Tab reaches the disk

Paths and programs, which is the half that makes it worth having. The first word
of a line is a command or a PROGRAM, offered under the name somebody would type
- the extension taken off - and anything after it is a file, offered as it
really is. A separator anywhere in the word says which directory to look in.

A directory answers with a separator on the end instead of a space, which says
what it is and lets the next part be typed straight away. The answer ending in
one is also what stops a space being added, so that is one test rather than a
flag.

PROGRAMS ARE LOOKED FOR WHERE THE SHELL WOULD LOOK to run one: where you are,
/Apps on the disk you are on, and /Apps on drive 0. Offering something the shell
would not find would be finishing a word into a thing that then does not work.
Drive 0's is skipped when that is already the drive, or every program in it
would be offered twice and nothing would ever be the only match.

Walking somebody else's directory means standing in it, which is the only way to
walk one here, so where the person was and which drive they were on are put down
first and restored whatever happens.

Three bugs, all found by running it:

THE DIRECTORY TEST WAS INVERTED. dir asks the same question the same way round
four hundred lines further up, which is what made it obvious once looked at.

THE /Apps WALK OVERWROTE THE TYPED PATH. The whole search runs a second time to
list the matches, and by then TabDir said "/Apps" - so a word that had named
nowhere went looking in the wrong place and listed nothing at all. Two ways into
the walk now, and the typed path is never written over.

AND LISTING ONLY KNEW ABOUT COMMANDS, because it was a second copy of the walk.
It is the same walk with a flag now: finding the answer and showing the matches
are the same question asked twice.

Also cosmosMonitor, which had been RE-BLESSED INTO MEANINGLESSNESS by the wall
move. It disassembles a loaded program, at an address the input names - and that
address moved a page while the recording was simply re-recorded to whatever came
out, which was a page of zeroes. It is pointed at 5000 again.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW

Tests/expected/cosmosMonitor.out

@@ -9,27 +9,27 @@ there is no such bank
 loaded, starting at 5000
 * b program
 bank 00
-* d 4000
-4000  00       ?
-4001  00       ?
-4002  00       ?
-4003  00       ?
-4004  00       ?
-4005  00       ?
-4006  00       ?
-4007  00       ?
-* x 4000
-4000  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
-4010  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
-4020  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
-4030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
+* d 5000
+5000  47 00 30 00  SETD.0 3000
+5004  72 10        SWI 10
+5006  47 00 30 44  SETD.0 3044
+500A  72 10        SWI 10
+500C  47 00 30 7A  SETD.0 307A
+5010  27 1F        INIB 1F
+5012  72 11        SWI 11
+5014  47 00 30 5D  SETD.0 305D
+* x 5000
+5000  47 00 30 00 72 10 47 00 30 44 72 10 47 00 30 7A  G.0.r.G.0Dr.G.0z
+5010  27 1F 72 11 47 00 30 5D 72 10 47 00 30 7A 72 10  '.r.G.0]r.G.0zr.
+5020  47 00 30 65 72 10 20 72 12 00 00 00 00 00 00 00  G.0er. r........
+5030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
 * b data
 bank 01
-* x 2000
-2000  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
-2010  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
-2020  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
-2030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
+* x 3000
+3000  61 20 70 72 6F 67 72 61 6D 2C 20 6C 6F 61 64 65  a program, loade
+3010  64 20 6F 66 66 20 61 20 64 69 73 6B 2C 20 72 75  d off a disk, ru
+3020  6E 6E 69 6E 67 20 6F 6E 20 74 68 65 20 73 79 73  nning on the sys
+3030  74 65 6D 20 74 68 61 74 20 6C 6F 61 64 65 64 20  tem that loaded 
 * b 2
 bank 02
 * x 0

Tests/expected/cosmosTab.out

@@ -10,24 +10,10 @@ dir  do  drive  delete
 I do not know: d
 > zzzx
 I do not know: zzzx
-> echo here
-here
-> help  help 
-dir          list what is on the disk
-load <file>  read a program off the disk
-run [words]  start what was loaded, and tell it those words
-<name> [words]       look where you are and then in /Apps, and start that
-cd [path]    go to a directory, or to the root with nothing after it
-mkdir <path>         make a directory
-rmdir <path>         remove an empty one
-do <file>    run the lines in a file, which must start with #!
-echo [words] say them
-clear        empty the screen
-delete <file>        take it off the disk
-rename <file> <to>   call it something else
-monitor      look at memory, change it, and jump into it
-help         this
-exit         stop, or leave the monitor if you are in it
+> echo heecho hello.sbx re
+hello.sbx re
+> help  hel
+I do not know: hel
 > exit
 halted
 Execution halted.

Tests/expected/cosmosTabPath.out

@@ -0,0 +1,18 @@
+CosmOS
+> CrCrash zz
+Crash opcode | service | bank | device | blind
+finished
+> SaSayzz
+I do not know: Sayzz
+> cd Apcd Apps/
+/Apps> echo where am I
+where am I
+/Apps> cd /
+> echo Apps/Secho Apps/Say.sbx 
+Apps/Say.sbx 
+> echo /Apps/Cecho /Apps/Copy.sbx 
+/Apps/Copy.sbx 
+> exit
+halted
+Execution halted.
+[exit 0]

Tests/input/cosmosMonitor.in

@@ -3,10 +3,10 @@ b nonsense
 b 9
 load greet.sbx
 b program
-d 4000
-x 4000
+d 5000
+x 5000
 b data
-x 2000
+x 3000
 b 2
 x 0
 s 0 FF

Tests/input/cosmosTabPath.in

@@ -0,0 +1,8 @@
+Cr	zz
+Sa	zz
+cd Ap	
+echo where am I
+cd /
+echo Apps/S	
+echo /Apps/C	
+exit

Tests/manifest

@@ -389,6 +389,17 @@ cosmosHistory        | CosmOS/Source/cosmos.asm           | run      | cosmosHis
 # The last line is the one that says it works on what is actually there rather than on what
 # was typed: two backspaces take "help" down to "he", and Tab finishes it again.
 cosmosTab            | CosmOS/Source/cosmos.asm           | run      | cosmosTab.in       | -     | disks/cosmos.img
+# And the half of it that reaches the disk. A program is offered under the name somebody
+# would type - the extension taken off - because that is what a first word can usefully be;
+# anywhere after the first word everything is offered as it really is. A directory answers
+# with a separator rather than a space, which says what it is and lets the next part be
+# typed straight away.
+#
+# A path in the word says where to look, and the shell looks in the three places it would
+# look to RUN something: where you are, /Apps on the disk you are on, and /Apps on drive 0.
+# Offering what the shell would not find would be finishing a word into something that then
+# does not work.
+cosmosTabPath        | CosmOS/Source/cosmos.asm           | run      | cosmosTabPath.in   | -     | disks/cosmos.img
 # The same editing offered to a PROGRAM, through osReadLine. Edit reads its lines that way,
 # so a word typed with two letters the wrong way round is put right without starting the line
 # again - which is the whole of what A4 buys.