---
name: "bind"
section: "2freebsd"
platform: "linux"
package: "freebsd-manpages"
version: "12.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/bind/2freebsd"
---

# bind(2freebsd)

assign a local protocol address to a socket

## NAME

**bind** – assign a local protocol address to a socket

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<sys/socket.h\>**

*int*\

**bind**(*int s*, *const struct sockaddr \*addr*, *socklen\_t addrlen*);

## DESCRIPTION

The **bind**() system call assigns the local protocol address to a socket. When a socket is created with [socket(2)](/socket/2.md) it exists in an address family space but has no protocol address assigned. The **bind**() system call 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)](/unlink/2.md)).

The rules used in address binding vary between communication domains. Consult the manual entries in section 4 for detailed information.

For maximum portability, you should always zero the socket address structure before populating it and passing it to **bind**().

## RETURN VALUES

The **bind()** function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

## ERRORS

The **bind**() system call will fail if:

- \[EAGAIN\]

  Kernel resources to complete the request are temporarily unavailable.

- \[EBADF\]

  The *s* argument is not a valid descriptor.

- \[EINVAL\]

  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.

- \[EINVAL\]

  The *addrlen* argument is not a valid length for the address family.

- \[ENOTSOCK\]

  The *s* argument is not a socket.

- \[EADDRNOTAVAIL\]

  The specified address is not available from the local machine.

- \[EADDRINUSE\]

  The specified address is already in use.

- \[EAFNOSUPPORT\]

  Addresses in the specified address family cannot be used with this socket.

- \[EACCES\]

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

- \[EFAULT\]

  The *addr* argument 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.

- \[EINTEGRITY\]

  Corrupted data was detected while reading from the file system.

- \[EROFS\]

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

- \[EISDIR\]

  An empty pathname was specified.

## SEE ALSO

[connect(2)](/connect/2.md), [getsockname(2)](/getsockname/2.md), [listen(2)](/listen/2.md), [socket(2)](/socket/2.md)

## HISTORY

The **bind**() system call appeared in 4.2BSD.