How to redirect the output back to the screen after freopen("out.txt", "a", stdout)

c posix stdout
Hoffmann picture Hoffmann · Dec 15, 2009 · Viewed 37.3k times · Source 
#include <stdio.h>

int main() {
    printf("This goes to screen\n");
    freopen("out.txt", "a", stdout);
    printf("This goes to out.txt");
    freopen("/dev/stdout", "a", stdout);
    printf("This should go to screen too, but doesn't\n");

    return 0;
}

I call freopen to redirect the stdout to out.txt then I print something on the file, now I want to redirect it back to the screen, but freopen("/dev/stdout", "a", stdout); doesn't work. Is there any way to do that using ANSI C or POSIX system calls?

Answer

Patrick Niedzielski picture Patrick Niedzielski · Dec 15, 2009

I can't think of a way to do this in a cross-platform manner, but on GNU/Linux systems (and maybe other POSIX-compliant ones, too) you can freopen ("/dev/tty", "a", stdout). Is this what you were trying to do?

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