UI/UX design - suggestions welcome!

[JoshMcguigan]

This is a general issue to discussion ideas/comments regarding the user experience of backlight - primarily focused on the CLI for now. See #4 for discussion of a backlight library / API.

The general philosophy of the current implementation is to trace everything by default, and when the user starts filtering remove everything that isn't explicitly asked for. I think this provides a reasonable balance of discoverability and control.

I'll start things off with some questions/thoughts I've had so far:

• Are the current CLI short flags a good choice (this can easily get bikeshed-y but meh)?
• Should we try to mimic the ltrace API, or move away from it?
• How to best help the user when they add library or syscall filters?
  • What if they filter by a library function that never gets linked? We have to be careful here because the tracee could always dlopen/dlsym and call something at runtime based on some condition which we don't always see
• I often don't care about tracing anything before main
  • There should at least be an option for this, but perhaps it should be the default?
• Filters currently require an exact match, should they be assumed *SEARCH_TERM*?
  • Or should we support regex or some other format? (I think ltrace does something fancy here)
• Currently backlight has a subcommand trace, which is for now the only subcommand and thus redundant - should this be removed? Or else what other subcommands might there be?

I'm open to feedback on any of the above, as well as any new thoughts/opinions!

[pothos]

I think the current behavior makes sense. However, I also think a way to suppress certain events would be good while still tracing all other events (unless a filter is set).
In addition I think that an aggregation mode would be nice to have to get an overview without having to suppress a long list of events that come too often. The aggregation mode could count the events that happen per second (or a configurable duration) and then print them delayed with annotations of how often they have been seen.