Very Computer

With such functions like dup2, fcntl, ioctl, I'm supposing you are on a
Unix system, so I followup this post to comp.unix.programmer.
Here is a sample program, I hope it helps you :

#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>

int     main(int argc, char *argv[])

{
        int     stdout_fileno;
        int     null_fileno;

        printf("Hello ");
        printf("world");

        /*
        ** dup & close STDOUT_FILENO
        ** Don't fclose stdout because it could not be reopened
        ** Flushing stdout is necessary because it is line-buffered by
        ** default. If this was not done, the above two strings would be
lost,
        ** because the string "world" is not terminated by a new-line
char.
        */
        fflush(stdout);
        if ((stdout_fileno = dup(STDOUT_FILENO)) < 0) {
                perror("dup");
                exit(EXIT_FAILURE);
        }

        /*
        ** Redirect STDOUT_FILENO to /dev/null to make printf happy
        */
        if ((null_fileno = open("/dev/null", O_WRONLY)) < 0) {
                perror("open");
                exit(EXIT_FAILURE);
        }
        if (dup2(null_fileno, STDOUT_FILENO) < 0) {
                perror("dup2");
                exit(EXIT_FAILURE);
        }
        close(null_fileno);

        printf("Goobye cruel world");

        /*
        ** restore STDOUT_FILENO & close useless stdout_fileno
        ** Flush stdout to clear internal buffer before restoring
        */
        fflush(stdout);
        if (dup2(stdout_fileno, STDOUT_FILENO) < 0) {
                perror("dup2");
                exit(EXIT_FAILURE);
        }
        close(stdout_fileno);

        printf("\nHello, I'm working again\n");
        return(EXIT_SUCCESS);

Quote:}

This program prints :
Hello world
Hello, I'm working again

--
Herve Couppe de Lahongrais (SEU)       | Eurocontrol Experimental Centre