Finding keywords in a FITS keyword list.

    347:    FitsKw findKw(Hdr *, char *name);
    348:    FitsKw findnextKw(Hdr *, char *name);
    349:    FitsKw first(Hdr *);
    350:    FitsKw next(FitsKw);
    351:    FitsKw getKw(Hdr *, int n);
    352:    FitsKw insertfirst(Hdr *);

The ``find'' function starts at the beginning of the list and finds the first occurence of the desired keyword. The ``findnext'' function begins at the current position and returns the next occurence of the keyword. NotFound is returned if no such keyword is found. The ``first'' function sets the current position to the beginning of the list. The ``next'' function sets the position to the next keyword in the list. ``Next'' returns NotFound after the last keyword in the list. ``GetKw'' returns the n-th keyword. The special function ``insertfirst'' is used to position the cursor prior to the first item in the list so that a new keyword may be inserted at the beginning of the list. (Insert functions always insert keywords at a position after the cursor.)