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Diffstat (limited to 'cpan/Cwd/Cwd.pm')
| -rw-r--r-- | cpan/Cwd/Cwd.pm | 824 |
1 files changed, 824 insertions, 0 deletions
diff --git a/cpan/Cwd/Cwd.pm b/cpan/Cwd/Cwd.pm new file mode 100644 index 0000000000..3a0fda3406 --- /dev/null +++ b/cpan/Cwd/Cwd.pm @@ -0,0 +1,824 @@ +package Cwd; + +=head1 NAME + +Cwd - get pathname of current working directory + +=head1 SYNOPSIS + + use Cwd; + my $dir = getcwd; + + use Cwd 'abs_path'; + my $abs_path = abs_path($file); + +=head1 DESCRIPTION + +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<all> code to ensure portability. + +By default, it exports the functions cwd(), getcwd(), fastcwd(), and +fastgetcwd() (and, on Win32, getdcwd()) into the caller's namespace. + + +=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. + +Exposes the POSIX function getcwd(3) or re-implements it if it's not +available. + +=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<die> 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(). + +=item getdcwd + + my $cwd = getdcwd(); + my $cwd = getdcwd('C:'); + +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. + +This function simply calls the Microsoft C library _getdcwd() function. + +=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). + +=item realpath + + my $abs_path = realpath($file); + +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<getcwd()>, C<fastgetcwd()> and C<fastcwd()> +functions are all aliases for the C<cwd()> function, which, on Mac OS, +calls `pwd`. Likewise, the C<abs_path()> function is an alias for +C<fast_abs_path()>. + +=back + +=head1 AUTHOR + +Originally by the perl5-porters. + +Maintained by Ken Williams <KWILLIAMS@cpan.org> + +=head1 COPYRIGHT + +Copyright (c) 2004 by the Perl 5 Porters. All rights reserved. + +This program is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + +Portions of the C code in this library are copyright (c) 1994 by the +Regents of the University of California. All rights reserved. The +license on this code is compatible with the licensing of the rest of +the distribution - please see the source code in F<Cwd.xs> for the +details. + +=head1 SEE ALSO + +L<File::chdir> + +=cut + +use strict; +use Exporter; +use vars qw(@ISA @EXPORT @EXPORT_OK $VERSION); + +$VERSION = '3.3001'; +my $xs_version = $VERSION; +$VERSION = eval $VERSION; + +@ISA = qw/ Exporter /; +@EXPORT = qw(cwd getcwd fastcwd fastgetcwd); +push @EXPORT, qw(getdcwd) if $^O eq 'MSWin32'; +@EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); + +# sys_cwd may keep the builtin command + +# All the functionality of this module may provided by builtins, +# there is no sense to process the rest of the file. +# The best choice may be to have this in BEGIN, but how to return from BEGIN? + +if ($^O eq 'os2') { + local $^W = 0; + + *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; +} + +# Need to look up the feature settings on VMS. The preferred way is to use the +# VMS::Feature module, but that may not be available to dual life modules. + +my $use_vms_feature; +BEGIN { + if ($^O eq 'VMS') { + if (eval { local $SIG{__DIE__}; require VMS::Feature; }) { + $use_vms_feature = 1; + } + } +} + +# Need to look up the UNIX report mode. This may become a dynamic mode +# in the future. +sub _vms_unix_rpt { + my $unix_rpt; + if ($use_vms_feature) { + $unix_rpt = VMS::Feature::current("filename_unix_report"); + } else { + my $env_unix_rpt = $ENV{'DECC$FILENAME_UNIX_REPORT'} || ''; + $unix_rpt = $env_unix_rpt =~ /^[ET1]/i; + } + return $unix_rpt; +} + +# Need to look up the EFS character set mode. This may become a dynamic +# mode in the future. +sub _vms_efs { + my $efs; + if ($use_vms_feature) { + $efs = VMS::Feature::current("efs_charset"); + } else { + my $env_efs = $ENV{'DECC$EFS_CHARSET'} || ''; + $efs = $env_efs =~ /^[ET1]/i; + } + return $efs; +} + + +# If loading the XS stuff doesn't work, we can fall back to pure perl +eval { + if ( $] >= 5.006 ) { + require XSLoader; + XSLoader::load( __PACKAGE__, $xs_version); + } else { + require DynaLoader; + push @ISA, 'DynaLoader'; + __PACKAGE__->bootstrap( $xs_version ); + } +}; + +# Must be after the DynaLoader stuff: +$VERSION = eval $VERSION; + +# 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', + }, + + # QNX4. QNX6 has a $os of 'nto'. + qnx => + { + cwd => '_qnx_cwd', + getcwd => '_qnx_cwd', + fastgetcwd => '_qnx_cwd', + fastcwd => '_qnx_cwd', + abs_path => '_qnx_abs_path', + fast_abs_path => '_qnx_abs_path', + }, + + cygwin => + { + getcwd => 'cwd', + fastgetcwd => 'cwd', + fastcwd => 'cwd', + abs_path => 'fast_abs_path', + realpath => 'fast_abs_path', + }, + + epoc => + { + cwd => '_epoc_cwd', + getcwd => '_epoc_cwd', + fastgetcwd => '_epoc_cwd', + fastcwd => '_epoc_cwd', + abs_path => 'fast_abs_path', + }, + + MacOS => + { + getcwd => 'cwd', + fastgetcwd => 'cwd', + fastcwd => 'cwd', + abs_path => 'fast_abs_path', + }, + ); + +$METHOD_MAP{NT} = $METHOD_MAP{MSWin32}; + + +# 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; + } +} +my $found_pwd_cmd = defined($pwd_cmd); +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 { + # Localize %ENV entries in a way that won't create new hash keys + my @localize = grep exists $ENV{$_}, qw(PATH IFS CDPATH ENV BASH_ENV); + local @ENV{@localize}; + + 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; + $cwd; +} + +# Since some ports may predefine cwd internally (e.g., NT) +# we take care not to override an existing definition for cwd(). + +unless ($METHOD_MAP{$^O}{cwd} or defined &cwd) { + # The pwd command is not available in some chroot(2)'ed environments + my $sep = $Config::Config{path_sep} || ':'; + my $os = $^O; # Protect $^O from tainting + + + # Try again to find a pwd, this time searching the whole PATH. + if (defined $ENV{PATH} and $os ne 'MSWin32') { # no pwd on Windows + my @candidates = split($sep, $ENV{PATH}); + while (!$found_pwd_cmd and @candidates) { + my $candidate = shift @candidates; + $found_pwd_cmd = 1 if -x "$candidate/pwd"; + } + } + + # MacOS has some special magic to make `pwd` work. + if( $os eq 'MacOS' || $found_pwd_cmd ) + { + *cwd = \&_backtick_pwd; + } + else { + *cwd = \&getcwd; + } +} + +if ($^O eq 'cygwin') { + # We need to make sure cwd() is called with no args, because it's + # got an arg-less prototype and will die if args are present. + local $^W = 0; + my $orig_cwd = \&cwd; + *cwd = sub { &$orig_cwd() } +} + + +# set a reasonable (and very safe) default for fastgetcwd, in case it +# isn't redefined later (20001212 rspier) +*fastgetcwd = \&cwd; + +# A non-XS version of getcwd() - also used to bootstrap the perl build +# process, when miniperl is running and no XS loading happens. +sub _perl_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; +} +if (not defined &fastcwd) { *fastcwd = \&fastcwd_ } + + +# Keeps track of current working directory in PWD environment var +# Usage: +# use Cwd 'chdir'; +# chdir $newdir; + +my $chdir_init = 0; + +sub chdir_init { + if ($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) { + $ENV{'PWD'} = cwd(); + } + } + else { + my $wd = cwd(); + $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; + $ENV{'PWD'} = $wd; + } + # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) + if ($^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) { + $ENV{'PWD'}="$2$3"; + } + } + $chdir_init = 1; +} + +sub chdir { + 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'} = $ENV{'DEFAULT'} + } + elsif ($^O eq 'MacOS') { + return $ENV{'PWD'} = cwd(); + } + elsif ($^O eq 'MSWin32') { + $ENV{'PWD'} = $newpwd; + return 1; + } + + if (ref $newdir eq 'GLOB') { # in case a file/dir handle is passed in + $ENV{'PWD'} = cwd(); + } elsif ($newdir =~ m#^/#s) { + $ENV{'PWD'} = $newdir; + } else { + my @curdir = split(m#/#,$ENV{'PWD'}); + @curdir = ('') unless @curdir; + my $component; + foreach $component (split(m#/#, $newdir)) { + next if $component eq '.'; + pop(@curdir),next if $component eq '..'; + push(@curdir,$component); + } + $ENV{'PWD'} = join('/',@curdir) || '/'; + } + 1; +} + + +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; + + # Can't use "-l _" here, because the previous stat was a stat(), not an lstat(). + if (-l $start) { + 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 $dir ? abs_path($dir) . "/$file" : "/$file"; + } + + $cwd = ''; + $dotdots = $start; + do + { + $dotdots .= '/..'; + @pst = @cst; + local *PARENT; + unless (opendir(PARENT, $dotdots)) + { + # probably a permissions issue. Try the native command. + return File::Spec->rel2abs( $start, _backtick_pwd() ); + } + unless (@cst = stat($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; +} + + +my $Curdir; +sub fast_abs_path { + local $ENV{PWD} = $ENV{PWD} || ''; # Guard against clobberage + my $cwd = getcwd(); + 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 $dir eq File::Spec->rootdir + ? File::Spec->catpath($vol, $dir, $file) + : fast_abs_path(File::Spec->catpath($vol, $dir, '')) . '/' . $file; + } + + if (!CORE::chdir($path)) { + _croak("Cannot chdir to $path: $!"); + } + my $realpath = getcwd(); + if (! ((-d $cwd) && (CORE::chdir($cwd)))) { + _croak("Cannot chdir back to $cwd: $!"); + } + $realpath; +} + +# added function alias to follow principle of least surprise +# based on previous aliasing. --tchrist 27-Jan-00 +*fast_realpath = \&fast_abs_path; + + +# --- PORTING SECTION --- + +# VMS: $ENV{'DEFAULT'} points to default directory at all times +# 06-Mar-1996 Charles Bailey bailey@newman.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 = shift; + + my $efs = _vms_efs; + my $unix_rpt = _vms_unix_rpt; + + if (defined &VMS::Filespec::vmsrealpath) { + my $path_unix = 0; + my $path_vms = 0; + + $path_unix = 1 if ($path =~ m#(?<=\^)/#); + $path_unix = 1 if ($path =~ /^\.\.?$/); + $path_vms = 1 if ($path =~ m#[\[<\]]#); + $path_vms = 1 if ($path =~ /^--?$/); + + my $unix_mode = $path_unix; + if ($efs) { + # In case of a tie, the Unix report mode decides. + if ($path_vms == $path_unix) { + $unix_mode = $unix_rpt; + } else { + $unix_mode = 0 if $path_vms; + } + } + + if ($unix_mode) { + # Unix format + return VMS::Filespec::unixrealpath($path); + } + + # VMS format + + my $new_path = VMS::Filespec::vmsrealpath($path); + + # Perl expects directories to be in directory format + $new_path = VMS::Filespec::pathify($new_path) if -d $path; + return $new_path; + } + + # Fallback to older algorithm if correct ones are not + # available. + + if (-l $path) { + my $link_target = readlink($path); + die "Can't resolve link $path: $!" unless defined $link_target; + + return _vms_abs_path($link_target); + } + + # may need to turn foo.dir into [.foo] + my $pathified = VMS::Filespec::pathify($path); + $path = $pathified if defined $pathified; + + return VMS::Filespec::rmsexpand($path); +} + +sub _os2_cwd { + $ENV{'PWD'} = `cmd /c cd`; + chomp $ENV{'PWD'}; + $ENV{'PWD'} =~ s:\\:/:g ; + return $ENV{'PWD'}; +} + +sub _win32_cwd { + if (eval 'defined &DynaLoader::boot_DynaLoader') { + $ENV{'PWD'} = Win32::GetCwd(); + } + else { # miniperl + chomp($ENV{'PWD'} = `cd`); + } + $ENV{'PWD'} =~ s:\\:/:g ; + return $ENV{'PWD'}; +} + +*_NT_cwd = defined &Win32::GetCwd ? \&_win32_cwd : \&_os2_cwd; + +sub _dos_cwd { + if (!defined &Dos::GetCwd) { + $ENV{'PWD'} = `command /c cd`; + chomp $ENV{'PWD'}; + $ENV{'PWD'} =~ s:\\:/:g ; + } else { + $ENV{'PWD'} = Dos::GetCwd(); + } + return $ENV{'PWD'}; +} + +sub _qnx_cwd { + local $ENV{PATH} = ''; + local $ENV{CDPATH} = ''; + local $ENV{ENV} = ''; + $ENV{'PWD'} = `/usr/bin/fullpath -t`; + chomp $ENV{'PWD'}; + return $ENV{'PWD'}; +} + +sub _qnx_abs_path { + local $ENV{PATH} = ''; + local $ENV{CDPATH} = ''; + local $ENV{ENV} = ''; + my $path = @_ ? shift : '.'; + local *REALPATH; + + defined( open(REALPATH, '-|') || exec '/usr/bin/fullpath', '-t', $path ) or + die "Can't open /usr/bin/fullpath: $!"; + my $realpath = <REALPATH>; + close REALPATH; + chomp $realpath; + return $realpath; +} + +sub _epoc_cwd { + $ENV{'PWD'} = EPOC::getcwd(); + return $ENV{'PWD'}; +} + + +# 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) { + local $^W = 0; # assignments trigger 'subroutine redefined' warning + no strict 'refs'; + *{$name} = \&{$map->{$name}}; + } +} + +# In case the XS version doesn't load. +*abs_path = \&_perl_abs_path unless defined &abs_path; +*getcwd = \&_perl_getcwd unless defined &getcwd; + +# added function alias for those of us more +# used to the libc function. --tchrist 27-Jan-00 +*realpath = \&abs_path; + +1; |