BIND(2) | System Calls Manual | BIND(2)

# NAME

`bind` — bind a name to a socket

# SYNOPSIS

`#include <sys/socket.h>`

int
`bind`(int s, const struct sockaddr *name, socklen_t namelen);

# DESCRIPTION

`bind`() assigns a name to an unnamed socket. When a socket is created with socket(2), it exists in a name space (address family) but has no name assigned. `bind`() requests that name be assigned to the socket. namelen indicates the amount of space pointed to by name, in bytes; the sa_len member of name is ignored.

# NOTES

Binding a name 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.

# RETURN VALUES

Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

# ERRORS

The `bind`() function will fail if:

[`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.
[`EINVAL`]
  The socket is already bound to an address, or namelen is not a valid length for the supplied address.
[`EAFNOSUPPORT`]
  The family of the socket and that requested in name->sa_family are not equivalent.
[`ENOBUFS`]
  Insufficient buffer space is available.
[`EACCES`]
  The requested address is protected, and the current user has inadequate permission to access it.
[`EFAULT`]
  The name parameter is not in a valid part of the user address space.

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

[`ENOTDIR`]
  A component of the path prefix is not a directory.
[`ENAMETOOLONG`]
  A component of a pathname exceeded `NAME_MAX` characters, or an entire pathname (including the terminating NUL) exceeded `PATH_MAX` bytes.
[`ENOENT`]
  A prefix component of the pathname 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)

# STANDARDS

The `bind`() function conforms to IEEE Std 1003.1-2008 (“POSIX.1”).

# HISTORY

The `bind`() system call first appeared in 4.1cBSD.

March 31, 2022 | Debian