Question

I’m trying to use LISTSERV’s “API” in PHP. L-Soft calls this TCPGUI, and essentially, you can request data like over Telnet. To do this, I’m using PHP’s TCP socket functions.

Here’s the C code provided by L-Soft:

C: http://www.lsoft.com/manuals/16.0/htmlhelp/advanced%20topics/TCPGUI.html#2334328

I’ve provided the PHP conversion I’m using in my first answer. I hope this helps someone someday.

Answer 1

This is a one command at a time function a colleague wrote. Still wondering if more can be done in terms of flexibility, efficiency, and speed.

/*
 * lcmd - execute LISTSERV command
 *
 * This function connects to a LISTSERV host and executes a single command
 * using the supplied credentials.
 *
 * Returns result from command if successful; otherwise, returns FALSE.
 */
function lcmd($host, $port, $user, $password, $cmd) {
    $request_header = "";
    $request_body = "";
    $response_header = "";
    $response_body = "";
    $length = 0;
    $status;
    $result;

    /*
 * Get host address
 */
$host = gethostbyname($host);

/*
 * Connect to server
 */
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

if (!$socket) {
    return FALSE;
}

$status = socket_connect($socket, $host, $port);

if (!$status) {
    return FALSE;
}

/*
 * Format request body
 */
$request_body = "${cmd} PW=${password}";

$length = strlen($user) + strlen($request_body) + 1;

/*
 * Format request header
 */
$request_header = array();

$request_header[] = "1B\r\n";
$request_header[] = chr((int)($length / 256));
$request_header[] = chr($length % 255);
$request_header[] = chr(strlen($user));
$request_header[] = $user;

$request_header = implode($request_header);

/*
 * Send request header
 */
$status = socket_send(
    $socket,
    $request_header,
    strlen($request_header),
    0
);

if (strlen($request_header) != $status) {
    return FALSE;
}

/*
 * Receive response header
 */
while (socket_recv($socket, $b, 1, 0) == 1) {
    $response_header .= $b;
    if ("\n" == $b) {
        break;
    }
}

$status = (int)$response_header;

/*
 * If status is not 250, then the is refusing the request.
 */
if (250 != $status) {
    return FALSE;
}

/*
 * Send request body
 */
$status = socket_send(
    $socket,
    $request_body,
    strlen($request_body),
    0
);

if (strlen($request_body) != $status) {
    return FALSE;
}

/*
 * Receive response body
 *
 * The first 8 bytes of the body is two unsigned 32-bit integers
 * that define the status of the command and the length of the
 * result.
 */
$status = socket_recv($socket, $response_body, 8, 0);

if (8 != $status) {
    return FALSE;
}

/*
 * Decode unsigned 32-bit big-endian integer status and result
 * length.
 */
$response_body = str_split($response_body);

$status = (
    (ord($response_body[0]) << 24 ) |
    (ord($response_body[1]) << 16 ) |
    (ord($response_body[2]) <<  8 ) |
    (ord($response_body[3]) <<  0 )
);

$length = (
    (ord($response_body[4]) << 24 ) |
    (ord($response_body[5]) << 16 ) |
    (ord($response_body[6]) <<  8 ) |
    (ord($response_body[7]) <<  0 )
);

/*
 * If status is not 0, then command execution has failed.
 */
if (0 != $status) {
    return FALSE;
}

/*
 * Receive result
 */
$status = socket_recv($socket, $result, $length, MSG_WAITALL);

if ($length != $status) {
    return FALSE;
}

/*
 * Disconnect from server
 */
socket_close($socket);

/*
 * Return
 */
return $result;
}