|
|
- sort [-r] [-n]: everything in RAM, which bounds it - a task has 8 KiB and a
file caps at 3 KiB, so 96 lines of 2400 bytes with room for the stack.
Insertion sort over an index; at that size the simple thing is fast and
costs far less ROM. `uniq -c f | sort -n -r` finally works.
NB the key needs a scratch SLOT of its own: gt() compares table entries, so
reusing slot i as scratch overwrites the entries being shifted into it.
- cmp: reports the first differing byte, silent when the files match. There
was no way to check a copy on the machine - you had to haul both to a host.
- strings [-n N]: pairs with xxd now that /bin/<prog> is readable. It finds
"gbos sm83 (Game Boy Color)" inside /bin/uname.
- du [dir]: 256-byte blocks, the unit df and the filesystem use. Bytes
overflow - /bin alone is 52 x 16 KiB, which wrapped a 16-bit counter and
printed 32768. Recurses by re-opendir'ing, since the kernel keeps only one
"directory being listed" cursor.
- time CMD: 1/64 s resolution from the tick counter. It rebuilds the child's
command line at $A000 - which is its own argument area, so everything is
copied to the stack first.
|
