%listen() Function

The %listen() function marks the specified socket as accepting incoming connections and limits the number of outstanding connections in the system queue.

Syntax

code = %listen(fd, backlog)

Parameter(s)

fd	File descriptor of the local socket returned by a previous call to the FlashBASIC C function %socket().
backlog	Maximum number of outstanding connections. The maximum value for this number is SOMAXCONN defined in the include file: dm,bp,unix.h socket.h.

Description

To compile successfully, the statement cfunction socket.builtin must be included in the source code. Upon successful completion, a value of 0 is returned in code. In case of error, a value of -1 is returned and the system(0) function is set to the value of errno.

Example(s)

cfunction socket.builtin

include dm,bp,includes sysid.inc

include dm,bp,unix.h socket.h

* Create a socket

fd=%socket(af$inet, sock$stream, 0)

* Bind the socket to a local Ethernet port.

* Use default address.

char buffer[1024]

if %bind(fd, af$inet, inaddr$any, 1024)<0 then

crt ’bind failed’; stop

end

* Wait for incoming connection and allow up to

* three more to be waiting.

%listen(fd, 3)

* Accept a connection until got them all

loop

address=0; port=0

socket=%accept(fd, &address, &port)

until socket<0 do

crt ’Called by address ’:addr:’, port #’:port

* Read data from the data link

%recv(socket, buffer, 1024)

char buff[1024]

* Done with this connection, close it

%closesocket(socket)

repeat