PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

BIND(3P)                  POSIX Programmer's Manual                 BIND(3P)

PROLOG         top

       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         top

       bind — bind a name to a socket

SYNOPSIS         top

       #include <sys/socket.h>

       int bind(int socket, const struct sockaddr *address,
           socklen_t address_len);

DESCRIPTION         top

       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         top

       Upon successful completion, bind() shall return 0; otherwise, −1
       shall be returned and errno set to indicate the error.

ERRORS         top

       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         top

       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         top

       An application program can retrieve the assigned socket name with the
       getsockname() function.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       connect(3p), getsockname(3p), listen(3p), socket(3p)

       The Base Definitions volume of POSIX.1‐2008, sys_socket.h(0p)

COPYRIGHT         top

       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 .

IEEE/The Open Group                 2013                            BIND(3P)

Pages that refer to this page: netdb.h(0p)sys_socket.h(0p)sys_un.h(0p)accept(3p)connect(3p)getpeername(3p)getsockname(3p)getsockopt(3p)setsockopt(3p)socket(3p)