#!/usr/bin/perl
#
# PM_help.pl FileName - Prints contents of file FileName
# PM_help.pl -test    - Prints contents of <DATA> handle
# PM_help.pl          - Prints contents of STDIN
#
use strict;
use warnings;
use IO::Handle;

# Prepare the selected filehandle

my $FName=shift;
my $FH = new IO::Handle;
if (! defined $FName) {
    $FH->fdopen(fileno(STDIN), "r")
      or die "Can't grab STDIN!\nErrMsg: $!\n";
}
elsif ($FName eq "-test") {
    # I was hoping one of these two would work, but no luck
    #$FH->fdopen(fileno(DATA), "r")
    #  or die "Can't grab DATA!\nErrMsg: $!\n";
    #$FH->new_from_fd(fileno(DATA), "r")
    #  or die "Can't grab DATA!\nErrMsg: $!\n";

    # Works, but I don't care for it
    open $FH, '<', $0
      or die "Can't open '$0'\nErrMsg: $!\n";
    while (<$FH>) {
        last if /^__DATA__\s*$/;
    }
}
else {
    open $FH, '<', $FName
      or die "Can't open '$FName'\nErrMsg: $!\n";
}

# Use the file...

while (<$FH>) {
        print "$.: $_";
}

# EXAMPLE DATA
__DATA__
The quick red fox jumped over the lazy brown dog.
Now is the time for all good men to come to the aid of their party.