Title: POP3::send_cmd
Published: February 3, 2022
Last modified: May 20, 2026

---

# POP3::send_cmd( $cmd = "" )

## In this article

 * [Source](https://developer.wordpress.org/reference/classes/pop3/send_cmd/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/pop3/send_cmd/?output_format=md#related)

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## 󠀁[Source](https://developer.wordpress.org/reference/classes/pop3/send_cmd/?output_format=md#source)󠁿

    ```php
    function send_cmd ( $cmd = "" )
    {
        //  Sends a user defined command string to the
        //  POP server and returns the results. Useful for
        //  non-compliant or custom POP servers.
        //  Do NOT include the \r\n as part of your command
        //  string - it will be appended automatically.

        //  The return value is a standard fgets() call, which
        //  will read up to $this->BUFFER bytes of data, until it
        //  encounters a new line, or EOF, whichever happens first.

        //  This method works best if $cmd responds with only
        //  one line of data.

        if(!isset($this->FP))
        {
            $this->ERROR = "POP3 send_cmd: " . _("No connection to server");
            return false;
        }

        if(empty($cmd))
        {
            $this->ERROR = "POP3 send_cmd: " . _("Empty command string");
            return "";
        }

        $fp = $this->FP;
        $buffer = $this->BUFFER;
        $this->update_timer();
        fwrite($fp,"$cmd\r\n");
        $reply = fgets($fp,$buffer);
        $reply = $this->strip_clf($reply);
        if($this->DEBUG) { @error_log("POP3 SEND [$cmd] GOT [$reply]",0); }
        return $reply;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-pop3.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-includes/class-pop3.php#L447)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-includes/class-pop3.php#L447-L482)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/pop3/send_cmd/?output_format=md#related)󠁿

| Uses | Description | 
| [POP3::strip_clf()](https://developer.wordpress.org/reference/classes/pop3/strip_clf/)`wp-includes/class-pop3.php` |  | 
| [POP3::update_timer()](https://developer.wordpress.org/reference/classes/pop3/update_timer/)`wp-includes/class-pop3.php` |  |

| Used by | Description | 
| [POP3::user()](https://developer.wordpress.org/reference/classes/pop3/user/)`wp-includes/class-pop3.php` |  | 
| [POP3::pass()](https://developer.wordpress.org/reference/classes/pop3/pass/)`wp-includes/class-pop3.php` |  | 
| [POP3::apop()](https://developer.wordpress.org/reference/classes/pop3/apop/)`wp-includes/class-pop3.php` |  | 
| [POP3::pop_list()](https://developer.wordpress.org/reference/classes/pop3/pop_list/)`wp-includes/class-pop3.php` |  | 
| [POP3::get()](https://developer.wordpress.org/reference/classes/pop3/get/)`wp-includes/class-pop3.php` |  | 
| [POP3::last()](https://developer.wordpress.org/reference/classes/pop3/last/)`wp-includes/class-pop3.php` |  | 
| [POP3::reset()](https://developer.wordpress.org/reference/classes/pop3/reset/)`wp-includes/class-pop3.php` |  | 
| [POP3::uidl()](https://developer.wordpress.org/reference/classes/pop3/uidl/)`wp-includes/class-pop3.php` |  | 
| [POP3::delete()](https://developer.wordpress.org/reference/classes/pop3/delete/)`wp-includes/class-pop3.php` |  |

[Show 4 more](https://developer.wordpress.org/reference/classes/pop3/send_cmd/?output_format=md#)
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