如何使用PHP编写带有条件的文本文件

I have a problem in my code. My code is all about updating/deleting rows in textfile ig the textfile is found. I am having a trouble with it. At first I can add a new textfile and together with it I can also update this file. But it is for 1 row. If I update another row. It will just append the updated value at the end of the textfile. What I want is to update this or delete and insert the new one. But I don't know how. My process in updating the array is array_replace(). First I need to find out if the ID of my data is found in the textfile. If found I will simple update/delete and replace the existing data into my new updated data. If not found just add only.

Here's my code for that.

        $restaurant_id = $post_data['company_id']; 
        $new_lat_entry = $post_data['new_lat']; 
        $new_long_entry = $post_data['new_long']; 

        /****Here's my new updated array ****/
        $data_add = array( 
            'restaurant_id' => $restaurant_id, 
            'new_lat' => $new_lat_entry, 
            'new_long' => $new_long_entry, 
            'date_updated' => date('Y-m-d H:i:s') 
        ); 
        /****This is the BASE array from the existing textfile ****/
        $data = unserialize(file_get_contents('addresses.txt'));

        $target = $data_add['restaurant_id'];

        for ($i = 0; $i < count($data); $i++) {

            $get_id = $data[$i]['restaurant_id'];

            if($get_id == $target){

                //If ID is found - UPDATE

                $add_data = array();

                $add_data = array(
                    $i => $data_add
                );

                $new_array = array();
                $new_array = array_replace($data,$add_data);

                $serialize_data = serialize($new_array); 
                                $file_input_txt = fopen("addresses.txt","w+"); 
            fwrite($file_input_txt,$serialize_data); 
            fclose($file_input_txt); 

            }else{

                $new_array = array(
                    $i => $data_add
                );

                $serialize_data = serialize($new_array); 

                $file_input_txt = fopen("addresses.txt","w+"); 
                                fwrite($file_input_txt,$serialize_data); 
                fclose($file_input_txt); 


            }

    }

The output of my text file is in serialized form.

a:1:{i:0;a:4:{s:13:"restaurant_id";s:4:"1519";s:7:"new_lat";s:8:"14.63823";s:8:"new_long";s:9:"121.02999";s:12:"date_updated";s:19:"2013-11-15 12:42:59";}}

That's all guys please help me. I have a deadline now. And I am stuck with it. :-( This is the first time I am creating a CRUD based on a text file that's why I am having a trouble debugging it.

Can you please try this,

        <?php   

        /****This is the BASE array from the existing textfile ****/
        $data = unserialize(file_get_contents('addresses.txt'));

        $restaurant_id = '1519';
        $new_lat_entry = '14.64823';
        $new_long_entry = '121.45999';

        /****Here's my new updated array ****/
        $data_add = array(
                'restaurant_id' => $restaurant_id,
                'new_lat' => $new_lat_entry,
                'new_long' => $new_long_entry,
                'date_updated' => date('Y-m-d H:i:s')
        );

        $target = $data_add['restaurant_id'];

        $Count =count($data);
        $new_array =array();
        for ($i = 0; $i < $Count; $i++) {

             $get_id = $data[$i]['restaurant_id'];


                //If ID is found - UPDATE   

                $add_data = array(
                        $i => $data_add
                );

                if($get_id == $target){
                    $new_array = array_replace($data,$add_data);    
                }

        }
        $serialize_data= serialize($new_array);

        print_r($serialize_data);
        $file_input_txt = fopen("addresses.txt","w+");
        fwrite($file_input_txt, $serialize_data);
        fclose($file_input_txt);


    ?>