Simple Perl Code (Input REGEX, Search through files by that REGEX)

#!/usr/bin/perl
#perl-grep.pl

my $regex = shift @ARGV;

print "Regex is [$regex]\n";

while ( <> )
        {
        print if m/$regex/;
        }

[root@"+":/tmp]$ perl perl-grep.pl new *.pl
Regex is [new]
my $new_name = "$dirname/$basename";
rename ($old_name, $new_name)
 or warn "Can't rename '$old_name' to '$new_name': $!";
[root@"+":/tmp]$