Using perl Syntax Highlighting
# 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;
}
#
# 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;
}
Coloreado en 0.004 segundos, usando GeSHi 1.0.8.4
Eso es de Cwd.pm
¿Cómo funciona? (no lo entiendo).
¿Cómo puede dar el path con sólo ver los inodos y los dev?
Gracias.
