.
+
=item cwd
my $cwd = cwd();
most systems it is identical to `pwd` (but without the trailing line
terminator).
-Unfortunately, cwd() tends to break if called under taint mode.
+Taint-safe.
=item fastcwd
components ("." and "..") are resolved to return the canonical
pathname, just like realpath(3).
+Taint-safe.
+
=item realpath
my $abs_path = realpath($file);
A synonym for abs_path().
+Taint-safe.
+
=item fast_abs_path
- my $abs_path = abs_path($file);
+ my $abs_path = fast_abs_path($file);
A more dangerous, but potentially faster version of abs_path.
+This function is B<Not> taint-safe : you can't use it in programs
+that work under taint mode.
+
=back
=head2 $ENV{PWD}
eval {
require XSLoader;
+ undef *Cwd::fastcwd; # avoid redefinition warning
XSLoader::load('Cwd');
};
# The 'natural and safe form' for UNIX (pwd may be setuid root)
sub _backtick_pwd {
+ local @ENV{qw(PATH IFS CDPATH ENV BASH_ENV)};
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;
$cwd;
unless(defined &cwd) {
# The pwd command is not available in some chroot(2)'ed environments
- if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) {
+ if( $^O eq 'MacOS' || (defined $ENV{PATH} &&
+ grep { -x "$_/pwd" } split(':', $ENV{PATH})) )
+ {
*cwd = \&_backtick_pwd;
}
else {
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, $path);
+ local(*DIR);
+
+ my($orig_cdev, $orig_cino) = stat('.');
+ ($cdev, $cino) = ($orig_cdev, $orig_cino);
+ for (;;) {
+ my $direntry;
+ ($odev, $oino) = ($cdev, $cino);
+ CORE::chdir('..') || return undef;
+ ($cdev, $cino) = stat('.');
+ last if $odev == $cdev && $oino == $cino;
+ opendir(DIR, '.') || return undef;
+ for (;;) {
+ $direntry = readdir(DIR);
+ last unless defined $direntry;
+ next if $direntry eq '.';
+ next if $direntry eq '..';
+
+ ($tdev, $tino) = lstat($direntry);
+ last unless $tdev != $odev || $tino != $oino;
+ }
+ closedir(DIR);
+ return undef unless defined $direntry; # should never happen
+ unshift(@path, $direntry);
+ }
+ $path = '/' . join('/', @path);
+ if ($^O eq 'apollo') { $path = "/".$path; }
+ # At this point $path may be tainted (if tainting) and chdir would fail.
+ # Untaint it then check that we landed where we started.
+ $path =~ /^(.*)\z/s # untaint
+ && CORE::chdir($1) or return undef;
+ ($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
# Usage:
# use Cwd 'chdir';
1;
}
+
+# 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;
my $cwd = getcwd();
require File::Spec;
my $path = @_ ? shift : File::Spec->curdir;
- CORE::chdir($path) || croak "Cannot chdir to $path:$!";
+ CORE::chdir($path) || croak "Cannot chdir to $path: $!";
my $realpath = getcwd();
- CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!";
+ -d $cwd && CORE::chdir($cwd) ||
+ croak "Cannot chdir back to $cwd: $!";
$realpath;
}
}
sub _qnx_cwd {
+ local $ENV{PATH} = '';
+ local $ENV{CDPATH} = '';
+ local $ENV{ENV} = '';
$ENV{'PWD'} = `/usr/bin/fullpath -t`;
chop $ENV{'PWD'};
return $ENV{'PWD'};
}
sub _qnx_abs_path {
+ local $ENV{PATH} = '';
+ local $ENV{CDPATH} = '';
+ local $ENV{ENV} = '';
my $path = @_ ? shift : '.';
my $realpath=`/usr/bin/fullpath -t $path`;
chop $realpath;
*fastcwd = \&_NT_cwd;
*fastgetcwd = \&_NT_cwd;
*abs_path = \&fast_abs_path;
+ *realpath = \&fast_abs_path;
}
elsif ($^O eq 'os2') {
# sys_cwd may keep the builtin command
}
}
-# 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