text: #include <lib.h>
  #define ptrace _ptrace
  #include <unistd.h>
  
  PUBLIC long ptrace(req, pid, addr, data)
  int req, pid;
  long addr, data;
  {
    _M.m2_i1 = pid;
    _M.m2_i2 = req;
    _M.m2_l1 = addr;
    _M.m2_l2 = data;
    if (_callx(MM, PTRACE) == -1) return(-1L);
    if (_M.m2_l2 == -1) {
  	errno = 0;
  	return(-1L);
    }
    return(_M.m2_l2);
  }
  