# PR_OpenUDPSocket

Creates a new UDP socket of the specified address family.

## Syntax

```{code}
#include <prio.h>

PRFileDesc* PR_OpenUDPSocket(PRIntn af);
```

### Parameters

The function has the following parameters:

`af`

: The address family of the new UDP socket. Can be `PR_AF_INET`
  (IPv4), `PR_AF_INET6` (IPv6), or `PR_AF_LOCAL` (Unix domain,
  supported on POSIX systems only).

### Returns

The function returns one of the following values:

- Upon successful completion, a pointer to the {ref}`PRFileDesc` object
  created for the newly opened UDP socket.
- If the creation of a new UDP socket failed, `NULL`.

## Description

UDP (User Datagram Protocol) is a connectionless, unreliable datagram
protocol of the TCP/IP protocol suite. UDP datagrams may be lost or
delivered in duplicates or out of sequence.

{ref}`PR_OpenUDPSocket` creates a new UDP socket of the address family
`af`. The socket may be bound to a well-known port number with
{ref}`PR_Bind`. Datagrams can be sent with {ref}`PR_SendTo` and received with
{ref}`PR_RecvFrom`. When the socket is no longer needed, it should be
closed with a call to {ref}`PR_Close`.