NAME
    File::Which - Portable implementation of the `which' utility

SYNOPSIS
      use File::Which;                  # exports which()
      use File::Which qw(which where);  # exports which() and where()
      
  my $exe_path = which('perldoc');
      
  my @paths = where('perl');
      - Or -
      my @paths = which('perl'); # an array forces search for all of them

DESCRIPTION
    "File::Which" was created to be able to get the paths to executable
    programs on systems under which the `which' program wasn't implemented
    in the shell.

    "File::Which" searches the directories of the user's "PATH" (as returned
    by "File::Spec->path()"), looking for executable files having the name
    specified as a parameter to "which()". Under Win32 systems, which do not
    have a notion of directly executable files, but uses special extensions
    such as ".exe" and ".bat" to identify them, "File::Which" takes extra
    steps to assure that you will find the correct file (so for example, you
    might be searching for "perl", it'll try perl.exe, perl.bat, etc.)

Steps Used on Win32, DOS, OS2 and VMS
  Windows NT
    Windows NT has a special environment variable called "PATHEXT", which is
    used by the shell to look for executable files. Usually, it will contain
    a list in the form ".EXE;.BAT;.COM;.JS;.VBS" etc. If "File::Which" finds
    such an environment variable, it parses the list and uses it as the
    different extensions.

  Windows 9x and other ancient Win/DOS/OS2
    This set of operating systems don't have the "PATHEXT" variable, and
    usually you will find executable files there with the extensions ".exe",
    ".bat" and (less likely) ".com". "File::Which" uses this hardcoded list
    if it's running under Win32 but does not find a "PATHEXT" variable.

  VMS
    Same case as Windows 9x: uses ".exe" and ".com" (in that order).

Functions
  which($short_exe_name)
    Exported by default.

    $short_exe_name is the name used in the shell to call the program (for
    example, "perl").

    If it finds an executable with the name you specified, "which()" will
    return the absolute path leading to this executable (for example,
    /usr/bin/perl or C:\Perl\Bin\perl.exe).

    If it does *not* find the executable, it returns "undef".

    If "which()" is called in list context, it will return *all* the
    matches.

  where($short_exe_name)
    Not exported by default.

    Same as "which($short_exe_name)" in array context. Same as the `where'
    utility, will return an array containing all the path names matching
    $short_exe_name.

BUGS AND CAVEATS
    Not tested on VMS or MacOS, although there is platform specific code for
    those. Anyone who haves a second would be very kind to send me a report
    of how it went.

    File::Spec adds the current directory to the front of PATH if on Win32,
    VMS or MacOS. I have no knowledge of those so don't know if the current
    directory is searced first or not. Could someone please tell me?

SUPPORT
    Bugs should be reported via the CPAN bug tracker at

    <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=File-Which>

    For other issues, contact the maintainer.

AUTHOR
    Adam Kennedy <adamk@cpan.org>

    Per Einar Ellefsen <pereinar@cpan.org>

    Originated in modperl-2.0/lib/Apache/Build.pm. Changed for use in DocSet
    (for the mod_perl site) and Win32-awareness by me, with slight
    modifications by Stas Bekman, then extracted to create "File::Which".

    Version 0.04 had some significant platform-related changes, taken from
    the Perl Power Tools `which' implementation by Abigail with enhancements
    from Peter Prymmer. See
    <http://www.perl.com/language/ppt/src/which/index.html> for more
    information.

COPYRIGHT
    Copyright 2002 Per Einar Ellefsen.

    Some parts copyright 2009 Adam Kennedy.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

SEE ALSO
    File::Spec, which(1), Perl Power Tools:
    <http://www.perl.com/language/ppt/index.html>.