open (OUTC, ">treefuncs.c") || die ("Can't open treefuncs.c");
open (OUTH, ">treefuncs.h") || die ("Can't open treefuncs.h");
open (OUTC, ">treefuncs.c") || die ("Can't open treefuncs.c");
open (OUTH, ">treefuncs.h") || die ("Can't open treefuncs.h");