Redirecting stdout to a file in C through code

Question

I am outputting to stdout. How can I redirect that to a new file through code? While we run the program we can redirect like ./sample > test.txt. How can I do this when executing the sample program itself ? (C programming)

Answer 1

Use freopen().

Answer 2

Use dup2() system call and redirect the output to a file.

Answer 3

You probably want to use freopen.

Example from reference:

#include <stdio.h>
...
FILE *fp;
...
fp = freopen ("/tmp/logfile", "a+", stdout);