dos2unix perl script - convert line endings

I needed a quick utility to bulk convert dos line endings to unix format, and google failed me. So, I wrote this, and hopefully you have just won the google code-writing lottery:

#!/usr/bin/perl -w
#
#   Perl equivalent of the popular dos2unix utility:
#
#   Convert DOS line endings to Unix line endings:
#   works in bulk, safely updates files in place.
#
my  ($filename, $line, $count);
$count = 0;

#   If no arguments, print an error message
if( $#ARGV < 0 ) {
    print "Usage: $0 filenames\n";
    print ";Convert in place dos line endings to unix line endings\n";
    exit(5);
    }

#   Loop through each given filename
foreach $filename (@ARGV)
{
    if( -e "$filename.bak" ) {
        printf "Skipping $filename.bak - it already exists\n";
    }
    elsif(!( -f $filename && -r $filename && -w $filename  )) {
        printf "Skipping $filename - not a regular writable file\n";
    }
    else {
        rename("$filename","$filename.bak");
        open INPUT, "$filename.bak";
        open OUTPUT, ">$filename";

        while(  ) {
            s/\r\n$/\n/;        	# convert CR LF to LF (at end of line)
            print OUTPUT $_;
        }

        close INPUT;
        close OUTPUT;
        unlink("$filename.bak");	# remove old file only after new one is safe
        $count++;
    }
}
printf "Processed $count files.\n";

Written April 2006, by Bryce Nesbitt, www.obviously.com