_CONNECTED - mkilgore/QB64pe GitHub Wiki

The _CONNECTED function returns the status of a TCP/IP connection handle.

Syntax

result& = _CONNECTED(connectionHandle&)

The handle can come from the _OPENHOST, OPENCLIENT or _OPENCONNECTION QB64 TCP/IP functions.
Returns -1 if still connected or 0 if connection has ended/failed.
Do not rely solely on this function to check for ending communication.
Use "time-out" checking as well and CLOSE any suspect connections.
If this function indicates the handle is not connected, any unread messages can still be read using GET #.
Even if this function indicates the handle is not connected, it is important to CLOSE the connection anyway or important resources cannot be reallocated.