Be written as a subprogram (not a main) which returns an
integer status value.
(For C only) Contain the following block of code near the
top of the task subroutine:
#include "fitsio.h" /* assuming CFITSIO routines will be called */
#include "pil.h" /* assuming PIL routines will be called */
#define TOOLSUB my_task_subroutine_name /* use actual subroutine name here */
Check return status after all CFITSIO and APE calls and
use the relevant error reporting routine if status is non-zero.
Register a task name and version number (see below).