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.Dd March 30, 2020 29.Dt BIND 2 30.Os 31.Sh NAME 32.Nm bind 33.Nd assign a local protocol address to a socket 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In sys/socket.h 38.Ft int 39.Fn bind "int s" "const struct sockaddr *addr" "socklen_t addrlen" 40.Sh DESCRIPTION 41The 42.Fn bind 43system call 44assigns the local protocol address to a socket. 45When a socket is created 46with 47.Xr socket 2 48it exists in an address family space but has no protocol address assigned. 49The 50.Fn bind 51system call requests that 52.Fa addr 53be assigned to the socket. 54.Sh NOTES 55Binding an address in the UNIX domain creates a socket in the file 56system that must be deleted by the caller when it is no longer 57needed (using 58.Xr unlink 2 ) . 59.Pp 60The rules used in address binding vary between communication domains. 61Consult the manual entries in section 4 for detailed information. 62.Pp 63For maximum portability, you should always zero the socket address structure 64before populating it and passing it to 65.Fn bind . 66.Sh RETURN VALUES 67.Rv -std bind 68.Sh ERRORS 69The 70.Fn bind 71system call will fail if: 72.Bl -tag -width Er 73.It Bq Er EAGAIN 74Kernel resources to complete the request are 75temporarily unavailable. 76.It Bq Er EBADF 77The 78.Fa s 79argument 80is not a valid descriptor. 81.It Bq Er EINVAL 82The socket is already bound to an address, and the protocol does not support 83binding to a new address; or the socket has been shut down. 84.It Bq Er EINVAL 85The 86.Fa addrlen 87argument is not a valid length for the address family. 88.It Bq Er ENOTSOCK 89The 90.Fa s 91argument 92is not a socket. 93.It Bq Er EADDRNOTAVAIL 94The specified address is not available from the local machine. 95.It Bq Er EADDRINUSE 96The specified address is already in use. 97.It Bq Er EAFNOSUPPORT 98Addresses in the specified address family cannot be used with this socket. 99.It Bq Er EACCES 100The requested address is protected, and the current user 101has inadequate permission to access it. 102.It Bq Er EFAULT 103The 104.Fa addr 105argument is not in a valid part of the user 106address space. 107.El 108.Pp 109The following errors are specific to binding addresses in the UNIX domain. 110.Bl -tag -width EADDRNOTAVA 111.It Bq Er ENOTDIR 112A component of the path prefix is not a directory. 113.It Bq Er ENAMETOOLONG 114A component of a pathname exceeded 255 characters, 115or an entire path name exceeded 1023 characters. 116.It Bq Er ENOENT 117A prefix component of the path name does not exist. 118.It Bq Er ELOOP 119Too many symbolic links were encountered in translating the pathname. 120.It Bq Er EIO 121An I/O error occurred while making the directory entry or allocating the inode. 122.It Bq Er EINTEGRITY 123Corrupted data was detected while reading from the file system. 124.It Bq Er EROFS 125The name would reside on a read-only file system. 126.It Bq Er EISDIR 127An empty pathname was specified. 128.El 129.Sh SEE ALSO 130.Xr connect 2 , 131.Xr getsockname 2 , 132.Xr listen 2 , 133.Xr socket 2 134.Sh HISTORY 135The 136.Fn bind 137system call appeared in 138.Bx 4.2 . 139