2 Error Handling

None of the CHR routines report error messages; i.e. they do not use the Starlink Error Reporting System , ERR (see SUN/104). However, some routines do use the inherited status conventions (described in SUN/104) to indicate success or failure. Those CHR routines which do not have a status argument handle any errors internally and have a specified behaviour on error. Those CHR routines which do have a status argument fall into two categories: those which obey the full inherited status conventions and return without action if given a status value other than SAI__OK, and those which ignore the given status and just return a status value on exit. The following routines obey the full inherited status conventions:

The routines CHR_COPY, CHR_DCWRD and CHR_TRCHR all just return a status set to a value not equal to SAI__OK on error.

The symbolic names of the error values used by CHR are given in Appendix A.