listen - listen for connections on a socket
#include <sys/socket.h>
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.
A 0 return value indicates success; -1 indicates an error.
This function is a member of Unison's IOLIB family of functions. IOLIB is implemented as a message passing and generalized interface layer. Each Unison I/O server is responsible for its own error reporting.
For an exact list of error codes returned by a particular server, refer to that server's documentation in the Unison Programmer's Guide for each specific platform.
Servers may implement these errors codes in response to this function.
The call fails if:
There is currently no backlog limit.