C API error handling

[v0dro]

I searched the code base but could not find any standardized way in which GR handles errors. Most C libraries that I've worked with in the past return some integer value from functions in case they fail.

What sort of mechanism is followed for this purpose in GR? Am I missing something?

[FlorianRhiem]

The current error handling mostly consists of reporting the error and if there is no way of recovery (e.g. when the system is out of memory), aborting the program.

• For GR errors are reported to stderr, or handled by GKS if the data is simply passed through to it.
• For GKS there is gks_perror and related functions (like gks_report_error and gks_fatal_error) in error.c.
• For GR3 there is gr3_geterror and gr3_geterrorstring, which translate more easily into exceptions in wrappers, e.g. in python-gr.