PHP - Verifying FTP connection - Detect FTP Timeout

Question

One of my CLI scripts downloads files via FTP.

The script opens an FTP connection, logs in, downloads the necessary files, and sleeps. Every so often it checks for the files again. This script is expected to run for days on end, as a daemon.

I want to be able to re-use an open connection (so I don't have to re-connect every loop).

$ftpconn = false;
$ftplogin = false;

while(1){

sleep(25);
if(!$ftpconn){
    $ftpconn = ftp_connect(HOST);
}
if(!$ftplogin){
    $ftplogin = ftp_login($ftpconn, USER, PASS);
}

// Do FTP stuff here

}

My question is this. Do both ftp_connect and ftp_login timeout? And if so, will $ftpconn and $ftplogin change to FALSE when that happens?

Thanks.

Answer 1

You're best bet on this is to implement your connection process. Then build your logic for trying to check for the file. (I'm assuming using something like ftp_nlist). ftp_nlist will return a FALSE if there is an error for any reason. At which point you can have your code close the existing connection using ftp_close (Which will give a FALSE if the connection was already closed for whatever reason) and then run the connection sequence again.

You'll want to build in logic that if the ftp_nlist fails more than a few times to exit out of your application. Unfortunately the various ftp_* commands don't have a lot of depth in regards to identifying why a function failed so you will have to build extra logic around it to compensate.