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Commits
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d9ebc76cf5 |
A script is given words, and keeps them
"do build.sh cosmos.asm" looked for a file called "build.sh cosmos.asm", because scriptOpen copied the whole rest of the line into the name. So a script could be told nothing, and a launcher - a script whose entire job is to hand on what it was told - could not exist. Now the name is cut off the front and what follows is kept whole. $1 to $9 are the words of it, walked out on demand, and $args is all of them. Nothing is stored per parameter, so there is no limit on how many a script may be handed and no second number to keep in step. Both ways of starting a script pass them on: "do" and typing the name. A word that was not given is an error that stops the script, like every other name this shell does not know. Expanding it to nothing would let a command run with an argument missing and then report success, which is what stop-on-failure exists to prevent. $args is always set inside a script, empty if it was given nothing, so "if same $args" can be asked. ---- And the count that describes the block was already wrong ---- Found while adding a field to it. The state one script keeps for another is saved by a single copy of a fixed number of bytes, and that number was 71 against a block of 77: six bytes of line position had been added in the middle of it years after the count was written. So the tail of every saved script was never saved, and #quiet in a helper stayed behind in the script that called it - the opposite of what this file's own comment promises and the README documents. The unsaved line position turned out not to matter, because a loop keeps its own copy in the block record. Nothing said so. Three numbers describe this block and all three now say so in a comment, and cosmosScriptNest ends on a helper that goes quiet and a caller that must not stay that way. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW |
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736037462e |
The shell edits the line it is given
Three different things used to do this job, and which one you got depended on where the machine was running. On a terminal the host held the line and did the echoing and the backspacing; behind a window the console's own gatherer did it; from a file nothing did it at all. One job, three implementations, none of them in the system - which is why there was no way to move about in a line and nowhere for a history to live. So editLine does it. Key mode while a line is being read and line mode straight after, so nothing else in the system and no program calling osReadLine notices anything changed. Left and Right, Home and End, Backspace for the character before the cursor and Delete for the one under it, and anything typed goes in where the cursor is with the rest of the line moving along. Ctrl-D means the end of input again, on an empty line, because that was a thing the terminal did while it was holding the line and it is not holding it now. Same trade as the echoing. MOST KEYSTROKES DRAW NOTHING BUT THEMSELVES. A character typed at the end of a line needs no cursor moved: printing it is the whole change, and a backspace there is three ordinary bytes. That matters beyond speed - moving the cursor by hand is what a terminal is TOLD about, in an escape sequence, so redrawing on every keypress would fill every recorded transcript in this suite with them. The line is only reprinted when something happened in the middle of it. Where the line STARTS is worked out backwards from where printing ended, rather than trusted from what was remembered. That is what makes it survive the screen scrolling: a line printed on the bottom row moves everything up by one, and a remembered row would be one too low from then on. The command line holds 127 characters, up from 63. The limit started to be felt the moment a line could be moved about in. 58 recordings changed, and every one of them by the echo. THE PROOF IS NOT A HEURISTIC: a CosmOS built with the echo silenced reproduces 187 of the 188 recordings byte for byte. The one exception is cosmosTyped, the backspace test, where the rub-out marks now come from the shell instead of from the console's gatherer - same marks, different author. cosmosEditKeys is the new test, and every line in it is typed wrong and then corrected with a different key. Its last line is eighty six characters at a prompt in column two on an eighty column screen, so the line runs onto the row below and the shell has to find the start of something it can no longer see; breaking either half of that arithmetic fails it. Also: agree.sh looked for "> the same", anchored to a prompt that no longer precedes what a command prints. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW |
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c28826df77 |
Let a script run a script, four deep
A build script calling a setup script is the first thing anybody tries. What is saved when one script starts another is A POSITION AND NOT A BUFFER: the name, which block comes next, how many are left, and where in the block it had got to. Seventy bytes, and they sit next to each other in the data segment on purpose so that saving them is one copy. The block itself is read again on the way back, which costs one disk read per return and saves 257 bytes a level - the inner script reads its own block into the single buffer there is, so coming back means fetching the outer one's block again and landing on the byte it left. The slot is reached by stepping rather than by multiplying, because this machine has no multiply and the depth is never more than three steps. Four levels. Deep enough for a script calling a script that calls a helper, shallow enough that a script running itself says so rather than filling memory. A line that fails now stops every level and not just the innermost, because a build whose helper failed should not carry on in its caller. The caller's place is saved BEFORE the new file is looked at, and put back on every way out that is not success. Opening writes the name into the live state in order to ask the disk about it, so by the time "there is no such file" is known, the caller's place has already been overwritten - a failed 'do' inside a script would otherwise leave the script that ran it reading from a name it never chose. The test resumes in the outer script's SECOND block, which is the case the whole design turns on and the one an ordinary nesting test would miss. Breaking the re-read, the save, or the limit each fails it. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW |