BIND(2)             Linux Programmer's Manual             BIND(2)

NAME
       bind - bind a name to a socket

SYNOPSIS
       #include <sys/types.h>
       #include <sys/socket.h>

       int   bind(int   sockfd,  struct  sockaddr  *my_addr,  int
       addrlen);

DESCRIPTION
       bind gives the socket sockfd the  local  address  my_addr.
       my_addr  is  addrlen  bytes  long.  Traditionally, this is
       called "assigning a name to a socket."  (When a socket  is
       created with socket(2), it exists in a name space (address
       family) but has no name assigned.)

       Before a SOCK_STREAM socket is put into the  LISTEN  state
       to receive connections, you usually need to first assign a
       local address using bind to make the socket visible.

NOTES
       Binding a name that is not in the  abstract  namespace  in
       the  UNIX  domain creates a socket in the file system that
       must be deleted by the caller when it is no longer  needed
       (using unlink(2)).

       The  rules used in name binding vary between communication
       domains.  Consult the manual  entries  in  section  4  for
       detailed information. For IP see ip(4) and for PF_UNIX see
       unix(4).  If you want to listen to every  local  interface
       for  IPv4 set the sin_addr member of the IP-specific sock-
       addr_in to INADDR_ANY.  For IP  only  one  socket  may  be
       bound  to  a  specific  local address/port pair. For TCP a
       bound  local  socket  endpoint  (address/port   pair)   is
       unavailable for some time after closing the socket, unless
       the SO_REUSEADDR flag is set. Note that carelessly setting
       SO_REUSEADDR might make TCP more unreliable unless PAWS is
       used (see tcp(4)); the delay is needed to handle old pack-
       ets still in the network.

       IP  sockets  may  also  bind  to  a broadcast or multicast
       address.

RETURN VALUE
       On success, zero is returned.  On error, -1  is  returned,
       and errno is set appropriately.

ERRORS
       EBADF   sockfd is not a valid descriptor.

       EINVAL  The  socket  is already bound to an address.  This
               may change in the  future:  see  linux/unix/sock.c
               for details.

       EACCES  The  address is protected, and the user is not the
               super-user.

       ENOTSOCK
               Argument is a descriptor for a file, not a socket.

       The following errors are specific to UNIX domain (AF_UNIX)
       sockets:

       EINVAL  The addrlen is wrong, or the socket was not in the
               AF_UNIX family.

       EROFS   The  socket inode would reside on a read-only file
               system.

       EFAULT  my_addr  points  outside  the  user's   accessible
               address space.

       ENAMETOOLONG
               my_addr is too long.

       ENOENT  The file does not exist.

       ENOMEM  Insufficient kernel memory was available.

       ENOTDIR A component of the path prefix is not a directory.

       EACCES  Search permission is denied on a component of  the
               path prefix.

       ELOOP   Too   many  symbolic  links  were  encountered  in
               resolving my_addr.

BUGS
       The transparent proxy options are not described.

CONFORMING TO
       SVr4, 4.4BSD (the bind  function  first  appeared  in  BSD
       4.2).   SVr4  documents  additional EADDRNOTAVAIL, EADDRI-
       NUSE, and ENOSR general error conditions,  and  additional
       EIO, EISDIR and EROFS Unix-domain error conditions.

SEE ALSO
       accept(2),   connect(2),  listen(2),  socket(2),  getsock-
       name(2), ip(4), socket(4)

Linux 2.2                   3 Oct 1998                          1