X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCwd.pm;h=d7e60d6dc979572e2176b781797921bd0b11d49e;hb=c7574462553caa93de43b87874d7657569d04353;hp=d86428cdb8ab342524bf6bd17ea7b62c03af8de9;hpb=929327b2dc1cf9eaf4d36b4f965b09fd8c233e8e;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/Cwd.pm b/lib/Cwd.pm index d86428c..d7e60d6 100644 --- a/lib/Cwd.pm +++ b/lib/Cwd.pm @@ -1,96 +1,214 @@ package Cwd; -require 5.000; +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 $ENV{'PWD'}; +This module provides functions for determining the pathname of the +current working directory. It is recommended that getcwd (or another +*cwd() function) be used in I code to ensure portability. - use Cwd 'abs_path'; # aka realpath() - print abs_path($ENV{'PWD'}); +By default, it exports the functions cwd(), getcwd(), fastcwd(), and +fastgetcwd() into the caller's namespace. - use Cwd 'fast_abs_path'; - print fast_abs_path($ENV{'PWD'}); -=head1 DESCRIPTION +=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 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 -The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions -in Perl. - -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). Also callable as -realpath(). - -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 with the message "Unstable directory path, -current directory changed unexpectedly". That should never happen. - -The fast_abs_path() function looks the same as abs_path(), but runs faster. -And like fastcwd() is more dangerous. - -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 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.) Note that it will only be -kept up to date if all packages which use chdir import it from Cwd. +=over 4 + +=item * + +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. + +=item * + +Actually, on Mac OS, the C, C and C +functions are all aliases for the C function, which, on Mac OS, +calls `pwd`. Likewise, the C function is an alias for +C. + +=back + +=head1 SEE ALSO + +L =cut -## use strict; +use strict; use Carp; -$VERSION = '2.03'; - -require Exporter; -@ISA = qw(Exporter); -@EXPORT = qw(cwd getcwd fastcwd fastgetcwd); -@EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); +our $VERSION = '2.06'; + +use base qw/ Exporter /; +our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); +our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); + +# sys_cwd may keep the builtin command + +# All the functionality of this module may provided by builtins, +# there is no sense to process the rest of the file. +# The best choice may be to have this in BEGIN, but how to return from BEGIN? + +if ($^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 $cwd; - chop($cwd = `pwd`); + my $cwd = `$pwd_cmd`; + # `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 # @@ -101,6 +219,7 @@ sub getcwd abs_path('.'); } + # By John Bazik # # Usage: $cwd = &fastcwd; @@ -156,7 +275,7 @@ sub fastcwd { my $chdir_init = 0; sub chdir_init { - if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos') { + if ($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) { @@ -164,10 +283,12 @@ sub chdir_init { } } 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|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { + 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) { @@ -178,11 +299,27 @@ sub chdir_init { } 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'} = $ENV{'DEFAULT'} } + + if ($^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; @@ -201,35 +338,59 @@ sub chdir { } -# By Jeff "japhy" Pinyan (07/23/2000) -# usage: abs_path(PATHNAME) -# see the docs - -sub abs_path { - my $base = @_ ? $_[0] : "."; - my $path = ""; - my $file; - - do { - my @devino = (stat($base))[0,1] or - carp("stat($base): $!"), return; - - $base .= "/.."; +# 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); - opendir PREV, $base or carp("opendir($base): $!"), return; - while (defined($file = readdir PREV)) { - next if $file eq "." or $file eq ".."; - my @entry = (lstat("$base/$file"))[0,1] or - carp("lstat($base/$file): $!"), return; - last if $devino[0] == $entry[0] and $devino[1] == $entry[1]; + unless (@cst = stat( $start )) + { + carp "stat($start): $!"; + return ''; } - closedir PREV; - - $path = (defined $file and $file) . "/$path"; - } while defined $file; - - length($path) > 1 and chop $path; - return $path; + $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; } @@ -239,7 +400,8 @@ sub abs_path { sub fast_abs_path { my $cwd = getcwd(); - my $path = shift || '.'; + 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 $cwd:$!"; @@ -308,12 +470,17 @@ sub _qnx_cwd { } sub _qnx_abs_path { - my $path = shift || '.'; + my $path = @_ ? shift : '.'; my $realpath=`/usr/bin/fullpath -t $path`; chop $realpath; return $realpath; } +sub _epoc_cwd { + $ENV{'PWD'} = EPOC::getcwd(); + return $ENV{'PWD'}; +} + { no warnings; # assignments trigger 'subroutine redefined' warning @@ -332,6 +499,7 @@ sub _qnx_abs_path { *fastcwd = \&_NT_cwd; *fastgetcwd = \&_NT_cwd; *abs_path = \&fast_abs_path; + *realpath = \&fast_abs_path; } elsif ($^O eq 'os2') { # sys_cwd may keep the builtin command @@ -348,7 +516,7 @@ sub _qnx_abs_path { *fastcwd = \&_dos_cwd; *abs_path = \&fast_abs_path; } - elsif ($^O eq 'qnx') { + elsif ($^O =~ m/^(?:qnx|nto)$/ ) { *cwd = \&_qnx_cwd; *getcwd = \&_qnx_cwd; *fastgetcwd = \&_qnx_cwd; @@ -362,15 +530,20 @@ sub _qnx_abs_path { *fastcwd = \&cwd; *abs_path = \&fast_abs_path; } + elsif ($^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('',) || 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";