pim
9e0a98ed07
Validate(root): optional startup/test check for tree authoring faults — >1 slot child per node, empty word, duplicate sibling words, dead-end node — traversing circular slots without looping (#3). keypress subpackage: WaitForKey(ctx, cancel) cancels a context on any keystroke for watch-style streaming commands, with per-GOOS cbreak (linux TCGETS/TCSETS, BSD TIOCGETA/TIOCSETA) and a non-tty/unsupported fallback that just waits on ctx. Lifts the last OpenBSD-specific bit out of evpnc/maglevc's watch.go (#6). docs: replace PROPOSAL.md with an RFC-2119 design.md (FR/NFR for the library). Example now dogfoods Validate (a unit test) and keypress (a bounded `watch` command). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
33 lines
1.0 KiB
Go
33 lines
1.0 KiB
Go
// SPDX-FileCopyrightText: (C) Copyright 2026 Pim van Pelt <pim@ipng.ch>
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// SPDX-License-Identifier: Apache-2.0
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//go:build linux
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package keypress
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import "golang.org/x/sys/unix"
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// cbreak puts the terminal into cbreak mode (no canonical input/echo) so a
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// single keystroke is available, leaving output post-processing intact. Linux
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// uses the TCGETS/TCSETS termios ioctls (the BSDs use TIOCGETA/TIOCSETA). It
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// returns the previous termios for restore, or an error if fd is not a tty.
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func cbreak(fd int) (*unix.Termios, error) {
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old, err := unix.IoctlGetTermios(fd, unix.TCGETS)
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if err != nil {
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return nil, err
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}
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t := *old
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t.Lflag &^= unix.ICANON | unix.ECHO | unix.ECHOE | unix.ECHOK | unix.ECHONL
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t.Cc[unix.VMIN] = 1
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t.Cc[unix.VTIME] = 0
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if err := unix.IoctlSetTermios(fd, unix.TCSETS, &t); err != nil {
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return nil, err
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}
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return old, nil
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}
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// restore reverts the terminal to the settings captured by cbreak.
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func restore(fd int, old *unix.Termios) error {
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return unix.IoctlSetTermios(fd, unix.TCSETSF, old)
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}
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