BIND(2)

NAME
bind - assign a local protocol address to a socket.

LIBRARY
libc

SYNOPSIS
#include <sys/types.h>
#include <sys/socket.h>
int
bind(int s, const struct sockaddr *addr, socklen_t addrlen);

DESCRIPTION
Bind() assigns the local protocol address to a socket. When a socket is created with socket(2) it exists in an address family space but has no protocol address assigned. Bind() requests that addr be assigned to the socket.

NOTES
Binding an address 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 address binding vary between communication domains. Consult the manual entries in section 4 for detailed information.

IMPLEMENTATION NOTES

In the non-threaded library bind() is implemented as the bind syscall.

In the threaded library, the bind syscall is assembled to _thread_sys_bind() and bind() is implemented as a function which locks s for read and write, then calls _thread_sys_bind(). Before returning, bind() unlocks s.

RETURN VALUES
If the bind is successful, a 0 value is returned. A return value of -1 indicates an error, which is further specified in the global errno.

ERRORS
The bind() call will fail if:

[EAGAIN]
    Kernel resources to complete the request are temporarily unavilable.

[EBADF]
    S is not a valid descriptor.

[ENOTSOCK]
    S is not a socket.

[EADDRNOTAVAIL]
    The specified address is not available from the local machine.

[EADDRINUSE]
    The specified address is already in use.

[EACCES]
    The requested address is protected, and the current user has inadequate permission to access it.

[EFAULT]
    The addr parameter is not in a valid part of the user address space.

The following errors are specific to binding addresses in the UNIX domain.

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

[ENAMETOOLONG]
    A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.

[ENOENT]
    A prefix component of the path name does not exist.

[ELOOP]
    Too many symbolic links were encountered in translating the pathname.

[EIO]
    An I/O error occurred while making the directory entry or allocating the inode.

[EROFS]
    The name would reside on a read-only file system.

[EISDIR]
    An empty pathname was specified.

SEE ALSO
connect(2), getsockname(2), listen(2), socket(2)

HISTORY
The bind() function call appeared in 4.2BSD.