Miscellaneous PHP Functions

command_exists.inc.php

<?php
function command_exists($cmd) {
	return shell_exec('command -v '.$cmd.' >/dev/null && echo 1 || echo 0');
}

file_get_head.inc.php

<?php
// Tries to get only the URL's HEAD contents and not the body.
function file_get_head($url) {

	$ch = curl_init();
	$max_redirects = 5;
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $max_redirects > 0);
	curl_setopt($ch, CURLOPT_MAXREDIRS, $max_redirects);
	curl_setopt($ch, CURLOPT_HEADER, true); // TRUE to include the header in the output.
	curl_setopt($ch, CURLOPT_NOBODY, true); // TRUE to exclude the body from the output. Request method is then set to HEAD. Changing this to FALSE does not change it to GET.
	curl_setopt($ch, CURLOPT_FORBID_REUSE, true); // TRUE to force the connection to explicitly close when it has finished processing, and not be pooled for reuse.
	curl_setopt($ch, CURLOPT_FRESH_CONNECT, true); // TRUE to force the use of a new connection instead of a cached one
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // TRUE to return the transfer as a string of the return value of curl_exec() instead of outputting it out directly.
	curl_setopt($ch, CURLOPT_URL, $url);

	$header = curl_exec($ch);

	if (curl_errno($ch)) { 
		$code = 0; 
	}
	else { 
		$code = curl_getinfo($ch, CURLINFO_HTTP_CODE); 
	}

	return array('code' => $code, 'header' => $header);

}

mempty.inc.php

<?php
// Taken from http://stackoverflow.com/a/7798842
function mempty() {
	foreach (func_get_args() as $arg) {
		if (empty($arg)) {
			continue;
		}
		else {
			return false;
		}
		return true;
	}
}