I am now tracking which of Assaf's tests my implementation passes and fails in https://github.com/ericfischer/coreutils/issues/2. The ones that fail seem to be because:
* I have not implemented cut -n * My tr will not remove bytes from the middle of characters * Linux and MacOS disagree about whether nonbreaking space is a space or a graphic character The first of these is clearly my bug that I need to fix. The second I think is arguably an error in the test, because POSIX specifies that octal escapes represent characters, not bytes. The third is a portability problem that should probably be solved by the use of a different character in the test. Eric
