use strict;

open (INFILE, $ARGV[0]) or die "Unable to open file '$ARGV[0]' - $!";
while(<INFILE>) {
	print replace($_);
}
close (INFILE);

sub replace {
	my $line = shift;
	chomp ($line);
	$line =~ s/data|=|detector//g;
	return $line;
}

##</code><code>##

xyzzy
data abc
detector = data
hooplah =
enddata

##</code><code>##

C:\>perl a.pl test.txt > out.txt

##</code><code>##

xyzzy abc  hooplah end