X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCwd.pm;h=5b5f21672bd66d12e5a64726724d829876857aa3;hb=0bd43963443f227c8bd1734af34fc6e6a7d2d54e;hp=79725d1f21d79ce33c9b6bafb7e2012b06781e16;hpb=a60299adcfec24c254392ea74d545f131d3e4209;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/Cwd.pm b/lib/Cwd.pm
index 79725d1..5b5f216 100644
--- a/lib/Cwd.pm
+++ b/lib/Cwd.pm
@@ -1,5 +1,5 @@
 package Cwd;
-require 5.6.0;
+use 5.006;
 
 =head1 NAME
 
@@ -95,7 +95,7 @@ A synonym for abs_path().
 
 =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.
 
@@ -168,6 +168,7 @@ if ($^O eq 'os2' && defined &sys_cwd && defined &sys_abspath) {
 
 eval {
     require XSLoader;
+    undef *Cwd::fastcwd; # avoid redefinition warning
     XSLoader::load('Cwd');
 };
 
@@ -187,6 +188,8 @@ $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;
@@ -197,7 +200,9 @@ sub _backtick_pwd {
 
 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 {
@@ -218,6 +223,54 @@ sub getcwd
     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.
+    # 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;
+}
+
+
 # Keeps track of current working directory in PWD environment var
 # Usage:
 #	use Cwd 'chdir';
@@ -288,6 +341,63 @@ sub 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;
@@ -358,12 +468,18 @@ sub _dos_cwd {
 }
 
 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 $realpath;
@@ -393,6 +509,7 @@ sub _epoc_cwd {
         *fastcwd	= \&_NT_cwd;
         *fastgetcwd	= \&_NT_cwd;
         *abs_path	= \&fast_abs_path;
+        *realpath   = \&fast_abs_path;
     }
     elsif ($^O eq 'os2') {
         # sys_cwd may keep the builtin command
@@ -438,13 +555,5 @@ sub _epoc_cwd {
     }
 }
 
-# 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";