NAME    [Toc]    [Back]

     listen - listen for connections on a socket

SYNOPSIS    [Toc]    [Back]

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

     int
     listen(int s, int backlog);

DESCRIPTION    [Toc]    [Back]

     To accept connections, a socket is first created with  socket(2), a willingness
 to accept incoming connections and a queue limit for
incoming
     connections are specified with listen(), and then  the  connections are accepted
  with  accept(2).   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 may receive an error with an  indication  of
ECONNREFUSED,
     or,  if the underlying protocol supports retransmission, the
request may
     be ignored so that retries may succeed.

RETURN VALUES    [Toc]    [Back]

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

ERRORS    [Toc]    [Back]

     listen() will fail 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().

SEE ALSO    [Toc]    [Back]

     accept(2), connect(2), socket(2)

HISTORY    [Toc]    [Back]

     The listen() function call appeared in 4.2BSD.

BUGS    [Toc]    [Back]

     The backlog is currently limited (silently) to 128.

OpenBSD      3.6                        December     11,     1993