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.\" 30.Dd March 30, 2020 31.Dt BIND 2 32.Os 33.Sh NAME 34.Nm bind 35.Nd assign a local protocol address to a socket 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In sys/socket.h 40.Ft int 41.Fn bind "int s" "const struct sockaddr *addr" "socklen_t addrlen" 42.Sh DESCRIPTION 43The 44.Fn bind 45system call 46assigns the local protocol address to a socket. 47When a socket is created 48with 49.Xr socket 2 50it exists in an address family space but has no protocol address assigned. 51The 52.Fn bind 53system call requests that 54.Fa addr 55be assigned to the socket. 56.Sh NOTES 57Binding an address in the UNIX domain creates a socket in the file 58system that must be deleted by the caller when it is no longer 59needed (using 60.Xr unlink 2 ) . 61.Pp 62The rules used in address binding vary between communication domains. 63Consult the manual entries in section 4 for detailed information. 64.Pp 65For maximum portability, you should always zero the socket address structure 66before populating it and passing it to 67.Fn bind . 68.Sh RETURN VALUES 69.Rv -std bind 70.Sh ERRORS 71The 72.Fn bind 73system call will fail if: 74.Bl -tag -width Er 75.It Bq Er EAGAIN 76Kernel resources to complete the request are 77temporarily unavailable. 78.It Bq Er EBADF 79The 80.Fa s 81argument 82is not a valid descriptor. 83.It Bq Er EINVAL 84The socket is already bound to an address, and the protocol does not support 85binding to a new address; or the socket has been shut down. 86.It Bq Er EINVAL 87The 88.Fa addrlen 89argument is not a valid length for the address family. 90.It Bq Er ENOTSOCK 91The 92.Fa s 93argument 94is not a socket. 95.It Bq Er EADDRNOTAVAIL 96The specified address is not available from the local machine. 97.It Bq Er EADDRINUSE 98The specified address is already in use. 99.It Bq Er EAFNOSUPPORT 100Addresses in the specified address family cannot be used with this socket. 101.It Bq Er EACCES 102The requested address is protected, and the current user 103has inadequate permission to access it. 104.It Bq Er EFAULT 105The 106.Fa addr 107argument is not in a valid part of the user 108address space. 109.El 110.Pp 111The following errors are specific to binding addresses in the UNIX domain. 112.Bl -tag -width EADDRNOTAVA 113.It Bq Er ENOTDIR 114A component of the path prefix is not a directory. 115.It Bq Er ENAMETOOLONG 116A component of a pathname exceeded 255 characters, 117or an entire path name exceeded 1023 characters. 118.It Bq Er ENOENT 119A prefix component of the path name does not exist. 120.It Bq Er ELOOP 121Too many symbolic links were encountered in translating the pathname. 122.It Bq Er EIO 123An I/O error occurred while making the directory entry or allocating the inode. 124.It Bq Er EINTEGRITY 125Corrupted data was detected while reading from the file system. 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