use strict;    # Please do this!
use warnings;  # And this!

# First, read from the <DATA> filehandle to grab the list
# of banned words.  map the banned words into hash-keys.
my %banned = map { chomp $_; $_=> undef } split /\s+/, <DATA>;
my $infile = "textfile.txt";
my $tmpfile = "outfile.tmp";

open my $in, "<$infile" or die "Cannot open $infile.\n$!";
open my $out, ">$tmpfile" or die "Cannot open temp output file.\n$!";

while ( my $inline = <$in> ) {
	chomp $inline;
    my $printline = "";
	foreach my $word ( split /\s+/, $inline ) {
	    next if exists $banned{ lc $word };
	    $printline .= $word;
	}
	print $out "$printline\n";
}
	
close $out;
close $in;
rename $tmpfile, $infile;

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