PHP determines the request type, which can be achieved through the parameters related to $_SERVER.

This is very common in the reuse of some request code. The specific code is as follows:

/**
* @todo : determine whether it is a post
*/  
if(!function_exists('is_post')){
	function  is_post ()
	{
	   return isset($_SERVER['REQUEST_METHOD']) && strtoupper($_SERVER['REQUEST_METHOD'])=='POST';	
	}
}
 
/**
* @todo : determine whether it is get
*/ 
if(!function_exists('is_get')){
	function is_get()
	{
	   return isset($_SERVER['REQUEST_METHOD']) && strtoupper($_SERVER['REQUEST_METHOD'])=='GET'; 	
	}
}
 
/**
* @todo : determine whether it is ajax
*/ 
if(!function_exists('is_ajax')){
	function is_ajax()
	{
	    return isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtoupper($_SERVER['HTTP_X_REQUESTED_WITH'])=='XMLHTTPREQUEST';	
	}
}
 
/**
* @todo : determine whether it is in command line mode
*/ 
if(!function_exists('is_cli')){
	function  is_cli ()
	{
            return (PHP_SAPI === 'cli' OR defined('STDIN'));  
	}
}