usr: touch, tr, rev, cut, uniq

    /# 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.

1 files changed, 2 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index b3f1b0e..3f07ec2 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,8 @@ PROGS  := chello echo true false uname pid cat wc head args \
           ls save rm sh ps kill spin blk mkdir count ptest necho \
           wget chat netd ping nslookup dhcp irc uptime ansi \
           grep more cp nc httpd ircd \
-          df mv sleep tee tail help poweroff xxd
+          df mv sleep tee tail help poweroff xxd \
+          touch tr rev cut uniq
 CBLOBS := $(patsubst %,$(BUILD)/usr/%.bin,$(PROGS))
 $(BUILD)/programs.o: $(CBLOBS)