Index for Section 3

Alphabetical listing for C

Bottom of page

Cwd(3)
NAME
  Cwd - get pathname of current working directory

SYNOPSIS
      use Cwd;
      $dir = cwd;

      use Cwd;
      $dir = getcwd;

      use Cwd;
      $dir = fastcwd;

      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'});

DESCRIPTION
  This module provides functions for determining the pathname of the current
  working directory.  By default, it exports the functions cwd(), getcwd(),
  fastcwd(), and fastgetcwd() into the caller's namespace.  Each of these
  functions are called without arguments and return the absolute path of the
  current working directory.  It is recommended that cwd (or another *cwd()
  function) be used in all code to ensure portability.

  The cwd() is the most natural and safe form for the current architecture.
  For most systems it is identical to `pwd` (but without the trailing line
  terminator).

  The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions
  in Perl.

  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 "die" with the
  message "Unstable directory path, current directory changed unexpectedly".
  That should never happen.

  The fastgetcwd() function is provided as a synonym for cwd().

  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).  This function is also callable as realpath().

  The fast_abs_path() function looks the same as abs_path() but runs faster
  and, like fastcwd(), is more dangerous.

  If you ask to override your chdir() built-in function, then your PWD
  environment variable will be kept up to date.	 (See the Overriding Builtin
  Functions entry in the perlsub manpage.) Note that it will only be kept up
  to date if all packages which use chdir import it from Cwd.

Index for Section 3

Alphabetical listing for C

Top of page