# Get the data from running linux app in real time
**URL:** https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206
**Category:** General
**Created:** [24 February 2020 16:09 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206 "2020-02-24T16:09:55Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@XiaoBin](https://discourse.nodered.org/u/XiaoBin)
#### Post date: [24 February 2020 16:09 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/1 "2020-02-24T16:09:55Z")
Hello all
I am going to get the data on node-red from running app.
The source code I am running is as following.
while(1){
status = bscXfer(&xfer);
if(xfer.rxCnt \> 0 && status \> 0) {
cout \<\< "Received " \<\< xfer.rxCnt \<\< " bytes:\n";
```
for(int i = 0; i < xfer.rxCnt; i++)
{
cout << xfer.rxBuf[i];
}
cout << "\n";
xfer.rxCnt = 0;
}
}
```
This app is working well, but I am going to receive xfer.rxBuf[i] data on node-read in real time while app is running.
I have studied exec node and daemon node for it, but I have not found the solution for it.
Hopefully I want to implement using stdout.
What's the best method for it?
Thank you
---
### Author:  [@afelix](https://discourse.nodered.org/u/afelix)
#### Post date: [24 February 2020 16:13 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/2 "2020-02-24T16:13:17Z")
Have you thought about rather than read/write to/from stdout with the app/node-red, to utilise MQTT and send data from your app to Node-RED over MQTT? You would then run each as separate processes, and can start/stop both without having to keep the other process in mind, nor forking.
If you're not familiar with MQTT, here's a good getting started manual to understand the concept behind it. [https://www.hivemq.com/mqtt-essentials/](https://www.hivemq.com/mqtt-essentials/)
On top of that, there are good C++ libraries available for MQTT.
---
### Author:  [@XiaoBin](https://discourse.nodered.org/u/XiaoBin)
#### Post date: [24 February 2020 16:17 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/3 "2020-02-24T16:17:43Z")
Thank afelix.
This thread is running once per 20 ~ 50ms.
I am wondering that MQTT can support thus timing.
What is your thought for it?
Regards
---
### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [24 February 2020 16:21 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/4 "2020-02-24T16:21:27Z")
> [@XiaoBin](#):
>
> This thread is running once per 20 ~ 50ms.
> I am wondering that MQTT can support thus timing.
Hi, MQTT can support that but it might be a problem for your hardware, which platform are you using?
---
### Author:  [@XiaoBin](https://discourse.nodered.org/u/XiaoBin)
#### Post date: [24 February 2020 16:22 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/5 "2020-02-24T16:22:51Z")
I am using Raspberry PI Zero W.
---
### Author:  [@XiaoBin](https://discourse.nodered.org/u/XiaoBin)
#### Post date: [24 February 2020 16:40 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/6 "2020-02-24T16:40:49Z")
Hello afelix and ghayne
Thank you for your comments.
I think MQTT is good for me, but I am not familiar to it.
What MQTT library for C do you recommendon my application?
Thank you again.
---
### Author:  [@afelix](https://discourse.nodered.org/u/afelix)
#### Post date: [24 February 2020 17:26 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/7 "2020-02-24T17:26:43Z")
> [@XiaoBin](#):
>
> What MQTT library for C do you recommendon my application?
Depending on where you run your application, either use one of the standard Paho MQTT libraries ([regular](https://www.eclipse.org/paho/clients/c/) / [embedded](https://www.eclipse.org/paho/clients/c/embedded/)), or when running on Arduino or ESP8266/ESP32 that deploy through the Arduino IDE, use Nick's [PubSubClient](https://pubsubclient.knolleary.net/).
> [@XiaoBin](#):
>
> I am using Raspberry PI Zero W.
I am really not sure if a Pi Zero will be able to manage this on "every 20 ~ 50ms", while also running other applications on it. That equals between 20 and 50 times a second. The Pi zero series is remarkably slower than other raspberry models, as is to be expected.
---
### Author:  [@XiaoBin](https://discourse.nodered.org/u/XiaoBin)
#### Post date: [25 February 2020 07:50 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/8 "2020-02-25T07:50:24Z")
Thank you afelix
I am considering to IPC(Inter Process Communication) for communication between app and node-red.
I have found node-red-contrib-ipc node for it.
But I have some troubles to create & open the fifo.
Also I am not sure if I can use node-red-contrib-ipc node on my application.
Please let you check my new solution and give me your suggestion.
Thank you.
---
### Author:  [@XiaoBin](https://discourse.nodered.org/u/XiaoBin)
#### Post date: [27 February 2020 15:12 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/9 "2020-02-27T15:12:26Z")
I have used MQTT as ghayne said before, then I resolved it.
Thank you ghayne and afelix.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [12 March 2020 15:12 UTC](https://discourse.nodered.org/t/get-the-data-from-running-linux-app-in-real-time/22206/10 "2020-03-12T15:12:26Z")
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