#!/usr/bin/perl -w

# scribbled by CBAS [ mailto:cbas@screaming3d.com ]
# 30/12/2000
#
# "One more kick to get me started ..."
#   - Republica

use strict;

use subs qw {
    doDir
    doFile
    freakOut
};

use vars qw {
    $from
    $into
    $recur
    $renamed
    $directories
    $argument
};

freakOut and exit unless @ARGV >= 4;

$renamed        = 0;
$directories    = 0;
$from            = shift @ARGV;
$into            = shift @ARGV;
$recur            = shift @ARGV;

print <<EOL;
Renaming files from "foo$from" to "foo$into" ...
EOL

for $argument ( @ARGV ) {
    print "WARNING: \"$argument\" could not be found as a directory.\n
+"
        unless -d $argument and doDir ( $argument );
}

print <<EOL;
Renamed $renamed file(s) in $directories directories.
EOL

sub doDir {
    my ( $dir, $foo, @fools );
    $dir = shift;
    opendir DIR, $dir or return 0;
    @fools = readdir DIR;
    closedir DIR;
    shift @fools; shift @fools;
    foreach $foo ( @fools ) {
        if ( $recur and -d "$dir/$foo" ) {
            doDir ( "$dir/$foo" );
        } elsif ( -f "$dir/$foo" and $foo =~ /$from$/ ) {
            doFile ( "$dir/$foo" );
        }
    }
    $directories++;
    return 1;
}

sub doFile {
    my ( $file, $temp );
    $file = shift;
    $temp = $file;
    $file =~ s/(.*)$from$/$1$into/;
    if ( rename $temp, $file ) {
        $renamed++
    } else {
        print "couldn't rename $temp: $!"
    }
}

sub freakOut {
    print <<EOL;
Usage:
    $0 from into recur dir [dir [dir ... ]

Where:
    from
        the file extension you want to change
    into
        to what you want to change from
    recur
        renaming will happen recursively when set to anything but 0
    dir
        directory that will be traversed by the script

Example:
    $0 .MP3 .mp3 1 .
EOL
}