for $file(@ARGV)
{
    open(FHF,$file) or die("Can't open $file $!");
    while(<FHF>)
    {
        die "crap $file $!" unless ($verified);
    }
    close(FHF);
}

##</code><code>##

The null filehandle <> is special: it can be used to emulate the behavior of sed and awk. Input from <> comes either from standard input, or from each file listed on the command line. Here's how it works: the first time <> is evaluated, the @ARGV array is checked, and if it is empty, $ARGV[0] is set to ``-'', which when opened gives you standard input. The @ARGV array is then processed as a list of filenames. The loop


    while (<>) {

        ...                     # code for each line

    }
is equivalent to the following Perl-like pseudo code:


    unshift(@ARGV, '-') unless @ARGV;

    while ($ARGV = shift) {

        open(ARGV, $ARGV);

        while (<ARGV>) {

            ...         # code for each line

        }

    }