## nng_socket_pair

Create a connected pair of BSD sockets.

### Synopsis

```c
#include <nng/nng.h>
#include <nng/supplemental/util/platform.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 xref:../tran/socket.adoc[_socket_] transport.

On POSIX platforms, this is a thin wrapper around the standard `socketpair` function, using the `AF_UNIX` family and the `SOCK_STREAM` socket type.

NOTE: At present only POSIX platforms implementing `socketpair` are supported with 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

[horizontal]
`NNG_ENOMEM`:: Insufficient memory exists.
`NNG_ENOTSUP`:: This platform does not support socket pairs.

### See Also

xref:../tran/socket.adoc[BSD Socket Transport]
