dup,dup2

   Allocate a new descriptor that refers to a file specified by a
   file descriptor returned by open, creat, or pipe.

   Format

     #include  <unistd.h>

     int dup  (int file_desc1);

     int dup2  (int file_desc1, int file_desc2);
 

Additional information available:

Arguments       Description     Return_Values