#!/usr/bin/perl -s
##
## pev -- Perl Extension Version. 
## 
## Reports the installation status and version of a Perl Extension Module (.pm) 
##
## Copyright (c) 1999-2000, Vipul Ved Prakash.  All rights reserved.
## This code is free software; you can redistribute it and/or modify
## it under the same terms as Perl itself.
##
## $Id$

use Data::Dumper; 

my $class = shift || die "syntax: pev [-f] [-v] [-vv] modulename\n";
$module = $class; $module =~ s#::#/#g; $module = "$module.pm";
eval { require $module } || die "$class not installed.\n";
eval { $version  = $class->VERSION } || print "Version information not available for "; 
print "$class $version\n"; 

$v = 1 if defined $vv; my (@PM, @STAT) if $v; 

if ( $f ) { print "[$INC{$module}]\n" } 

if ( $v ) { 

    my $file = $INC{$module};
    print "\nFilename\n\t$file\n";

    open PM, $file || die $!;
    @PM = <PM>; @STAT = stat( PM );  
    close PM;

    $proc = depends_on ( \@PM ); 
    $auth = author ( \@PM );

    print "Size\n\t$#PM lines"; 
    print ", $STAT[7] bytes" if $vv; print "\n"; $"="\n\t"; 
    print "Dependencies\n\t@$proc\n";
    print "Author\n\t$auth\n";
    print "Installation\n\t" . localtime($STAT[9]) . "\n" if $vv;

}


sub depends_on { 

    my @mods; 
    grep {s/^\s*(?:require|use)\s+(\S+)\s*;\s*$/$1/i && push @mods,$1}@{$_[0]};
    return \@mods;

}


sub author { 

    my ( $author ) = (join '', @{$_[0]}) =~ m/^\=head1\s+AUTHORS?\s*\n\n\s*?(.*?)\n/ims;
    $author = "Author name not available." unless $author; 
    $author =~ s/^\s*//; $author=~ s/I<(.*?)>/$1/; 
    return $author; 

}


"True Value";

=head1 NAME

pev - report perl extension installation status and version.

=head1 SYNOPSIS

    pev Digest::MD5
    pev -v Text::Template
    pev -f Carp 
    pev -vv Crypt::Random 

=head1 DESCRIPTION

pev extracts and reports metadata from installed perl modules.  `installed'
means any module visible to the perl interpreter on your machine, i.e.
under one of the directories in @INC as compiled in lib_perl.  perl C<-V>
lists these directories.

Without options, pev reports the version number of specified perl module, or
a "not installed" error message.  C<-v> additionally reports complete
pathname of the .pm file that contains the module, size of this file in
lines, dependencies (the modules included with use/require statements) and
name/email of the author.  C<-vv> makes C<-v> more verbose.  C<-f> reports
just the pathname.

=head1 AUTHOR

Vipul Ved Prakash, I<mail@vipul.net>

=cut