# nng_socket_pair

## NAME

nng_socket_pair --- create a connected pair of BSD sockets

## SYNOPSIS

```c
#include <nng/nng.h>

int nng_socket_pair(int fds[2]);
```

## DESCRIPTION

The `nng_socket_pair` function creates a pair of connected BSD sockets.
These sockets, which are returned in the _fds_ array, are suitable for
use with the [BSD socket transport][socket].

On POSIX platforms, this is a thin wrapper around the standard `socketpair` function,
using the {{i:`AF_UNIX`}} family and the `SOCK_STREAM` socket type.
{{footnote: At present only POSIX platforms implementing `socketpair` support this function.}}

> [!TIP]
> This function may be useful for creating a shared connection between a parent process and
> a child process on UNIX platforms, without requiring the processes use a shared filesystem or TCP connection.

## RETURN VALUES

This function returns 0 on success, and non-zero otherwise.

## ERRORS

- `NNG_ENOMEM`: Insufficient memory exists.
- `NNG_ENOTSUP`: This platform does not support socket pairs.

## SEE ALSO

[BSD Socket Transport][socket]

[socket]: ../../tran/socket.md