# How to force writing output files in real-time?
**URL:** https://community.freefem.org/t/how-to-force-writing-output-files-in-real-time/1435
**Category:** General Discussion
**Created:** [January 15, 2022, 6:07pm UTC](https://community.freefem.org/t/how-to-force-writing-output-files-in-real-time/1435 "2022-01-15T18:07:55Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@david.fabre](https://community.freefem.org/u/david.fabre)
#### Post date: [January 15, 2022, 6:07pm UTC](https://community.freefem.org/t/how-to-force-writing-output-files-in-real-time/1435/1 "2022-01-15T18:07:55Z")
Hello all !
One simple question. I use communication files to check the status of freefem programs from Matlab. For this I want to write in such communication files in real-time. I can see that it is usually not the case ; I assume that freefem stores the output in some buffer and writes only when there is a sufficient ammount of things to be written. This leads to some delay, especially in nohup mode.
So is there a way to force the writing (and closing) of files before continuing the program ?
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [January 15, 2022, 7:17pm UTC](https://community.freefem.org/t/how-to-force-writing-output-files-in-real-time/1435/2 "2022-01-15T19:17:04Z")
If you scope the variable definition, it will be written at the end of its lifetime.
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### Author:  [@fivanci](https://community.freefem.org/u/fivanci)
#### Post date: [January 16, 2022, 7:00am UTC](https://community.freefem.org/t/how-to-force-writing-output-files-in-real-time/1435/3 "2022-01-16T07:00:57Z")
Not quite sure if I understood the question well, but how about `flush` it ? E.g., I often do something like this when I want to check the progress before simulation ends:
```auto
// open file in append mode
ofstream file("filename.txt",append);
...
for(...){
... some calculations ...
file << ... << endl; // write in the file
if(...) file.flush; // e.g. flush every five time steps
}
```
Seems to be working well for me.
if
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### Author:  [@david.fabre](https://community.freefem.org/u/david.fabre)
#### Post date: [January 16, 2022, 9:49pm UTC](https://community.freefem.org/t/how-to-force-writing-output-files-in-real-time/1435/4 "2022-01-16T21:49:01Z")
Thanks ! flush seems to be the precise thing I need !
Cheers
D