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# 1. Motivation

- 1983
- over 500 system calls × multiple errors = 8 bits of errno ?!? ; slide
- disconnect:
  - the user has no idea
  - the kernel knows
- The car is up on the hoist, and we are locking at the underside.
  Mud, crud, and ugly (functional, but ugly).

## 1.1 Error Messages as Finesse

- each is < 1% of project effort
- user benefit exceeds effort
- what the errors look like to the user
  - segfault; slide
  - can't open file; slide
  - perror("open"); slide
  - perror(filename); slide
  - "open %s: %s", filename, strerror; slide

## 1.2 Limitations of perror and strerror

- describes the error number; slide
- the kernel knows; slide
- the file name problem; slide
- 1980s, PDP11, no resources

## 1.3 Level Infinity Support

- Never ever talk to users; slide
- Test team need translations; slide
- Level 1 help desk need translations
- Enough! ; slide