If you want to make sure httpd is responding versus has a process running, try the following:

#!/usr/local/bin/perl -w

use strict;
use LWP::UserAgent;

my $debug = 0;
my $url = shift || die "Syntax is '$0 url-to-test': $!";

$debug && print "URL is $url\n";

my $ua = new LWP::UserAgent;
my $request = HTTP::Request->new('GET', "$url");
my $response = $ua->request($request);

if ($response->is_success) {
   exit 0;
} else {
   exit 1;
}
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I have been bitten in the past by checking for a process running.