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add File::Which 0.05 to lib

git-svn-id: https://svn.parrot.org/parrot/trunk@9959 d31e2699-5ff4-0310-a27c-f18f2fbe73fe
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1 parent 9a6729b commit b569eb1b952e7471637b0cc1fce33f9beb8eb8fd @jhoblitt jhoblitt committed Nov 14, 2005
Showing with 226 additions and 0 deletions.
  1. +1 −0 MANIFEST
  2. +225 −0 lib/File/Which.pm
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1 MANIFEST
@@ -1579,6 +1579,7 @@ languages/urm/urm-old.pl [urm]
languages/urm/urmc [urm]
lib/Class/Struct.pm [devel]
lib/Digest/Perl/MD5.pm [devel]
+lib/File/Which.pm [devel]
lib/Parrot/BuildUtil.pm [devel]
lib/Parrot/Configure/Data.pm [devel]
lib/Parrot/Configure/RunSteps.pm [devel]
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225 lib/File/Which.pm
@@ -0,0 +1,225 @@
+package File::Which;
+
+use strict;
+
+require Exporter;
+
+@File::Which::ISA = qw(Exporter);
+
+@File::Which::EXPORT = qw(which);
+@File::Which::EXPORT_OK = qw(where);
+
+$File::Which::VERSION = '0.05';
+
+use File::Spec;
+
+my $Is_VMS = ($^O eq 'VMS');
+my $Is_MacOS = ($^O eq 'MacOS');
+my $Is_DOSish = (($^O eq 'MSWin32') or
+ ($^O eq 'dos') or
+ ($^O eq 'os2'));
+
+# For Win32 systems, stores the extensions used for
+# executable files
+# For others, the empty string is used
+# because 'perl' . '' eq 'perl' => easier
+my @path_ext = ('');
+if ($Is_DOSish) {
+ if ($ENV{PATHEXT} and $Is_DOSish) { # WinNT. PATHEXT might be set on Cygwin, but not used.
+ push @path_ext, split ';', $ENV{PATHEXT};
+ }
+ else {
+ push @path_ext, qw(.com .exe .bat); # Win9X or other: doesn't have PATHEXT, so needs hardcoded.
+ }
+}
+elsif ($Is_VMS) {
+ push @path_ext, qw(.exe .com);
+}
+
+sub which {
+ my ($exec) = @_;
+
+ return undef unless $exec;
+
+ my $all = wantarray;
+ my @results = ();
+
+ # check for aliases first
+ if ($Is_VMS) {
+ my $symbol = `SHOW SYMBOL $exec`;
+ chomp($symbol);
+ if (!$?) {
+ return $symbol unless $all;
+ push @results, $symbol;
+ }
+ }
+ if ($Is_MacOS) {
+ my @aliases = split /\,/, $ENV{Aliases};
+ foreach my $alias (@aliases) {
+ # This has not been tested!!
+ # PPT which says MPW-Perl cannot resolve `Alias $alias`,
+ # let's just hope it's fixed
+ if (lc($alias) eq lc($exec)) {
+ chomp(my $file = `Alias $alias`);
+ last unless $file; # if it failed, just go on the normal way
+ return $file unless $all;
+ push @results, $file;
+ # we can stop this loop as if it finds more aliases matching,
+ # it'll just be the same result anyway
+ last;
+ }
+ }
+ }
+
+ my @path = File::Spec->path();
+ unshift @path, File::Spec->curdir if $Is_DOSish or $Is_VMS or $Is_MacOS;
+
+ for my $base (map { File::Spec->catfile($_, $exec) } @path) {
+ for my $ext (@path_ext) {
+ my $file = $base.$ext;
+# print STDERR "$file\n";
+
+ if ((-x $file or # executable, normal case
+ ($Is_MacOS || # MacOS doesn't mark as executable so we check -e
+ ($Is_DOSish and grep { $file =~ /$_$/i } @path_ext[1..$#path_ext])
+ # DOSish systems don't pass -x on non-exe/bat/com files.
+ # so we check -e. However, we don't want to pass -e on files
+ # that aren't in PATHEXT, like README.
+ and -e _)
+ ) and !-d _)
+ { # and finally, we don't want dirs to pass (as they are -x)
+
+# print STDERR "-x: ", -x $file, " -e: ", -e _, " -d: ", -d _, "\n";
+
+ return $file unless $all;
+ push @results, $file; # Make list to return later
+ }
+ }
+ }
+
+ if($all) {
+ return @results;
+ } else {
+ return undef;
+ }
+}
+
+sub where {
+ my @res = which($_[0]); # force wantarray
+ return @res;
+}
+
+1;
+__END__
+
+=head1 NAME
+
+File::Which - Portable implementation of the `which' utility
+
+=head1 SYNOPSIS
+
+ use File::Which; # exports which()
+ use File::Which qw(which where); # exports which() and where()
+
+ my $exe_path = which('perldoc');
+
+ my @paths = where('perl');
+ - Or -
+ my @paths = which('perl'); # an array forces search for all of them
+
+=head1 DESCRIPTION
+
+C<File::Which> was created to be able to get the paths to executable programs
+on systems under which the `which' program wasn't implemented in the shell.
+
+C<File::Which> searches the directories of the user's C<PATH> (as returned by
+C<File::Spec-E<gt>path()>), looking for executable files having the name specified
+as a parameter to C<which()>. Under Win32 systems, which do not have a notion of
+directly executable files, but uses special extensions such as C<.exe> and
+C<.bat> to identify them, C<File::Which> takes extra steps to assure that you
+will find the correct file (so for example, you might be searching for C<perl>,
+it'll try C<perl.exe>, C<perl.bat>, etc.)
+
+=head1 Steps Used on Win32, DOS, OS2 and VMS
+
+=head2 Windows NT
+
+Windows NT has a special environment variable called C<PATHEXT>, which is used
+by the shell to look for executable files. Usually, it will contain a list in
+the form C<.EXE;.BAT;.COM;.JS;.VBS> etc. If C<File::Which> finds such an
+environment variable, it parses the list and uses it as the different extensions.
+
+=head2 Windows 9x and other ancient Win/DOS/OS2
+
+This set of operating systems don't have the C<PATHEXT> variable, and usually
+you will find executable files there with the extensions C<.exe>, C<.bat> and
+(less likely) C<.com>. C<File::Which> uses this hardcoded list if it's running
+under Win32 but does not find a C<PATHEXT> variable.
+
+=head2 VMS
+
+Same case as Windows 9x: uses C<.exe> and C<.com> (in that order).
+
+=head1 Functions
+
+=head2 which($short_exe_name)
+
+Exported by default.
+
+C<$short_exe_name> is the name used in the shell to call the program (for
+example, C<perl>).
+
+If it finds an executable with the name you specified, C<which()> will return
+the absolute path leading to this executable (for example, C</usr/bin/perl> or
+C<C:\Perl\Bin\perl.exe>).
+
+If it does I<not> find the executable, it returns C<undef>.
+
+If C<which()> is called in list context, it will return I<all> the
+matches.
+
+=head2 where($short_exe_name)
+
+Not exported by default.
+
+Same as C<which($short_exe_name)> in array context. Same as the
+C<`where'> utility, will return an array containing all the path names
+matching C<$short_exe_name>.
+
+
+=head1 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?
+
+=head1 Author
+
+Per Einar Ellefsen, E<lt>per.einar (at) skynet.beE<gt>
+
+Originated in I<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 C<File::Which>.
+
+Version 0.04 had some significant platform-related changes, taken from
+the Perl Power Tools C<`which'> implementation by Abigail with
+enhancements from Peter Prymmer. See
+http://www.perl.com/language/ppt/src/which/index.html for more
+information.
+
+=head1 License
+
+This library is free software; you can redistribute it and/or modify it under
+the same terms as Perl itself.
+
+=head1 See Also
+
+L<File::Spec>, L<which(1)>, Perl Power Tools:
+http://www.perl.com/language/ppt/index.html .
+
+=cut

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