fantastic secure random bytes from native PHP

Random.php

<?php

namespace lewiscowles\security {
	Class Random {

		const SECRANDSRC = '/dev/urandom';
		const DEFAULT_RANDOM_BYTES = 16;

		public static function getTrueRandomBytes( $cnt=16 ) {
			$out = '';
			$cnt = intval( $cnt ) > 0 ? intval( $cnt) : self::DEFAULT_RANDOM_BYTES;
			if( file_exists( self::SECRANDSRC ) && is_readable( self::SECRANDSRC ) ) {
				$fp = fopen( self::SECRANDSRC, 'r' );
				$out = fread( $fp, $cnt );
				fclose( $fp );
			} else {
				throw new Exception('Don\'t Run a *nix system, don\'t use my code');
			}
			return $out;
		}
	}

}