.\"	$OpenBSD: bind.2,v 1.15 2007/05/31 19:19:32 jmc Exp $
.\"	$NetBSD: bind.2,v 1.8 1995/10/12 15:40:46 jtc Exp $
.\"
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.\"     @(#)bind.2	8.1 (Berkeley) 6/4/93
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt BIND 2
.Os
.Sh NAME
.Nm bind
.Nd bind a name to a socket
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/socket.h>
.Ft int
.Fn bind "int s" "const struct sockaddr *name" "socklen_t namelen"
.Sh DESCRIPTION
.Fn bind
assigns a name to an unnamed socket.
When a socket is created with
.Xr socket 2
it exists in a name space (address family) but has no name assigned.
.Fn bind
requests that
.Fa name
be assigned to the socket.
.Fa namelen
indicates the amount of space pointed to by
.Fa name ,
in bytes.
.Sh NOTES
Binding a name in the UNIX domain creates a socket in the file
system that must be deleted by the caller when it is no longer
needed (using
.Xr unlink 2 ) .
.Pp
The rules used in name binding vary between communication domains.
Consult the manual entries in section 4 for detailed information.
.Sh RETURN VALUES
If the bind is successful, a 0 value is returned.
A return value of \-1 indicates an error, which is
further specified in the global
.Va errno .
.Sh ERRORS
The
.Fn bind
call will fail if:
.Bl -tag -width Er
.It Bq Er EBADF
.Fa s
is not a valid descriptor.
.It Bq Er ENOTSOCK
.Fa s
is not a socket.
.It Bq Er EADDRNOTAVAIL
The specified address is not available from the local machine.
.It Bq Er EADDRINUSE
The specified address is already in use.
.It Bq Er EINVAL
The socket is already bound to an address.
.It Bq Er EINVAL
The family of the socket and that requested in
.Va name->sa_family
are not equivalent.
.It Bq Er EACCES
The requested address is protected, and the current user
has inadequate permission to access it.
.It Bq Er EFAULT
The
.Fa name
parameter is not in a valid part of the user address space.
.El
.Pp
The following errors are specific to binding names in the UNIX domain.
.Bl -tag -width Er
.It Bq Er ENOTDIR
A component of the path prefix is not a directory.
.It Bq Er ENAMETOOLONG
A component of a pathname exceeded
.Dv {NAME_MAX}
characters, or an entire path name exceeded
.Dv {PATH_MAX}
characters.
.It Bq Er ENOENT
A prefix component of the path name does not exist.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
.It Bq Er EIO
An I/O error occurred while making the directory entry or allocating the inode.
.It Bq Er EROFS
The name would reside on a read-only file system.
.It Bq Er EISDIR
An empty pathname was specified.
.El
.Sh SEE ALSO
.Xr connect 2 ,
.Xr getsockname 2 ,
.Xr listen 2 ,
.Xr socket 2
.Sh HISTORY
The
.Fn bind
function call appeared in
.Bx 4.2 .