usr: sort, cmp, strings, du, time

- 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.

1 files changed, 63 insertions, 0 deletions

diff --git a/src/programs.asm b/src/programs.asm
index e9e1be9..96229f4 100644
--- a/src/programs.asm
+++ b/src/programs.asm
@@ -196,6 +196,33 @@ ProgCut:
 SECTION "prog_uniq",   ROMX[$4000], BANK[53]
 ProgUniq:
     INCBIN "build/usr/uniq.bin"
+SECTION "prog_sort",    ROMX[$4000], BANK[54]
+ProgSort:
+    INCBIN "build/usr/sort.bin"
+SECTION "prog_cmp",     ROMX[$4000], BANK[55]
+ProgCmp:
+    INCBIN "build/usr/cmp.bin"
+SECTION "prog_strings", ROMX[$4000], BANK[56]
+ProgStrings:
+    INCBIN "build/usr/strings.bin"
+SECTION "prog_du",      ROMX[$4000], BANK[57]
+ProgDu:
+    INCBIN "build/usr/du.bin"
+SECTION "prog_time",    ROMX[$4000], BANK[58]
+ProgTime:
+    INCBIN "build/usr/time.bin"
+SECTION "prog_clear",   ROMX[$4000], BANK[59]
+ProgClear:
+    INCBIN "build/usr/clear.bin"
+SECTION "prog_ln",      ROMX[$4000], BANK[60]
+ProgLn:
+    INCBIN "build/usr/ln.bin"
+SECTION "prog_ntpdate", ROMX[$4000], BANK[61]
+ProgNtpdate:
+    INCBIN "build/usr/ntpdate.bin"
+SECTION "prog_date",    ROMX[$4000], BANK[62]
+ProgDate:
+    INCBIN "build/usr/date.bin"
 
 ; -----------------------------------------------------------------------------
 ; PROG_SH (bank 3) - the shell, now written in C (usr/sh.c): parses >/</| and
@@ -342,6 +369,24 @@ ProgramTable::
     dw ProgCut
     db LOW(BANK(ProgUniq)), HIGH(BANK(ProgUniq))
     dw ProgUniq
+    db LOW(BANK(ProgSort)), HIGH(BANK(ProgSort))
+    dw ProgSort
+    db LOW(BANK(ProgCmp)), HIGH(BANK(ProgCmp))
+    dw ProgCmp
+    db LOW(BANK(ProgStrings)), HIGH(BANK(ProgStrings))
+    dw ProgStrings
+    db LOW(BANK(ProgDu)), HIGH(BANK(ProgDu))
+    dw ProgDu
+    db LOW(BANK(ProgTime)), HIGH(BANK(ProgTime))
+    dw ProgTime
+    db LOW(BANK(ProgClear)), HIGH(BANK(ProgClear))
+    dw ProgClear
+    db LOW(BANK(ProgLn)), HIGH(BANK(ProgLn))
+    dw ProgLn
+    db LOW(BANK(ProgNtpdate)), HIGH(BANK(ProgNtpdate))
+    dw ProgNtpdate
+    db LOW(BANK(ProgDate)), HIGH(BANK(ProgDate))
+    dw ProgDate
 ProgramTableEnd::
 
 ; -----------------------------------------------------------------------------
@@ -453,4 +498,22 @@ NameTable::
     db PROG_CUT
     db "uniq", 0
     db PROG_UNIQ
+    db "sort", 0
+    db PROG_SORT
+    db "cmp", 0
+    db PROG_CMP
+    db "strings", 0
+    db PROG_STRINGS
+    db "du", 0
+    db PROG_DU
+    db "time", 0
+    db PROG_TIME
+    db "clear", 0
+    db PROG_CLEAR
+    db "ln", 0
+    db PROG_LN
+    db "ntpdate", 0
+    db PROG_NTPDATE
+    db "date", 0
+    db PROG_DATE
     db 0