NAME

listen – listen for connections on a socket

SYNOPSIS

#include <sys/socket.h>

int listen(int s , int 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.

RETURN VALUES

A 0 return value indicates success; -1 indicates an error.

ERRORS

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:

EBADF

The argument s is not a valid file descriptor.

ENOTSOCK

The argument s is not a socket.

EOPNOTSUPP

The socket is not of a type that supports the operation listen().

SEE ALSO

accept(), connect(), socket()

NOTES

There is currently no backlog limit.