LISTEN
Section: Linux Programmer's Manual (2)
Updated: 23 July 1993
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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(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 VALUE
On success, zero is returned. On error, -1 is returned, and
errno
is set appropriately.
ERRORS
- 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.
HISTORY
The
listen
function call appeared in BSD 4.2.
BUGS
If the socket is of type af_inet, and the backlog argument is greater
than 128 it is silently truncated to 128. For portable applications
don't rely on this value since BSD (and at least some BSD derived systems)
limit the backlog to 5.
SEE ALSO
accept(2), connect(2), socket(2)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- HISTORY
-
- BUGS
-
- SEE ALSO
-
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