NAME

listen − listen for connections on a socket

SYNOPSIS

cc [ flag ... ] file ... −lsocket −lnsl [ library ... ]

#include <sys/types.h>
#include <sys/socket.h>

int listen(int s, int backlog);

MT-LEVEL

Safe

DESCRIPTION

To accept connections, a socket is first created with socket(3N), a backlog for incoming connections is specified with listen() and then the connections are accepted with accept(3N).  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

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(3N), connect(3N), socket(3N)

NOTES

There is currently no backlog limit. 

Sun Microsystems  —  Last change: 30 Mar 1993