/usr/share/perl5/File/Which.pm is in libfile-which-perl 1.09-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 | package File::Which;
use 5.004;
use strict;
use Exporter ();
use File::Spec ();
use vars qw{$VERSION @ISA @EXPORT @EXPORT_OK};
BEGIN {
$VERSION = '1.09';
@ISA = 'Exporter';
@EXPORT = 'which';
@EXPORT_OK = 'where';
}
use constant IS_VMS => ($^O eq 'VMS');
use constant IS_MAC => ($^O eq 'MacOS');
use constant IS_DOS => ($^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 @PATHEXT = ('');
if ( IS_DOS ) {
# WinNT. PATHEXT might be set on Cygwin, but not used.
if ( $ENV{PATHEXT} ) {
push @PATHEXT, split ';', $ENV{PATHEXT};
} else {
# Win9X or other: doesn't have PATHEXT, so needs hardcoded.
push @PATHEXT, qw{.com .exe .bat};
}
} elsif ( IS_VMS ) {
push @PATHEXT, qw{.exe .com};
}
sub which {
my ($exec) = @_;
return undef unless $exec;
my $all = wantarray;
my @results = ();
# check for aliases first
if ( IS_VMS ) {
my $symbol = `SHOW SYMBOL $exec`;
chomp($symbol);
unless ( $? ) {
return $symbol unless $all;
push @results, $symbol;
}
}
if ( IS_MAC ) {
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;
if ( IS_DOS or IS_VMS or IS_MAC ) {
unshift @path, File::Spec->curdir;
}
foreach my $base ( map { File::Spec->catfile($_, $exec) } @path ) {
for my $ext ( @PATHEXT ) {
my $file = $base.$ext;
# We don't want dirs (as they are -x)
next if -d $file;
if (
# Executable, normal case
-x _
or (
# MacOS doesn't mark as executable so we check -e
IS_MAC
||
(
IS_DOS
and
grep {
$file =~ /$_\z/i
} @PATHEXT[1..$#PATHEXT]
)
# 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 _
)
) {
return $file unless $all;
push @results, $file;
}
}
}
if ( $all ) {
return @results;
} else {
return undef;
}
}
sub where {
# force wantarray
my @res = which($_[0]);
return @res;
}
1;
__END__
=pod
=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 $exe_path = which('perldoc');
my @paths = where('perl');
- Or -
my @paths = which('perl'); # an array forces search for all of them
=head1 DESCRIPTION
C<File::Which> was created to be able to get the paths to executable programs
on systems under which the `which' program wasn't implemented in the shell.
C<File::Which> searches the directories of the user's C<PATH> (as returned by
C<File::Spec-E<gt>path()>), looking for executable files having the name
specified as a parameter to C<which()>. Under Win32 systems, which do not have a
notion of directly executable files, but uses special extensions such as C<.exe>
and C<.bat> to identify them, C<File::Which> takes extra steps to assure that
you will find the correct file (so for example, you might be searching for
C<perl>, it'll try F<perl.exe>, F<perl.bat>, etc.)
=head1 Steps Used on Win32, DOS, OS2 and VMS
=head2 Windows NT
Windows NT has a special environment variable called C<PATHEXT>, which is used
by the shell to look for executable files. Usually, it will contain a list in
the form C<.EXE;.BAT;.COM;.JS;.VBS> etc. If C<File::Which> finds such an
environment variable, it parses the list and uses it as the different
extensions.
=head2 Windows 9x and other ancient Win/DOS/OS2
This set of operating systems don't have the C<PATHEXT> variable, and usually
you will find executable files there with the extensions C<.exe>, C<.bat> and
(less likely) C<.com>. C<File::Which> uses this hardcoded list if it's running
under Win32 but does not find a C<PATHEXT> variable.
=head2 VMS
Same case as Windows 9x: uses C<.exe> and C<.com> (in that order).
=head1 Functions
=head2 which($short_exe_name)
Exported by default.
C<$short_exe_name> is the name used in the shell to call the program (for
example, C<perl>).
If it finds an executable with the name you specified, C<which()> will return
the absolute path leading to this executable (for example, F</usr/bin/perl> or
F<C:\Perl\Bin\perl.exe>).
If it does I<not> find the executable, it returns C<undef>.
If C<which()> is called in list context, it will return I<all> the
matches.
=head2 where($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 SUPPORT
Bugs should be reported via the CPAN bug tracker at
L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=File-Which>
For other issues, contact the maintainer.
=head1 AUTHOR
Adam Kennedy E<lt>adamk@cpan.orgE<gt>
Per Einar Ellefsen E<lt>pereinar@cpan.orgE<gt>
Originated in F<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
L<http://www.perl.com/language/ppt/src/which/index.html> for more
information.
=head1 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.
=head1 SEE ALSO
L<File::Spec>, L<which(1)>, Perl Power Tools:
L<http://www.perl.com/language/ppt/index.html>.
=cut
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