Write an array to a file in php and then read it

I have seen many open source projects before. The configuration information of some projects is generally written in files.
Some are written to constants in configuration files, and some are written to arrays.

However, those that are relatively complex and arrays have not been studied in depth. I took a rough look at the constants.
Generally, when modifying, it is more complicated. First, you need to read out all the configuration files,
Then replace the content through regular matching, and then write it into the file.

The one I used below This method is relatively simple and easy, I will post the code

Php code

if(isset($_POST['sub'])){                 
    $cfg = array('contact'=>$_POST['contact']);  //把数据存入数组             
    file_put_contents('./data/contact.cache',serialize($cfg));  
        //把数组序列化之后，写到contact.cache里，  
    $this->redirect('other/contact');//跳转  
 }  
 else{                
    $fp = fopen('./data/contact.cache','r');//读  
    $cf = unserialize(fread($fp,filesize('./data/contact.cache')));//反序列化，并赋值  
    $this->assign('cfg',$cf);//送到前台模板  
    $this->display('other/contact');  
 }