3481 return wcs.err->status;
3484 In
this example,
if an error was generated in one of the
prjset() functions,
3485 wcsperr() would print an error traceback starting with
wcsset(), then
3486 celset(), and finally the particular projection-setting function that
3487 generated the error. For each of them it would print the status return value,
3488 function name, source file, line number, and an error message which may be
3489 more specific and informative than the general error messages reported in the
3490 first example. For example, in response to a deliberately generated error,
3491 the @c twcs test program, which tests
wcserr among other things, produces a
3492 traceback similar to this:
3494 ERROR 5 in
wcsset() at line 1564 of file wcs.c:
3495 Invalid parameter value.
3496 ERROR 2 in
celset() at line 196 of file cel.c:
3497 Invalid projection parameters.
3498 ERROR 2 in
bonset() at line 5727 of file prj.c:
3499 Invalid parameters for Bonne's projection.
3502 Each of the @ref structs "structs" in @ref overview "WCSLIB" includes a
3503 pointer, called @a err, to a
wcserr struct. When an error occurs, a struct is
3504 allocated and error information stored in it. The
wcserr pointers and the
3505 @ref memory "memory" allocated for them are managed by the routines that
3509 example above. If enabled, when an error occurs it is the user's
3510 responsibility to free the memory allocated for the error message using
3512 out of scope will result in memory leaks (if execution continues beyond the