LISTEN(2,L)                 AIX Technical Reference                 LISTEN(2,L)



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listen



PURPOSE

Listens for connections on a socket.

LIBRARY

Internet Library (libc.a)

SYNTAX

int listen (s, backlog)
int s, backlog;

DESCRIPTION

To accept connections, create a socket with socket, specify a backlog for
incoming connections with listen, and accept the connections with accept.  The
listen system call applies only to sockets of type SOCK_STREAM.

The backlog parameter defines the maximum length for the queue of pending
connections.  The maximum value of the backlog parameter is 5.  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

Upon successful completion, a value of 0 is returned.  If the listen system
call fails, a value of -1 is returned, and errno is set to indicate the error.

ERROR CONDITIONS

The system call fails if one or more of the following are true:

EBADF        The s parameter is not valid.

ENOTSOCK     The s parameter refers to a file, not a socket.

EOPNOTSUPP   The referenced socket is not of type that supports listen.

EINVAL       The referenced socket refers to a NULL inode.

RELATED INFORMATION

In this book:  "accept," "connect," and "socket."





Processed November 7, 1990        LISTEN(2,L)                                 1