#!/usr/bin/env perl
# pmload -- show what files a module loads
# tchrist@perl.com
BEGIN { $^W = 1 }
BEGIN { die "usage: $0 module\n" unless @ARGV == 1 }
%seen = %INC;
$module = shift;
eval "local \$^W = 0; require $module";
if ($@) {
$@ =~ s/at \(eval.*$//;
die "$0: $@";
}
for $path (values %INC) {
print "$path\n" unless $seen{$path};
}
__END__
=head1 NAME
pmload - show what files a given module loads at compile time
=head1 DESCRIPTION
Given an argument of a module name, show all the files
that are loaded directly or indirectly when the module
is used at compile-time.
=head1 EXAMPLES
$ pmload IO::Handle
/usr/local/devperl/lib/5.00554/Exporter.pm
/usr/local/devperl/lib/5.00554/Carp.pm
/usr/local/devperl/lib/5.00554/strict.pm
/usr/local/devperl/lib/5.00554/vars.pm
/usr/local/devperl/lib/5.00554/i686-linux/DynaLoader.pm
/usr/local/devperl/lib/5.00554/i686-linux/IO/Handle.pm
/usr/local/devperl/lib/5.00554/Symbol.pm
/usr/local/devperl/lib/5.00554/i686-linux/IO/File.pm
/usr/local/devperl/lib/5.00554/SelectSaver.pm
/usr/local/devperl/lib/5.00554/i686-linux/Fcntl.pm
/usr/local/devperl/lib/5.00554/AutoLoader.pm
/usr/local/devperl/lib/5.00554/i686-linux/IO.pm
/usr/local/devperl/lib/5.00554/i686-linux/IO/Seekable.pm
$ cat `pmload IO::Socket` | wc -l
4015
$ oldperl -S pmload Tk
/usr/lib/perl5/site_perl/Tk/Pretty.pm
/usr/lib/perl5/Symbol.pm
/usr/lib/perl5/site_perl/Tk/Frame.pm
/usr/lib/perl5/site_perl/Tk/Toplevel.pm
/usr/lib/perl5/strict.pm
/usr/lib/perl5/Exporter.pm
/usr/lib/perl5/vars.pm
/usr/lib/perl5/site_perl/auto/Tk/Wm/autosplit.ix
/usr/lib/perl5/site_perl/auto/Tk/Widget/autosplit.ix
/usr/lib/perl5/site_perl/Tk.pm
/usr/lib/perl5/i386-linux/5.00404/DynaLoader.pm
/usr/lib/perl5/site_perl/auto/Tk/Frame/autosplit.ix
/usr/lib/perl5/site_perl/auto/Tk/Toplevel/autosplit.ix
/usr/lib/perl5/Carp.pm
/usr/lib/perl5/site_perl/auto/Tk/autosplit.ix
/usr/lib/perl5/site_perl/Tk/CmdLine.pm
/usr/lib/perl5/site_perl/Tk/MainWindow.pm
/usr/lib/perl5/site_perl/Tk/Submethods.pm
/usr/lib/perl5/site_perl/Tk/Configure.pm
/usr/lib/perl5/AutoLoader.pm
/usr/lib/perl5/site_perl/Tk/Derived.pm
/usr/lib/perl5/site_perl/Tk/Image.pm
/usr/lib/perl5/site_perl/Tk/Wm.pm
/usr/lib/perl5/site_perl/Tk/Widget.pm
=head1 NOTE
If the programmers used a delayed C<require>, those files won't show up.
Furthermore, this doesn't show all possible files that get opened,
just those that those up in %INC. Most systems have a way to trace
system calls. You can use this to find the real answer. First, get a
baseline with no modules loaded.
$ strace perl -e 1 2>&1 | perl -nle '/^open\("(.*?)".* = [^-]/ && print $1'
/etc/ld.so.cache
/lib/libnsl.so.1
/lib/libdb.so.2
/lib/libdl.so.2
/lib/libm.so.6
/lib/libc.so.6
/lib/libcrypt.so.1
/dev/null
$ strace perl -e 1 2>&1 | grep -c '^open.*= [^-]'
8
Now add module loads and see what you get:
$ strace perl -MIO::Socket -e 1 2>&1 | grep -c '^open.*= [^-]'
24
$ strace perl -MTk -e 1 2>&1 | grep -c '^open.*= [^-]'
35
=head1 SEE ALSO
Devel::Loaded, plxload(1).
=head1 AUTHOR and COPYRIGHT
Copyright (c) 1999 Tom Christiansen
This is free software. You may modify it and distribute it
under Perl's Artistic Licence. Modified versions must be
clearly indicated.