C redirect stdout and stderr to syslog using logger command

main.c

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

int main()
{
    // Pipe open logger command in another process (sh -c logger)
    FILE *fl;
    fl = popen("logger","w");
    if(fl == NULL)
        return 1;

    // Test syslog event
    fprintf(fl,"logger test new\n");//this goes to /var/log/syslog
    fflush(fl);

    // Get the file descriptor number of the output of logger
    int nf;
    nf = fileno(fl);

    // Create backup copy of stdout and stderr
    int stdout_copy = dup(STDOUT_FILENO);
    int stderr_copy = dup(STDERR_FILENO);

    // Duplicate file descriptors using the previous number
    dup2(nf,STDOUT_FILENO);
    dup2(nf,STDERR_FILENO);
    // Disable buffering for stdout and stderr (no flush needed)
    setbuf (stdout,NULL);
    setbuf (stderr,NULL);

    // Test stdout and stderr in syslog
    fprintf(stdout,"Wriiten in stdout\n");
    fprintf(stderr,"Wriiten in stderr\n");

    // Restore stdout and stderr file descriptors
    dup2(stdout_copy, STDOUT_FILENO);
    dup2(stderr_copy, STDERR_FILENO);
    close(stdout_copy);
    close(stderr_copy);

    // Wait for the associated logger process to terminate
    pclose(fl);

    return 0;
}