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.\" 3. 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 March 30, 2020 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/socket.h 41.Ft int 42.Fn bind "int s" "const struct sockaddr *addr" "socklen_t addrlen" 43.Sh DESCRIPTION 44The 45.Fn bind 46system call 47assigns the local protocol address to a socket. 48When a socket is created 49with 50.Xr socket 2 51it exists in an address family space but has no protocol address assigned. 52The 53.Fn bind 54system call requests that 55.Fa addr 56be assigned to the socket. 57.Sh NOTES 58Binding an address in the UNIX domain creates a socket in the file 59system that must be deleted by the caller when it is no longer 60needed (using 61.Xr unlink 2 ) . 62.Pp 63The rules used in address binding vary between communication domains. 64Consult the manual entries in section 4 for detailed information. 65.Pp 66For maximum portability, you should always zero the socket address structure 67before populating it and passing it to 68.Fn bind . 69.Sh RETURN VALUES 70.Rv -std bind 71.Sh ERRORS 72The 73.Fn bind 74system call will fail if: 75.Bl -tag -width Er 76.It Bq Er EAGAIN 77Kernel resources to complete the request are 78temporarily unavailable. 79.It Bq Er EBADF 80The 81.Fa s 82argument 83is not a valid descriptor. 84.It Bq Er EINVAL 85The socket is already bound to an address, and the protocol does not support 86binding to a new address; or the socket has been shut down. 87.It Bq Er EINVAL 88The 89.Fa addrlen 90argument is not a valid length for the address family. 91.It Bq Er ENOTSOCK 92The 93.Fa s 94argument 95is not a socket. 96.It Bq Er EADDRNOTAVAIL 97The specified address is not available from the local machine. 98.It Bq Er EADDRINUSE 99The specified address is already in use. 100.It Bq Er EAFNOSUPPORT 101Addresses in the specified address family cannot be used with this socket. 102.It Bq Er EACCES 103The requested address is protected, and the current user 104has inadequate permission to access it. 105.It Bq Er EFAULT 106The 107.Fa addr 108argument is not in a valid part of the user 109address space. 110.El 111.Pp 112The following errors are specific to binding addresses in the UNIX domain. 113.Bl -tag -width EADDRNOTAVA 114.It Bq Er ENOTDIR 115A component of the path prefix is not a directory. 116.It Bq Er ENAMETOOLONG 117A component of a pathname exceeded 255 characters, 118or an entire path name exceeded 1023 characters. 119.It Bq Er ENOENT 120A prefix component of the path name does not exist. 121.It Bq Er ELOOP 122Too many symbolic links were encountered in translating the pathname. 123.It Bq Er EIO 124An I/O error occurred while making the directory entry or allocating the inode. 125.It Bq Er EINTEGRITY 126Corrupted data was detected while reading from the file system. 127.It Bq Er EROFS 128The name would reside on a read-only file system. 129.It Bq Er EISDIR 130An empty pathname was specified. 131.El 132.Sh SEE ALSO 133.Xr connect 2 , 134.Xr getsockname 2 , 135.Xr listen 2 , 136.Xr socket 2 137.Sh HISTORY 138The 139.Fn bind 140system call appeared in 141.Bx 4.2 . 142