LISTEN(3SOCKET)LISTEN(3SOCKET)NAMElisten - 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);
DESCRIPTION
To accept connections, a socket is first created with socket(3SOCKET),
a backlog for incoming connections is specified with listen() and then
the connections are accepted with accept(3SOCKET). 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 for AF_UNIX sock‐
ets. If the underlying protocol supports retransmission, the connec‐
tion request may be ignored so that retries may succeed. For AF_INET
and AF_INET6sockets, the TCP will retry the connection. If the backlog
is not cleared by the time the tcp times out, the connect will fail
with ETIMEDOUT.
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().
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│MT-Level │ Safe │
└───────────────┴─────────────────┘
SEE ALSOaccept(3SOCKET), connect(3SOCKET), socket(3SOCKET), attributes(5),
socket.h(3HEAD)NOTES
There is currently no backlog limit.
Nov 8, 1999 LISTEN(3SOCKET)
