Why does php use curl to upload files and it cannot be executed after deleting a sentence?

<code>   <?php
   function upload_file($url,$filename,$path){
        $data = array('pic'=>'@'.realpath($path).";filename=".$filename);
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true );
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $return_data = curl_exec($ch);
        curl_close($ch);
        $decode = json_decode($return_data);
        echo $decode->original_pic;      
   }

    if ($_POST) {
        $url = 'https://127.0.0.1/img.php';
        $tmpname = $_FILES['fname']['name'];
        $tmpfile = $_FILES['fname']['tmp_name'];
        upload_file($url,$tmpname,$tmpfile);
        exit;
    }
    echo '<form action="" enctype="multipart/form-data"  method="post">
    <input type="text" name="fname" />
  <input type="file" name="fname" />
  <input type="submit" value="Submit" />
</form>';
?>
</code>

The code is as above, why can’t I post after deleting ?

Reply content:

<code>   <?php
   function upload_file($url,$filename,$path){
        $data = array('pic'=>'@'.realpath($path).";filename=".$filename);
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true );
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $return_data = curl_exec($ch);
        curl_close($ch);
        $decode = json_decode($return_data);
        echo $decode->original_pic;      
   }

    if ($_POST) {
        $url = 'https://127.0.0.1/img.php';
        $tmpname = $_FILES['fname']['name'];
        $tmpfile = $_FILES['fname']['tmp_name'];
        upload_file($url,$tmpname,$tmpfile);
        exit;
    }
    echo '<form action="" enctype="multipart/form-data"  method="post">
    <input type="text" name="fname" />
  <input type="file" name="fname" />
  <input type="submit" value="Submit" />
</form>';
?>
</code>

The code is as above, why can’t I post after deleting ?

Is there any error message? Post it and take a look

. . . There should be an error. Does the execution return nothing? Then we can only interrupt and see which step causes the problem

The uploaded file information should be stored in $_FILES and not in $_POST. Then there will be nothing in your post. Type $_POST in advance.

I didn’t find the document description. I just tried it and set one for submit. name