Cwd(3)
NAME
Cwd - get pathname of current working directory
SYNOPSIS
use Cwd;
my $dir = getcwd;
use Cwd 'abs_path';
my $abs_path = abs_path($file);
DESCRIPTION
This module provides functions for determining the pathname of the cur-
rent working directory. It is recommended that getcwd (or another
*cwd() function) be used in all code to ensure portability.
By default, it exports the functions cwd(), getcwd(), fastcwd(), and
fastgetcwd() into the caller's namespace.
getcwd and friends
Each of these functions are called without arguments and return the
absolute path of the current working directory.
getcwd
my $cwd = getcwd();
Returns the current working directory.
Re-implements the getcwd(3) (or getwd(3)) functions in Perl.
Taint-safe.
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).
Taint-safe.
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 "die"
with the message "Unstable directory path, current directory
changed unexpectedly". That should never happen.
fastgetcwd
my $cwd = fastgetcwd();
The fastgetcwd() function is provided as a synonym for cwd().
abs_path and friends
These functions are exported only on request. They each take a single
argument and return the absolute pathname for it.
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).
Taint-safe.
realpath
my $abs_path = realpath($file);
A synonym for abs_path().
Taint-safe.
fast_abs_path
my $abs_path = fast_abs_path($file);
A more dangerous, but potentially faster version of abs_path.
This function is Not taint-safe : you can't use it in programs that
work under taint mode.
$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.
NOTES
o 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.
o Actually, on Mac OS, the "getcwd()", "fastgetcwd()" and "fastcwd()"
functions are all aliases for the "cwd()" function, which, on Mac
OS, calls `pwd`. Likewise, the "abs_path()" function is an alias
for "fast_abs_path()".
SEE ALSO
File::chdir
perl v5.8.0 2002-06-01 Cwd(3)
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