---
name: "rtf_receive"
section: "2"
platform: "linux"
package: "rtlinux"
version: "2.0rel-1"
release: "Debian 2.2 (Potato)"
platforms: ["linux"]
url: "https://new.carta.tech/rtf_receive"
---

# rtf\_receive(2)

get data from an rt\_ipc real-time fifo

## NAME

rtf\_receive - get data from an rt\_ipc real-time fifo

## SYNOPSIS

```
#define MODULE
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/errno.h>
#include <linux/rtf.h>
#include rt_ipc.h
```

**int rtf\_receive(unsigned int** *fifo***, void \****buf***, int** *count***, RTIME** *timeout***)**

## DESCRIPTION

**rtf\_receive** gets data from the rt-fifo *fifo*. The data, up to size *count*, is put into *buf*. If *timeout* is RT\_NO\_WAIT, the function returns immediately even if *count* bytes are not available.  If *timeout* is RT\_WAIT\_FOREVER, the function blocks until *count* bytes are available.  If *timeout* is any other value, it represents the time at which the function will return with a timeout after unsuccessfully waiting for data.  In any case, as many bytes as possible are returned, even if a timeout occurs or RT\_NO\_WAIT is specified.

The rt\_ipc RT-FIFO is a mechanism, implemented as a character device, to communicate between real-time tasks and ordinary Linux processes.  It is based on the Real-Time Linux RT-FIFO mechanism.  The rtf\_\* functions are used by the real-time tasks; Linux processes use standard character device access functions such as **[read(2)](/read/2.md)**, **[write(2)](/write/2.md)**, and **[select(2)](/select/2.md)**.

## RETURN VALUE

If the return value is greater than or equal to zero, it represents the number of bytes received.  This might be less than *count* if the function timed out or RT\_NO\_WAIT was specified and less than *count* bytes were available.  On failure, a negative value is returned as described below.

## ERRORS

- **-ENODEV**

  *fifo* is not less than IPC\_RTF\_NO and RTF\_NO.

- **-EINVAL**

  *fifo* is not a valid fifo identifier.

## AUTHOR

Jerry Epplin \<JerryEpplin@worldnet.att.net\>

## SEE ALSO

[**rtf\_ipc\_create**(2)](/rtf_ipc_create/2.md), [**rtf\_ipc\_destroy**(2)](/rtf_ipc_destroy/2.md), [**rtf\_send**(2)](/rtf_send/2.md)