Question

I run a

$ myprogram.exe

which main function signature is int main(int argc, char *argv[])
The program gets one argument as a directory path, and makes some processing to the files in it.
During the processing it prints some results to stdout (or stderr).
I wanted to redirect these results to the file. So I run my program as follow:

$ myprogram.exe C:\dir > res.txt

The results are still printed to the screen and res.txt remains empty.
How can I solve the issue?

Answer 1

Your program probably prints results to standard error stream (stderr), rather than standard output stream (stdout).

To redirect stderr, (which is file descriptor 2), use

myprogram.exe C:\dir 2> res.txt 

If you want to redirect both stdout and stderr, you should redirect them to different files, like

myprogram.exe C:\dir > res.txt 2> errors.txt

or redirect one stream to the other and redirect latter to file

myprogram.exe C:\dir >res.txt 2>&1