A program can say how it went

SWI osExit takes a status in A, and the shell keeps it. Fifty eight exits
across twenty three programs now say deliberately whether they worked: 25
did what they were asked, 24 did not, 9 were asked wrongly. Compare is the
exception and says so - one there means the files differ, which is a result
rather than a failure, the way diff has always had it.

IN A RATHER THAN Q, which is not a departure from the rule that a service
answers in Q. This one takes an ARGUMENT, the way osPrintNumber takes A and
B, and it never returns to answer anything. A is free precisely because a
return would have put it back - and Q is the ALU's output, so a small
number costs four instructions there against one in A.

The shell does not print it. A program that failed has already said so in
words and a number beside that is noise, so osLastStatus hands it back and
Status is the program that shows it. That indirection is the point: the
number exists for the thing that cannot read words.

MARKING THE EXITS FOUND A DEFECT ON THE FIRST RUN. Type and More printed
why they had failed and then fell through into the success exit, reporting
that all was well. Nobody had noticed, because while the only reader was a
person, the person could see both the complaint and the claim.

Two smaller things. Snake sets the console to line mode and then exits with
zero, and the linter flagged the second RSTA as redundant - an exit status
and a console mode, equal by accident, which is the class that must never
be collapsed. And the README still taught answering by writing into the
frame, three months of habit that SRET replaced yesterday; that section is
gone and the one describing SRET stands in its place.

Tests/expected/cosmosBreak.out

@@ -5,7 +5,7 @@ break at 4016
 A 11 B 22 Q 00 status 00 
 DP0 2030 DP1 2000 DP2 2037 DP3 4000 SP FFFF
 press a key 
-break at 4033
+break at 4034
 A 44 B 55 Q 00 status 00 
 DP0 2000 DP1 2037 DP2 2030 DP3 4000 SP FFF5
 press a key 

Tests/expected/cosmosClaim.out

@@ -2,7 +2,7 @@ CosmOS
 > claiming more than was reserved was refused
 and the size it really came to was taken
 finished
-> Claim.sbx               572
+> Claim.sbx               580
 claim.dat               266
 2 files
 > halted

Tests/expected/cosmosCwd.out

@@ -3,7 +3,7 @@ CosmOS
 A                       <dir>
 B                       <dir>
 0 files, 3 directories
-> /A> Say.sbx                 52
+> /A> Say.sbx                 53
 notes.txt               25
 2 files
 /A> these are the notes in A

Tests/expected/cosmosInvoke.out

@@ -5,8 +5,8 @@ finished
 finished
 > it says: once more
 finished
-> Say.sbx                 155
-dir.sbx                 155
+> Say.sbx                 156
+dir.sbx                 156
 notes.txt               21
 notes.sbx               21
 4 files

Tests/expected/cosmosMonitor.out

@@ -14,7 +14,7 @@ CosmOS
 4014  47 00 20 5D  SETD.0 205D
 * 4000  47 00 20 00 72 10 47 00 20 44 72 10 47 00 20 7A  G. .r.G. Dr.G. z
 4010  27 1F 72 11 47 00 20 5D 72 10 47 00 20 7A 72 10  '.r.G. ]r.G. zr.
-4020  47 00 20 65 72 10 72 12 00 00 00 00 00 00 00 00  G. er.r.........
+4020  47 00 20 65 72 10 20 72 12 00 00 00 00 00 00 00  G. er. r........
 4030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
 * bank 01
 * 2000  61 20 70 72 6F 67 72 61 6D 2C 20 6C 6F 61 64 65  a program, loade

Tests/expected/cosmosRun.out

@@ -1,12 +1,12 @@
 CosmOS
 > nothing is loaded
-> greet.sbx               210
-hello.sbx               52
-Life.sbx                1409
-Snake.sbx               2167
-Keys.sbx                663
-Say.sbx                 155
-Break.sbx               148
+> greet.sbx               211
+hello.sbx               53
+Life.sbx                1410
+Snake.sbx               2168
+Keys.sbx                664
+Say.sbx                 156
+Break.sbx               149
 notes.txt               21
 8 files
 > load what?

Tests/expected/cosmosSlowDisk.out

@@ -1,11 +1,11 @@
 CosmOS
-> greet.sbx               210
-hello.sbx               52
-Life.sbx                1409
-Snake.sbx               2167
-Keys.sbx                663
-Say.sbx                 155
-Break.sbx               148
+> greet.sbx               211
+hello.sbx               53
+Life.sbx                1410
+Snake.sbx               2168
+Keys.sbx                664
+Say.sbx                 156
+Break.sbx               149
 notes.txt               21
 8 files
 > loaded, starting at 4000

Tests/expected/cosmosStatus.out

@@ -0,0 +1,16 @@
+CosmOS
+> it says: it worked
+finished
+> the last program left 0, which is: it did what it was asked
+finished
+> type: give me a file name
+finished
+> the last program left 2, which is: it was asked wrongly
+finished
+> type: cannot find the file, error 2
+finished
+> the last program left 1, which is: it did not
+finished
+> halted
+Execution halted.
+[exit 0]

Tests/expected/cosmosTreeWrite.out

@@ -1,13 +1,13 @@
 CosmOS
 > Folder                  <dir>
-Edit.sbx                1983
+Edit.sbx                1986
 1 file, 1 directory
 > loaded, starting at 4000
 > note.txt, 0 lines
 > : : : > written, 67 bytes
 > finished
 > Folder                  <dir>
-Edit.sbx                1983
+Edit.sbx                1986
 note.txt                67
 2 files, 1 directory
 > halted