In this case, think of
grep as a
for loop. It loops through all 5 of the filenames in your array variable (@index_file_names). For each filename ($_), it compares against the $filename value. If they are equivalent, an internal counter is incremented.
grep returns the number of matches. If at least one match occured, the
if clause is executed.
use File::Basename;
#list of filenames to normalize
my @index_file_names=qw(index.html index.htm index.php index.asp index
+.cgi);
normalize_url('foo');
normalize_url('bar/index.php');
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);
#$normalized_url;
print "$old_url: found\n";
}else{
#don't need to normalize url
#$old_url;
print "$old_url: not found\n";
}
}
__END__
foo: not found
bar/index.php: found
This is a common use of
grep.
