3447 return wcs.err->status;
3450 In
this example,
if an error was generated in one of the
prjset() functions,
3451 wcsperr() would print an error traceback starting with
wcsset(), then
3452 celset(), and finally the particular projection-setting function that
3453 generated the error. For each of them it would print the status return value,
3454 function name, source file, line number, and an error message which may be
3455 more specific and informative than the general error messages reported in the
3456 first example. For example, in response to a deliberately generated error,
3457 the @c twcs test program, which tests
wcserr among other things, produces a
3458 traceback similar to this:
3460 ERROR 5 in
wcsset() at line 1564 of file wcs.c:
3461 Invalid parameter value.
3462 ERROR 2 in
celset() at line 196 of file cel.c:
3463 Invalid projection parameters.
3464 ERROR 2 in
bonset() at line 5727 of file prj.c:
3465 Invalid parameters for Bonne's projection.
3468 Each of the @ref structs "structs" in @ref overview "WCSLIB" includes a
3469 pointer, called @a err, to a
wcserr struct. When an error occurs, a struct is
3470 allocated and error information stored in it. The
wcserr pointers and the
3471 @ref memory "memory" allocated for them are managed by the routines that
3475 example above. If enabled, when an error occurs it is the user's
3476 responsibility to free the memory allocated for the error message using
3478 out of scope will result in memory leaks (if execution continues beyond the