listen(2)
NAME
listen − listen for connections on a socket
SYNTAX
listen(s, backlog)
int s, backlog;
DESCRIPTION
To accept connections, a socket is first created with socket(,), a backlog for incoming connections is specified with listen() and then the connections are accepted with accept(.). The listen call applies only to sockets of type SOCK_STREAM or SOCK_SEQPACKET.
The backlog parameter defines the maximum length the queue of pending connections may grow to. If a connection request arrives with the queue full the client will receive an error with an indication of ECONNREFUSED.
RESTRICTIONS
The backlog is currently limited to 5.
RETURN VALUE
A 0 return value indicates success. A −1 indicates an error.
DIAGNOSTICS
The call fails if:
[EBADF] The argument s is not a valid descriptor.
[ENOTSOCK] The argument s is not a socket.
[EOPNOTSUPP] The socket is not of a type that supports the operation listen.