X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCwd.pm;h=e7d12e3ae79a42c17eabcd0c89ce775e20e4ab87;hb=8e742a20f09cb882e499103f4c5f4964764f2a86;hp=632931b133929e12d7e814a67cb736a018f6888a;hpb=f5f423e4590905c45492eda1312cb2f76a6ef9a7;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/Cwd.pm b/lib/Cwd.pm index 632931b..e7d12e3 100644 --- a/lib/Cwd.pm +++ b/lib/Cwd.pm @@ -1,5 +1,5 @@ package Cwd; -require 5.000; +$VERSION = $VERSION = '2.17_03'; =head1 NAME @@ -8,82 +8,160 @@ 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 = fastcwd; +=head1 DESCRIPTION - use Cwd; - $dir = fastgetcwd; +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 'chdir'; - chdir "/tmp"; - print $ENV{'PWD'}; +By default, it exports the functions cwd(), getcwd(), fastcwd(), and +fastgetcwd() (and, on Win32, getdcwd()) into the caller's namespace. - use Cwd 'abs_path'; # aka realpath() - print abs_path($ENV{'PWD'}); - use Cwd 'fast_abs_path'; - print fast_abs_path($ENV{'PWD'}); +=head2 getcwd and friends -=head1 DESCRIPTION +Each of these functions are called without arguments and return the +absolute path of the current working directory. -This module provides functions for determining the pathname of the -current working directory. By default, it exports the functions -cwd(), getcwd(), fastcwd(), and fastgetcwd() into the caller's -namespace. Each of these functions are called without arguments and -return the absolute path of the current working directory. It is -recommended that cwd (or another *cwd() function) be used in I -code to ensure portability. - -The cwd() is the most natural and safe form for the current -architecture. For most systems it is identical to `pwd` (but without -the trailing line terminator). - -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 with the message "Unstable directory path, -current directory changed unexpectedly". That should never happen. +=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). + +=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(). -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). This function is also -callable as realpath(). +=item getdcwd -The fast_abs_path() function looks the same as abs_path() but runs -faster and, like fastcwd(), is more dangerous. + my $cwd = getdcwd(); + my $cwd = getdcwd('C:'); -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. +The getdcwd() function is also provided on Win32 to get the current working +directory on the specified drive, since Windows maintains a separate current +working directory for each drive. If no drive is specified then the current +drive is assumed. -=cut +This function simply calls the Microsoft C library _getdcwd() function. -use strict; +=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. If no argument is +given they'll use the current working directory. + +=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). -use Carp; +=item realpath -our $VERSION = '2.04'; + my $abs_path = realpath($file); -use base qw/ Exporter /; -our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); -our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); +A synonym for abs_path(). + +=item fast_abs_path + + my $abs_path = fast_abs_path($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 * + +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 AUTHOR + +Originally by the perl5-porters. + +Now maintained by Ken Williams + +=head1 SEE ALSO + +L + +=cut + +use strict; +use Exporter; +use vars qw(@ISA @EXPORT @EXPORT_OK); + +@ISA = qw/ Exporter /; +@EXPORT = qw(cwd getcwd fastcwd fastgetcwd); +push @EXPORT, qw(getdcwd) if $^O eq 'MSWin32'; +@EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); # sys_cwd may keep the builtin command @@ -91,28 +169,133 @@ our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); # there is no sense to process the rest of the file. # The best choice may be to have this in BEGIN, but how to return from BEGIN? -if ($^O eq 'os2' && defined &sys_cwd && defined &sys_abspath) { +if ($^O eq 'os2') { 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; + + *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; + *getcwd = \&cwd; + *fastgetcwd = \&cwd; + *fastcwd = \&cwd; + + *fast_abs_path = \&sys_abspath if defined &sys_abspath; + *abs_path = \&fast_abs_path; + *realpath = \&fast_abs_path; + *fast_realpath = \&fast_abs_path; + return 1; } eval { require XSLoader; + local $^W = 0; XSLoader::load('Cwd'); }; -# The 'natural and safe form' for UNIX (pwd may be setuid root) +# Big nasty table of function aliases +my %METHOD_MAP = + ( + VMS => + { + cwd => '_vms_cwd', + getcwd => '_vms_cwd', + fastcwd => '_vms_cwd', + fastgetcwd => '_vms_cwd', + abs_path => '_vms_abs_path', + fast_abs_path => '_vms_abs_path', + }, + + MSWin32 => + { + # We assume that &_NT_cwd is defined as an XSUB or in the core. + cwd => '_NT_cwd', + getcwd => '_NT_cwd', + fastcwd => '_NT_cwd', + fastgetcwd => '_NT_cwd', + abs_path => 'fast_abs_path', + realpath => 'fast_abs_path', + }, + + dos => + { + cwd => '_dos_cwd', + getcwd => '_dos_cwd', + fastgetcwd => '_dos_cwd', + fastcwd => '_dos_cwd', + abs_path => 'fast_abs_path', + }, + + qnx => + { + cwd => '_qnx_cwd', + getcwd => '_qnx_cwd', + fastgetcwd => '_qnx_cwd', + fastcwd => '_qnx_cwd', + abs_path => '_qnx_abs_path', + fast_abs_path => '_qnx_abs_path', + }, + + cygwin => + { + getcwd => 'cwd', + fastgetcwd => 'cwd', + fastcwd => 'cwd', + abs_path => 'fast_abs_path', + realpath => 'fast_abs_path', + }, + + epoc => + { + cwd => '_epoc_cwd', + getcwd => '_epoc_cwd', + fastgetcwd => '_epoc_cwd', + fastcwd => '_epoc_cwd', + abs_path => 'fast_abs_path', + }, + + MacOS => + { + getcwd => 'cwd', + fastgetcwd => 'cwd', + fastcwd => 'cwd', + abs_path => 'fast_abs_path', + }, + ); + +$METHOD_MAP{NT} = $METHOD_MAP{MSWin32}; +$METHOD_MAP{nto} = $METHOD_MAP{qnx}; + + +# 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 ('/bin/pwd', + '/usr/bin/pwd', + '/QOpenSys/bin/pwd', # OS/400 PASE. + ) { + + if( -x $try ) { + $pwd_cmd = $try; + last; + } +} +unless ($pwd_cmd) { + # Isn't this wrong? _backtick_pwd() will fail if somenone has + # pwd in their path but it is not /bin/pwd or /usr/bin/pwd? + # See [perl #16774]. --jhi + $pwd_cmd = 'pwd'; +} + +# Lazy-load Carp +sub _carp { require Carp; Carp::carp(@_) } +sub _croak { require Carp; Carp::croak(@_) } +# The 'natural and safe form' for UNIX (pwd may be setuid root) sub _backtick_pwd { - my $cwd = `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; $cwd; @@ -121,9 +304,12 @@ sub _backtick_pwd { # Since some ports may predefine cwd internally (e.g., NT) # we take care not to override an existing definition for cwd(). -unless(defined &cwd) { +unless ($METHOD_MAP{$^O}{cwd} or defined &cwd) { # The pwd command is not available in some chroot(2)'ed environments - if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) { + my $sep = $Config::Config{path_sep} || ':'; + if( $^O eq 'MacOS' || (defined $ENV{PATH} && + grep { -x "$_/pwd" } split($sep, $ENV{PATH})) ) + { *cwd = \&_backtick_pwd; } else { @@ -144,6 +330,54 @@ 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. + # 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; + $path; +} + + # Keeps track of current working directory in PWD environment var # Usage: # use Cwd 'chdir'; @@ -214,16 +448,131 @@ sub chdir { 1; } + +# In case the XS version doesn't load. +*abs_path = \&_perl_abs_path unless defined &abs_path; +sub _perl_abs_path(;$) +{ + my $start = @_ ? shift : '.'; + my($dotdots, $cwd, @pst, @cst, $dir, @tst); + + unless (@cst = stat( $start )) + { + _carp("stat($start): $!"); + return ''; + } + + unless (-d _) { + # Make sure we can be invoked on plain files, not just directories. + # NOTE that this routine assumes that '/' is the only directory separator. + + my ($dir, $file) = $start =~ m{^(.*)/(.+)$} + or return cwd() . '/' . $start; + + if (-l _) { + my $link_target = readlink($start); + die "Can't resolve link $start: $!" unless defined $link_target; + + require File::Spec; + $link_target = $dir . '/' . $link_target + unless File::Spec->file_name_is_absolute($link_target); + + return abs_path($link_target); + } + + return abs_path($dir) . '/' . $file; + } + + $cwd = ''; + $dotdots = $start; + do + { + $dotdots .= '/..'; + @pst = @cst; + local *PARENT; + 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 $Curdir; sub fast_abs_path { my $cwd = getcwd(); - my $path = @_ ? shift : '.'; - CORE::chdir($path) || croak "Cannot chdir to $path:$!"; + require File::Spec; + my $path = @_ ? shift : ($Curdir ||= File::Spec->curdir); + + # Detaint else we'll explode in taint mode. This is safe because + # we're not doing anything dangerous with it. + ($path) = $path =~ /(.*)/; + ($cwd) = $cwd =~ /(.*)/; + + unless (-e $path) { + _croak("$path: No such file or directory"); + } + + unless (-d _) { + # Make sure we can be invoked on plain files, not just directories. + + my ($vol, $dir, $file) = File::Spec->splitpath($path); + return File::Spec->catfile($cwd, $path) unless length $dir; + + if (-l $path) { + my $link_target = readlink($path); + die "Can't resolve link $path: $!" unless defined $link_target; + + $link_target = File::Spec->catpath($vol, $dir, $link_target) + unless File::Spec->file_name_is_absolute($link_target); + + return fast_abs_path($link_target); + } + + return fast_abs_path(File::Spec->catpath($vol, $dir, '')) . '/' . $file; + } + + if (!CORE::chdir($path)) { + _croak("Cannot chdir to $path: $!"); + } my $realpath = getcwd(); - CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; + if (! ((-d $cwd) && (CORE::chdir($cwd)))) { + _croak("Cannot chdir back to $cwd: $!"); + } $realpath; } @@ -249,13 +598,16 @@ sub _vms_cwd { sub _vms_abs_path { return $ENV{'DEFAULT'} unless @_; my $path = VMS::Filespec::pathify($_[0]); - croak("Invalid path name $_[0]") unless defined $path; + if (! defined $path) + { + _croak("Invalid path name $_[0]") + } return VMS::Filespec::rmsexpand($path); } sub _os2_cwd { $ENV{'PWD'} = `cmd /c cd`; - chop $ENV{'PWD'}; + chomp $ENV{'PWD'}; $ENV{'PWD'} =~ s:\\:/:g ; return $ENV{'PWD'}; } @@ -274,7 +626,7 @@ sub _win32_cwd { sub _dos_cwd { if (!defined &Dos::GetCwd) { $ENV{'PWD'} = `command /c cd`; - chop $ENV{'PWD'}; + chomp $ENV{'PWD'}; $ENV{'PWD'} =~ s:\\:/:g ; } else { $ENV{'PWD'} = Dos::GetCwd(); @@ -283,15 +635,26 @@ sub _dos_cwd { } sub _qnx_cwd { + local $ENV{PATH} = ''; + local $ENV{CDPATH} = ''; + local $ENV{ENV} = ''; $ENV{'PWD'} = `/usr/bin/fullpath -t`; - chop $ENV{'PWD'}; + chomp $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; + local *REALPATH; + + open(REALPATH, '-|', '/usr/bin/fullpath', '-t', $path) or + die "Can't open /usr/bin/fullpath: $!"; + my $realpath = ; + close REALPATH; + chomp $realpath; return $realpath; } @@ -300,76 +663,18 @@ sub _epoc_cwd { return $ENV{'PWD'}; } -{ - no warnings; # assignments trigger 'subroutine redefined' warning - if ($^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 ($^O eq 'dos') { - *cwd = \&_dos_cwd; - *getcwd = \&_dos_cwd; - *fastgetcwd = \&_dos_cwd; - *fastcwd = \&_dos_cwd; - *abs_path = \&fast_abs_path; - } - elsif ($^O eq 'qnx') { - *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; - } +# Now that all the base-level functions are set up, alias the +# user-level functions to the right places + +if (exists $METHOD_MAP{$^O}) { + my $map = $METHOD_MAP{$^O}; + foreach my $name (keys %$map) { + no warnings; # assignments trigger 'subroutine redefined' warning + no strict 'refs'; + *{$name} = \&{$map->{$name}}; + } } -# 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";