SYSTEM CALLS
    dup2		- make another descriptor

INVOCATION
    dup2( desc, new )
      int  desc;
      int  new;

EXPLANATION
    The descriptor <desc> is duplicated as descriptor <new>.
    A close(2) is performed on <new> if it was in use.

RESULTS
    >=0 : The new descriptor.
     -1 : Error.

REFERENCES
    close(2), dup(2), open(2)