bind - bind a name to a socket
int bind(int sockfd, struct sockaddr *my_addr, int
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.
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
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
On success, zero is returned. On error, -1 is returned,
and errno is set appropriately.
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
Argument is a descriptor for a file, not a socket.
The following errors are specific to UNIX domain (AF_UNIX)
EINVAL The addrlen is wrong, or the socket was not in the
EROFS The socket inode would reside on a read-only file
EFAULT my_addr points outside the user's accessible
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
ELOOP Too many symbolic links were encountered in
The transparent proxy options are not described.
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.
accept(2), connect(2), listen(2), socket(2), getsock
name(2), ip(4), socket(4)