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

 int main() {
   int rc;
   printf( "ONE\n" );
   fprintf( stderr, "ERROR: ONE\n" );
   rc = dup2( 1, 2 );  // redirect 2 to 1
   printf( "TWO\n" );
   fprintf( stderr, "ERROR: TWO\n" );
   rc = dup2( 2, 1 );
   printf( "THREE\n" );
   fprintf( stderr, "ERROR: THREE\n" );
   close( 1 );
   printf( "FOUR\n" );
   fprintf( stderr, "ERROR: FOUR\n" );
   return 0;
 }