basic.%listen
Listens for incoming connections and limits the backlog of incoming connections.
Syntax
code=%listen( socket, backlog )
Description
marks the specified socket as accepting incoming connections and limits the number of outstanding connections in the system queue.
To compile successfully, the statement 'cfunction socket.builtin' must be included in the source code.
'socket' Is the file descriptor of the local socket returned by a previous call to the Pick/BASIC C function '%socket'.
'backlog' Maximum number of outstanding connections. The maximum value for this number is SOMAXCONN defined in the include: 'dm,bp,unix.h socket.h'
Upon successful completion, a value of 0 is returned in 'code'. In case of error, a value of -1 is returned and the function 'SYSTEM(0)' is set to the value of 'errno'.
Example
cfunction socket.builtin
include dm,bp,unix.h socket.h
* Create a socket
fd=%socket( AF$INET, SOCKET$STREAM, 0 )
* Bind the socket to a local Ethernet port.
* Use default address.
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
addr=0; port=0
fd=%accept( socket, &addr, &port )
until fd<0 do
crt 'Called by address ':addr:', port #':port
* Read data from the data link
%read( fd, buffer, 1024 )
* Done with this connection, close it
%close( fd )
repeat
See Also
User Comments
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