%cat rename.pl
#!/usr/bin/perl

=head1 SYNOPSIS

rename.pl '<pattern from>/<pattern to>' <filenames>

=head1 DESCRIPTION

Renames the files listed as <filenames> after performing the substitution using the standard perl regular expression pattern from and to.

=head1 EXAMPLES

rename.pl 'ready/done' file1-ready file2-ready_to_go

renames "file1-ready" to "file1-done" and
        "file2-ready_to_go" to "file2-done_to_go"

=cut

use strict;
use warnings;

my $file;
my $old;
my $pattern;
my $command;
unless( @ARGV >= 2) {
        print "Usage: rename \"patternfrom/to\" <filenames>\n";
        exit(1);
} # end argument check

$pattern = shift(@ARGV);

foreach $file (@ARGV) {
        $old=$file;

        $pattern .= "/" unless( $pattern =~ m#.*?/.*?/$# );
        $command = "\$file =~ s/$pattern";

        eval $command;
        if ( $@ ) {
                print STDERR "$@";
        } # end eval failed check

        rename($old,$file);
} # end rename loop