gbos - a tiny Unix-flavored OS for the Game Boy Color (kernel, shell, coreutils in C, RAM filesystem) https://git.sl0p.foo/gbos.git/atom/usr/rev.c?h=master 2026-09-24T20:45:04Z 2026-09-24T20:45:04Z user user@clank 2026-09-24T20:45:04Z urn:sha1:4cd933009dd6ce87fe710acfca6b1f786d51040c /# ls -l /bin > b /# cut -d \s -f 1 b | uniq -c 52 - - touch FILE...: gbfs has no timestamps (an MBC5 cart has no RTC), so touch does the half that means something here - make an empty file. O_APPEND is exactly right: it creates, and it does not truncate what is already there. - tr [-d] SET1 [SET2]: ranges (a-z), -d to delete, and a short SET2 padded with its last character, like tr(1). ASCII only - a 128-entry map. - rev, uniq [-c]: one line each, from a file or stdin like the other filters. Two things the tests caught. A bare "-" is a SET, not a flag, so `tr . -` has to skip flag-matching only when a letter follows the dash. And uniq compared an empty "line" against the last run at EOF and flushed a phantom blank one - a stray "1" in uniq -c output. tr and cut also take \s \t \n \r escapes, because the shell has no quoting: `-d ' '` arrives as three tokens, so a space or tab delimiter was simply untypeable. Shell quoting would be the better fix; this makes the tools usable today without touching the parser. Banks 49-53; 10 program slots left in the 1 MB ROM.