Is there a way around grep?

[mdegges]

Hi guys, I'm a new perl user, and have been working on a perl web crawler for a couple weeks now. A few days ago I was really stuck on the normalize url part, so I showed my friend my code and asked him if he had any ideas. He emailed me back with the if(grep..) part down to the bottom.. but I have no idea what it's doing. I know grep's in the format {expr} stack and filters through the stack, but I'm still confused about it and want to understand. I think it might actually be better to just not use grep altogether, but is there a way of doing that?

use File::Basename;

#list of filenames to normalize
my @index_file_names=qw(index.html index.htm index.php index.asp index
+.cgi);


sub normalize_url {
    my $old_url = $_[0];
    chomp($old_url);
    #saves name at the end 
    my $filename=basename($old_url);

    if (grep {$_ eq $filename} @index_file_names) {
    #saves the directory part
    my $normalized_url=dirname($old_url);
    $normalized_url;
    }else{
        #don't need to normalize url
    $old_url; 
    }
}

Thanks for any help!