You should really consult perlre for this. $ can match before a newline at the end of the string, whereas \z matches only at the absolute end of a string. If you have a file that ends in a newline, this is important.

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker.
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;