#!/usr/bin/perl -w
use strict;

die "$0 <source> <target> ..." unless @ARGV > 1;
my %keyword = ();

my ( $source, @targets ) = @ARGV;

my $package = '';
#---
# Try to extract the keywords, precompile the regex and store
#---
open SRC, $source or die "Couldn't open $source : $!";
while( <SRC> ) {
    $package = $1 if ( ! $package && /^package\s+(.+);/ );
    next unless ( /^sub\s+(.+){\s*$/ );

    my $name;
    $name = $1;
    next if ( substr($name,0,1) eq "_" );

    $name =~ s/\s+$//;
    $keyword{$name} = qr/([\w:{}]+)->$name/;
}
close SRC;

for my $file ( @targets ) {
    my ( $line );

    open FILE, $file or die "Couldn't open $file : $!";

    LINE:
        while( $line = <FILE> ) {
            next LINE if ( $line =~ /^\s*#/ || $line =~ /^\s*$/ );
            last LINE if $line =~ /__END__/;


            for ( keys %keyword ) {
                my $regex = $keyword{$_};
                if ( $line =~ /$regex/ ) {
                    my $starts_at = $.;
                    my $lpack = $1 || '';

                    next LINE if ( $file eq $source ) && ( $line =~ /^sub/ );
                    next LINE if ( $line =~ /Usage/ );
                    next LINE if ( $lpack =~ /::/ && $lpack ne $package );

                    while( $line !~ /;/ && ! eof(FILE) ) {
                        $line .= <FILE>;
                        next LINE if $line =~ /^EOF/m;
                    }
                    $line =~ s/^\s*//;
                    printf "%s (%d) %s", uc $file, $starts_at, $line;
                    next LINE;
                }
            }
        }
    #LINE
    close FILE;
}