# PR_RecvFrom

Receives bytes from a socket and stores the sending peer's address.

## Syntax

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

PRInt32 PR_RecvFrom(
  PRFileDesc *fd,
  void *buf,
  PRInt32 amount,
  PRIntn flags,
  PRNetAddr *addr,
  PRIntervalTime timeout);
```

### Parameters

The function has the following parameters:

`fd`

: A pointer to a {ref}`PRFileDesc` object representing a socket.

`buf`

: A pointer to a buffer containing the data received.

`amount`

: The size of `buf` (in bytes).

`flags`

: This obsolete parameter must always be zero.

`addr`

: A pointer to the {ref}`PRNetAddr` object that will be filled in with the
  address of the sending peer on return.

`timeout`

: A value of type {ref}`PRIntervalTime` specifying the time limit for
  completion of the receive operation.

### Returns

The function returns one of the following values:

- A positive number indicates the number of bytes actually received.
- The value 0 means the network connection is closed.
- The value -1 indicates a failure. The reason for the failure can be
  obtained by calling {ref}`PR_GetError`.

## Description

{ref}`PR_RecvFrom` receives up to a specified number of bytes from socket,
which may or may not be connected. The operation blocks until one or
more bytes are transferred, a timeout has occurred, or there is an
error. No more than `amount` bytes will be transferred.
{ref}`PR_RecvFrom` is usually used with a UDP socket.