1.\" Copyright (c) 1983, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)bind.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd June 26, 2014 32.Dt BIND 2 33.Os 34.Sh NAME 35.Nm bind 36.Nd assign a local protocol address to a socket 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In sys/types.h 41.In sys/socket.h 42.Ft int 43.Fn bind "int s" "const struct sockaddr *addr" "socklen_t addrlen" 44.Sh DESCRIPTION 45The 46.Fn bind 47system call 48assigns the local protocol address to a socket. 49When a socket is created 50with 51.Xr socket 2 52it exists in an address family space but has no protocol address assigned. 53The 54.Fn bind 55system call requests that 56.Fa addr 57be assigned to the socket. 58.Sh NOTES 59Binding an address in the UNIX domain creates a socket in the file 60system that must be deleted by the caller when it is no longer 61needed (using 62.Xr unlink 2 ) . 63.Pp 64The rules used in address binding vary between communication domains. 65Consult the manual entries in section 4 for detailed information. 66.Pp 67For maximum portability, you should always zero the socket address structure 68before populating it and passing it to 69.Fn bind . 70.Sh RETURN VALUES 71.Rv -std bind 72.Sh ERRORS 73The 74.Fn bind 75system call will fail if: 76.Bl -tag -width Er 77.It Bq Er EAGAIN 78Kernel resources to complete the request are 79temporarily unavailable. 80.It Bq Er EBADF 81The 82.Fa s 83argument 84is not a valid descriptor. 85.It Bq Er EINVAL 86The socket is already bound to an address, and the protocol does not support 87binding to a new address; or the socket has been shut down. 88.It Bq Er EINVAL 89The 90.Fa addrlen 91argument is not a valid length for the address family. 92.It Bq Er ENOTSOCK 93The 94.Fa s 95argument 96is not a socket. 97.It Bq Er EADDRNOTAVAIL 98The specified address is not available from the local machine. 99.It Bq Er EADDRINUSE 100The specified address is already in use. 101.It Bq Er EAFNOSUPPORT 102Addresses in the specified address family cannot be used with this socket. 103.It Bq Er EACCES 104The requested address is protected, and the current user 105has inadequate permission to access it. 106.It Bq Er EFAULT 107The 108.Fa addr 109argument is not in a valid part of the user 110address space. 111.El 112.Pp 113The following errors are specific to binding addresses in the UNIX domain. 114.Bl -tag -width EADDRNOTAVA 115.It Bq Er ENOTDIR 116A component of the path prefix is not a directory. 117.It Bq Er ENAMETOOLONG 118A component of a pathname exceeded 255 characters, 119or an entire path name exceeded 1023 characters. 120.It Bq Er ENOENT 121A prefix component of the path name does not exist. 122.It Bq Er ELOOP 123Too many symbolic links were encountered in translating the pathname. 124.It Bq Er EIO 125An I/O error occurred while making the directory entry or allocating the inode. 126.It Bq Er EROFS 127The name would reside on a read-only file system. 128.It Bq Er EISDIR 129An empty pathname was specified. 130.El 131.Sh SEE ALSO 132.Xr connect 2 , 133.Xr getsockname 2 , 134.Xr listen 2 , 135.Xr socket 2 136.Sh HISTORY 137The 138.Fn bind 139system call appeared in 140.Bx 4.2 . 141