X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCwd.pm;h=eb337b40e0d1efaaa7417412d726b209a08868af;hb=ac83e8b044590bc6622a16582bca511edfc55703;hp=b27e0888479c17f0c9b38e6771af8c097cc3b054;hpb=40000a8c37c35cc00114329ca0add46bca36a0ec;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/Cwd.pm b/lib/Cwd.pm index b27e088..eb337b4 100644 --- a/lib/Cwd.pm +++ b/lib/Cwd.pm @@ -1,10 +1,95 @@ package Cwd; require 5.000; -require Exporter; -@ISA = qw(Exporter); -@EXPORT = qw(getcwd fastcwd); -@EXPORT_OK = qw(chdir); +=head1 NAME + +getcwd - get pathname of current working directory + +=head1 SYNOPSIS + + use Cwd; + $dir = cwd; + + use Cwd; + $dir = getcwd; + + use Cwd; + $dir = fastgetcwd; + + use Cwd 'chdir'; + chdir "/tmp"; + print $ENV{'PWD'}; + + use Cwd 'abs_path'; # aka realpath() + print abs_path($ENV{'PWD'}); + + use Cwd 'fast_abs_path'; + print fast_abs_path($ENV{'PWD'}); + +=head1 DESCRIPTION + +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. + +=cut + +use strict; + +use Carp; + +our $VERSION = '2.03'; + +use base qw/ Exporter /; +our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); +our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); + + +# The 'natural and safe form' for UNIX (pwd may be setuid root) + +sub _backtick_pwd { + my $cwd = `pwd`; + # `pwd` may fail e.g. if the disk is full + chomp($cwd) if defined $cwd; + $cwd; +} + +# Since some ports may predefine cwd internally (e.g., NT) +# we take care not to override an existing definition for cwd(). + +*cwd = \&_backtick_pwd unless defined &cwd; # By Brandon S. Allbery @@ -13,125 +98,78 @@ require Exporter; sub getcwd { - my($dotdots, $cwd, @pst, @cst, $dir, @tst); - - unless (@cst = stat('.')) - { - warn "stat(.): $!"; - return ''; - } - $cwd = ''; - $dotdots = ''; - do - { - $dotdots .= '/' if $dotdots; - $dotdots .= '..'; - @pst = @cst; - unless (opendir(PARENT, $dotdots)) - { - warn "opendir($dotdots): $!"; - return ''; - } - unless (@cst = stat($dotdots)) - { - warn "stat($dotdots): $!"; - closedir(PARENT); - return ''; - } - if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) - { - $dir = ''; - } - else - { - do - { - unless (defined ($dir = readdir(PARENT))) - { - warn "readdir($dotdots): $!"; - closedir(PARENT); - return ''; - } - unless (@tst = lstat("$dotdots/$dir")) - { - warn "lstat($dotdots/$dir): $!"; - closedir(PARENT); - return ''; - } - } - while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || - $tst[1] != $pst[1]); - } - $cwd = "$dir/$cwd"; - closedir(PARENT); - } while ($dir); - chop($cwd); # drop the trailing / - $cwd; + 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, $path); local(*DIR); - ($cdev, $cino) = stat('.'); + my($orig_cdev, $orig_cino) = stat('.'); + ($cdev, $cino) = ($orig_cdev, $orig_cino); for (;;) { my $direntry; ($odev, $oino) = ($cdev, $cino); - chdir('..'); + CORE::chdir('..') || return undef; ($cdev, $cino) = stat('.'); last if $odev == $cdev && $oino == $cino; - opendir(DIR, '.'); + opendir(DIR, '.') || return undef; for (;;) { $direntry = readdir(DIR); + last unless defined $direntry; next if $direntry eq '.'; next if $direntry eq '..'; - last unless defined $direntry; ($tdev, $tino) = lstat($direntry); last unless $tdev != $odev || $tino != $oino; } closedir(DIR); + return undef unless defined $direntry; # should never happen unshift(@path, $direntry); } - chdir($path = '/' . join('/', @path)); + $path = '/' . join('/', @path); + if ($^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 -# -# $RCSfile: pwd.pl,v $$Revision: 4.1 $$Date: 92/08/07 18:24:11 $ -# -# $Log: pwd.pl,v $ -# +# Keeps track of current working directory in PWD environment var # Usage: # use Cwd 'chdir'; # chdir $newdir; -$chdir_init = 0; +my $chdir_init = 0; -sub chdir_init{ - if ($ENV{'PWD'}) { +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 != $pd) { - chop($ENV{'PWD'} = `pwd`); + $ENV{'PWD'} = cwd(); } } else { - chop($ENV{'PWD'} = `pwd`); + my $wd = cwd(); + $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; + $ENV{'PWD'} = $wd; } - if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|) { + # 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 == $pd) { @@ -142,14 +180,24 @@ sub chdir_init{ } sub chdir { - my($newdir) = shift; + my $newdir = @? ? shift : ''; # allow for no arg (chdir to HOME dir) + $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; chdir_init() unless $chdir_init; - return 0 unless (CORE::chdir $newdir); - if ($newdir =~ m#^/#) { + return 0 unless CORE::chdir $newdir; + if ($^O eq 'VMS') { + return $ENV{'PWD'} = $ENV{'DEFAULT'} + } + elsif ($^O eq 'MSWin32') { + $ENV{'PWD'} = Win32::GetFullPathName($newdir); + return 1; + } + + if ($newdir =~ m#^/#s) { $ENV{'PWD'} = $newdir; - }else{ - my(@curdir) = split(m#/#,$ENV{'PWD'}); - @curdir = '' unless @curdir; + } 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 '..'; @@ -157,7 +205,204 @@ sub chdir { } $ENV{'PWD'} = join('/',@curdir) || '/'; } + 1; +} + +# Taken from Cwd.pm It is really getcwd with an optional +# parameter instead of '.' +# + +sub 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; + +sub fast_abs_path { + my $cwd = getcwd(); + my $path = @_ ? shift : '.'; + CORE::chdir($path) || croak "Cannot chdir to $path:$!"; + my $realpath = getcwd(); + CORE::chdir($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 $path = VMS::Filespec::pathify($_[0]); + croak("Invalid path name $_[0]") unless defined $path; + return VMS::Filespec::rmsexpand($path); +} + +sub _os2_cwd { + $ENV{'PWD'} = `cmd /c cd`; + chop $ENV{'PWD'}; + $ENV{'PWD'} =~ s:\\:/:g ; + return $ENV{'PWD'}; +} + +sub _win32_cwd { + $ENV{'PWD'} = Win32::GetCwd(); + $ENV{'PWD'} =~ s:\\:/:g ; + return $ENV{'PWD'}; +} + +*_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && + defined &Win32::GetCwd); + +*_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; + +sub _dos_cwd { + if (!defined &Dos::GetCwd) { + $ENV{'PWD'} = `command /c cd`; + chop $ENV{'PWD'}; + $ENV{'PWD'} =~ s:\\:/:g ; + } else { + $ENV{'PWD'} = Dos::GetCwd(); + } + return $ENV{'PWD'}; +} + +sub _qnx_cwd { + $ENV{'PWD'} = `/usr/bin/fullpath -t`; + chop $ENV{'PWD'}; + return $ENV{'PWD'}; +} + +sub _qnx_abs_path { + my $path = @_ ? shift '.'; + my $realpath=`/usr/bin/fullpath -t $path`; + chop $realpath; + return $realpath; } +{ + no warnings; # assignments trigger 'subroutine redefined' warning + + if ($^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; + } +} + +# 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";