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Section: POSIX Programmer's Manual (3P)
Updated: 2013
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PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
bind
--- bind a name to a socket
SYNOPSIS
#include <sys/socket.h>
int bind(int socket, const struct sockaddr *address,
socklen_t address_len);
DESCRIPTION
The
bind()
function shall assign a local socket address
address
to a socket identified by descriptor
socket
that has no local socket address assigned. Sockets created with the
socket()
function are initially unnamed; they are identified only by their
address family.
The
bind()
function takes the following arguments:
- socket
-
Specifies the file descriptor of the socket to be bound.
- address
-
Points to a
sockaddr
structure containing the address to be bound to the socket. The length
and format of the address depend on the address family of the socket.
- address_len
-
Specifies the length of the
sockaddr
structure pointed to by the
address
argument.
The socket specified by
socket
may require the process to have appropriate privileges to use the
bind()
function.
If the address family of the socket is AF_UNIX and the pathname in
address
names a symbolic link,
bind()
shall fail and set
errno
to
[EADDRINUSE].
If the socket address cannot be assigned immediately and O_NONBLOCK is
set for the file descriptor for the socket,
bind()
shall fail and set
errno
to
[EINPROGRESS],
but the assignment request shall not be aborted, and the assignment
shall be completed asynchronously. Subsequent calls to
bind()
for the same socket, before the assignment is completed, shall fail
and set
errno
to
[EALREADY].
When the assignment has been performed asynchronously,
pselect(),
select(),
and
poll()
shall indicate that the file descriptor for the socket is ready for
reading and writing.
RETURN VALUE
Upon successful completion,
bind()
shall return 0; otherwise, -1 shall be returned and
errno
set to indicate the error.
ERRORS
The
bind()
function shall fail if:
- EADDRINUSE
-
The specified address is already in use.
- EADDRNOTAVAIL
-
The specified address is not available from the local machine.
- EAFNOSUPPORT
-
The specified address is not a valid address for the address family of
the specified socket.
- EALREADY
-
An assignment request is already in progress for the specified socket.
- EBADF
-
The
socket
argument is not a valid file descriptor.
- EINPROGRESS
-
O_NONBLOCK is set for the file descriptor for the socket and the
assignment cannot be immediately performed; the assignment shall be
performed asynchronously.
- EINVAL
-
The socket is already bound to an address, and the protocol does not
support binding to a new address; or the socket has been shut down.
- ENOBUFS
-
Insufficient resources were available to complete the call.
- ENOTSOCK
-
The
socket
argument does not refer to a socket.
- EOPNOTSUPP
-
The socket type of the specified socket does not support binding to an
address.
If the address family of the socket is AF_UNIX, then
bind()
shall fail if:
- EACCES
-
A component of the path prefix denies search permission, or the
requested name requires writing in a directory with a mode that denies
write permission.
- EDESTADDRREQ or EISDIR
-
The
address
argument is a null pointer.
- EIO
-
An I/O error occurred.
- ELOOP
-
A loop exists in symbolic links encountered during resolution of the
pathname in
address.
- ENAMETOOLONG
-
The length of a component of a pathname is longer than
{NAME_MAX}.
- ENOENT
-
A component of the path prefix of the pathname in
address
does not name an existing file or the pathname is an empty string.
- ENOENT or ENOTDIR
-
The pathname in
address
contains at least one non-<slash>
character and ends with one or more trailing
<slash>
characters. If the pathname names an existing file, an
[ENOENT]
error shall not occur.
- ENOTDIR
-
A component of the path prefix of the pathname in
address
names an existing file that is neither a directory nor a symbolic link
to a directory, or the pathname in
address
contains at least one non-<slash>
character and ends with one or more trailing
<slash>
characters and the last pathname component names an existing file
that is neither a directory nor a symbolic link to a directory.
- EROFS
-
The name would reside on a read-only file system.
The
bind()
function may fail if:
- EACCES
-
The specified address is protected and the current user does not have
permission to bind to it.
- EINVAL
-
The
address_len
argument is not a valid length for the address family.
- EISCONN
-
The socket is already connected.
- ELOOP
-
More than
{SYMLOOP_MAX}
symbolic links were encountered during resolution of the pathname in
address.
- ENAMETOOLONG
-
The length of a pathname exceeds
{PATH_MAX},
or pathname resolution of a symbolic link produced an intermediate
result with a length that exceeds
{PATH_MAX}.
The following sections are informative.
EXAMPLES
The following code segment shows how to create a socket and
bind it to a name in the AF_UNIX domain.
-
#define MY_SOCK_PATH "/somepath"
int sfd;
struct sockaddr_un my_addr;
sfd = socket(AF_UNIX, SOCK_STREAM, 0);
if (sfd == -1)
/* Handle error */;
memset(&my_addr, '\0', sizeof(struct sockaddr_un));
/* Clear structure */
my_addr.sun_family = AF_UNIX;
strncpy(my_addr.sun_path, MY_SOCK_PATH, sizeof(my_addr.sun_path) -1);
if (bind(sfd, (struct sockaddr *) &my_addr,
sizeof(struct sockaddr_un)) == -1)
/* Handle error */;
APPLICATION USAGE
An application program can retrieve the assigned socket name with the
getsockname()
function.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
connect(),
getsockname(),
listen(),
socket()
The Base Definitions volume of POSIX.1-2008,
<sys_socket.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.unix.org/online.html .
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
Index
- PROLOG
-
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- EXAMPLES
-
- APPLICATION USAGE
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-
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