#!/usr/bin/perl

$| = 1;  # Make sure the header gets sent first.

print "Content-type: text/html\n\n";
exec "... 2>&1";

# We only get here if exec failed.
my $error = "Error executing nmap: $!";
$error =~ s/&/&/g;
$error =~ s/</&lt;/g;
print("$error\n");