X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCwd.pm;h=8b00543e1e9801a51f34472b36cad6f4c3dbfcea;hb=1a95e36d92295cabb6c213a2f397c4cb7614d12c;hp=16c5f07324d73d4db488f8e430841cf71ce3a79b;hpb=04929354e4af790d6b9d9b248b1d74e8ff8506df;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/Cwd.pm b/lib/Cwd.pm index 16c5f07..8b00543 100644 --- a/lib/Cwd.pm +++ b/lib/Cwd.pm @@ -1,5 +1,5 @@ package Cwd; -require 5.6.0; +use 5.006; =head1 NAME @@ -38,6 +38,8 @@ Returns the current working directory. Re-implements the getcwd(3) (or getwd(3)) functions in Perl. +Taint-safe. + =item cwd my $cwd = cwd(); @@ -46,7 +48,7 @@ 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. +Taint-safe. =item fastcwd @@ -87,18 +89,25 @@ Uses the same algorithm as getcwd(). Symbolic links and relative-path components ("." and "..") are resolved to return the canonical pathname, just like realpath(3). +Taint-safe. + =item realpath my $abs_path = realpath($file); A synonym for abs_path(). +Taint-safe. + =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. +This function is B taint-safe : you can't use it in programs +that work under taint mode. + =back =head2 $ENV{PWD} @@ -122,8 +131,6 @@ Since the path seperators are different on some operating systems ('/' on Unix, ':' on MacPerl, etc...) we recommend you use the File::Spec modules wherever portability is a concern. -=begin _private - =item * Actually, on Mac OS, the C, C and C @@ -131,8 +138,6 @@ functions are all aliases for the C function, which, on Mac OS, calls `pwd`. Likewise, the C function is an alias for C. -=end _private - =back =head1 SEE ALSO @@ -172,6 +177,7 @@ if ($^O eq 'os2' && defined &sys_cwd && defined &sys_abspath) { eval { require XSLoader; + undef *Cwd::fastcwd; # avoid redefinition warning XSLoader::load('Cwd'); }; @@ -190,7 +196,10 @@ $pwd_cmd ||= 'pwd'; # The 'natural and safe form' for UNIX (pwd may be setuid root) sub _backtick_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; $cwd; @@ -201,7 +210,9 @@ sub _backtick_pwd { unless(defined &cwd) { # The pwd command is not available in some chroot(2)'ed environments - if($^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 { @@ -222,6 +233,54 @@ 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'; @@ -292,6 +351,63 @@ 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; @@ -300,9 +416,10 @@ sub fast_abs_path { my $cwd = getcwd(); require File::Spec; my $path = @_ ? shift : File::Spec->curdir; - CORE::chdir($path) || croak "Cannot chdir to $path:$!"; + CORE::chdir($path) || croak "Cannot chdir to $path: $!"; my $realpath = getcwd(); - CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; + -d $cwd && CORE::chdir($cwd) || + croak "Cannot chdir back to $cwd: $!"; $realpath; } @@ -362,12 +479,18 @@ 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 $realpath; @@ -397,6 +520,7 @@ sub _epoc_cwd { *fastcwd = \&_NT_cwd; *fastgetcwd = \&_NT_cwd; *abs_path = \&fast_abs_path; + *realpath = \&fast_abs_path; } elsif ($^O eq 'os2') { # sys_cwd may keep the builtin command @@ -442,13 +566,5 @@ sub _epoc_cwd { } } -# 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";