Visual FoxPro

Check the IMAP Socket Connection

Demonstrates the Chilkat Imap.CheckConnection method, which checks whether the underlying TCP socket is currently connected to the IMAP server. This performs a low-level socket-state check and does not send an IMAP command. This example connects and checks the socket.

Background: CheckConnection sits between the cached IsConnected and a full protocol round trip: it inspects the actual socket without sending an IMAP command, so it can catch a locally-closed socket that the cached flag would miss. It still cannot detect every half-open connection, though — only a real command like Noop that expects a server reply proves the session is genuinely alive end to end.

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LOCAL lnSuccess
LOCAL loImap
LOCAL lnStillConnected

lnSuccess = 0

*  Demonstrates the Imap.CheckConnection method, which checks whether the underlying TCP
*  socket is currently connected to the IMAP server.  This is a low-level socket-state check
*  and does not send an IMAP command.

loImap = CreateObject('Chilkat.Imap')

loImap.Ssl = 1
loImap.Port = 993

lnSuccess = loImap.Connect("imap.example.com")
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

*  Perform a low-level check of the socket connection state.
lnStillConnected = loImap.CheckConnection()
IF (lnStillConnected = 1) THEN
    ? "The socket is still connected."
ELSE
    ? "The socket is no longer connected."
ENDIF

lnSuccess = loImap.Disconnect()
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

RELEASE loImap