Auto compile less on save in VIM on Mac OS X

.vimrc

" Call Function When Saving *.less files
autocmd FileWritePost,BufWritePost *.less :call HandleLessToCSS()
" Function to handle less compile
function! HandleLessToCSS()
	let cwd = expand('<afile>:p:h')
	let name = expand('<afile>:t:r')
	if(executable('less'))
		cal system('less '.cwd.'/'.name.'.less &')
	endif
endfunction

compile-less.php

#!/usr/bin/env php
<?php
//first arg should be full path to less file
$file = $argv[1];

if(!file_exists($file)) {
	echo "FILE DOES NOT EXISTS","\n";
	exit(1);
}

//some file info
$pi = pathinfo($file);

//grab the first line
$handle = fopen($file,"r");
$line = fgets($handle);
fclose($handle);

//check if the first line is a config
//line, if not then just compile to the
//same directory with the same name
if(!preg_match('/^\/\//',$line)) {
	$cmd = "less {$pi['dirname']}/{$pi['filename']}.css";
	passthru($cmd);
	exit(0);
}

//break apart the comma seperated lines
$line = str_replace("//","",$line);

//set some defaults
$redir = '';
$map_op = "";
$comp_op = "";
$opts = explode(",",$line);

foreach($opts as $opt) {

	$o = explode(":",$opt);

	if(!isset($o[1])) {
		continue;
	}
	foreach($o as $k=>$v) {

		$o[$k] = trim($v);
	}
	//output path
	if(strtolower($o[0]) == "out") {
		$realpath = dirname( realpath($file))."/";
		$outputPath = "{$realpath}{$o[1]}";
		$destPath = dirname($outputPath);

		if(!is_dir($destPath)) {
			mkdir($destPath,0777,true);
		}
		$redir =  " {$outputPath}";
	}

	//build map
	if(strtolower($o[0]) == "map") {
		if(filter_var($o[1],FILTER_VALIDATE_BOOLEAN)) {
			$map_op = "--source-map";
		}
	}

	//compress
	if(strtolower($o[0]) == "compress") {
		if(filter_var($o[1],FILTER_VALIDATE_BOOLEAN)) {
			$comp_op = " -x ";
		}
	}


}

if(empty($redir)) {
	exit(1);
}

$cmd = "lessc {$comp_op} -s {$map_op}  {$file} {$redir} ";

passthru($cmd);
//done

install-npm-less.sh

#install nodejs NPM Package Manager
## Using Macports
sudo port install npm;

#Once you have NPM Package Manager installed, install the less package
sudo npm install less --global

# Dump the less version to ensure you're shell session
# has the correct path to less
less --version

# should output something similar to
# OUT: less 458 ........