3381 return wcs.err->status;
3384 In
this example,
if an error was generated in one of the
prjset() functions,
3385 wcsperr() would print an error traceback starting with
wcsset(), then
3386 celset(), and finally the particular projection-setting function that
3387 generated the error. For each of them it would print the status return value,
3388 function name, source file, line number, and an error message which may be
3389 more specific and informative than the general error messages reported in the
3390 first example. For example, in response to a deliberately generated error,
3391 the @c twcs test program, which tests
wcserr among other things, produces a
3392 traceback similar to this:
3394 ERROR 5 in
wcsset() at line 1564 of file wcs.c:
3395 Invalid parameter value.
3396 ERROR 2 in
celset() at line 196 of file cel.c:
3397 Invalid projection parameters.
3398 ERROR 2 in
bonset() at line 5727 of file prj.c:
3399 Invalid parameters for Bonne's projection.
3402 Each of the @ref structs "structs" in @ref overview "WCSLIB" includes a
3403 pointer, called @a err, to a
wcserr struct. When an error occurs, a struct is
3404 allocated and error information stored in it. The
wcserr pointers and the
3405 @ref memory "memory" allocated for them are managed by the routines that
3409 example above. If enabled, when an error occurs it is the user's
3410 responsibility to free the memory allocated for the error message using
3412 out of scope will result in memory leaks (if execution continues beyond the