.\"	$NetBSD: getsockname.2,v 1.6 1995/10/12 15:41:00 jtc Exp $
.\"
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.\"     @(#)getsockname.2	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt GETSOCKNAME 2
.Os BSD 4.2
.Sh NAME
.Nm getsockname
.Nd get socket name
.Sh SYNOPSIS
.Fd #include <sys/socket.h>
.Ft int
.Fo getsockname
.Fa "int socket"
.Fa "struct sockaddr *restrict address"
.Fa "socklen_t *restrict address_len"
.Fc
.Sh DESCRIPTION
The
.Fn getsockname
function returns the current
.Fa address
for the specified socket. 
.Pp
The
.Fa address_len
parameter should be initialized to indicate
the amount of space pointed to by
.Fa address .
On return it contains the actual size of the address
returned (in bytes).
.Pp
The address is truncated if the buffer provided is too small.
.Pp
Note: For the UNIX domain, the address length returned is the
.Fa address_len
parameter passed to the previous
.Xr bind 2
system call and not the
.Va sa_len
field of the
.Fa address
parameter passed to
.Xr bind 2 .
.Sh RETURN VALUES
.Rv -std getsockname
.Sh ERRORS
The
.Fn getsockname
system call will succeed unless:
.Bl -tag -width Er
.\" ==========
.It Bq Er EBADF
The argument
.Fa socket
is not a valid file descriptor.
.\" ==========
.It Bq Er EFAULT
The 
.Fa address
parameter points to memory not in a valid part of the
process address space.
.\" ==========
.It Bq Er EINVAL
.Fa socket
has been shut down.
.\" ==========
.It Bq Er ENOBUFS
Insufficient resources were available in the system
to perform the operation.
.\" ==========
.It Bq Er ENOTSOCK
The argument
.Fa socket
is not a socket (e.g., a plain file).
.\" ==========
.It Bq Er EOPNOTSUPP
.Fn getsockname
is not supported for the protocol in use by
.Fa socket .
.El
.Sh SEE ALSO
.Xr bind 2 ,
.Xr socket 2
.Sh BUGS
Names bound to sockets in the UNIX domain are inaccessible;
.Fn getsockname
returns a zero-length address.
.Sh HISTORY
The
.Fn getsockname
call appeared in
.Bx 4.2 .