HTTPClose

Command group Flag affected Reversible Execute on client Platform(s)
External commands YES NO NO All

Syntax

HTTPClose (socket[,option {Default zero for complete;1 for partial;2 for abort}]) Returns status

Description

Note: The flag is set according to whether Omnis was able to make a call to this external command.

This Web command is multi-threaded,allowing another thread to execute in the multi-threaded server while it runs. Note that the same socket cannot safely be used concurrently by more than one thread.

HTTPClose closes, and depending on the Option, releases a Socket. When the socket is connected, this will result in the closure of the connection to the remote application. All new sockets returned by all Web commands, must eventually be released using HTTPClose, to avoid resource leakage.

The most brutal form of HTTPClose is an abortive close. In this case, no consideration is given to the state of the connection, or exchanges with the remote application, and the socket is closed and released immediately. This form of HTTPClose is recommended for use in error handling situations.

The mildest form of HTTPClose is a partial close. In this case, the socket is not released, and you will need to call HTTPClose again to release the socket. A partial close initiates a disconnect of the TCP/IP connection, by sending a TCP/IP packet with the finish flag set. This means that you can no longer send data to the remote application, but you can continue to receive data. The remote application will be informed of the partial close, when it receives zero bytes.

The remaining form of HTTPClose is a complete close. In this form, HTTPClose initiates a close of the connection if necessary, receives data on the connection until no more is available (to flush the connection), and releases the socket.

Socket is an Omnis Long Integer field containing a number representing a previously opened socket.

Option is an optional Omnis Integer field, which has the value zero for a complete close, 1 for a partial close, and 2 for an abortive close. If omitted, it defaults to a complete close.

Status is an Omnis Long Integer field which receives the value zero for success, or an error code < 0 for failure. Possible error codes are listed in the Web Command Error Codes Appendix.

Example

; Connect to the server IP address iHostName on port iPort, send
; the message iMessage and then close the socket
Calculate iHostName as '0.0.0.0'
Calculate iPort as 6000
Calculate lMessage as 'Hello remote application'
HTTPOpen (iHostName,iPort) Returns iSocket
If iSocket>0
  ; connected
  HTTPSend (iSocket,lMessage) Returns lCharCount
End If
HTTPClose (iSocket)