pim
d63ffd6a3a
Reusable, generics-based CLI extracted from vpp-evpn's cmd/evpnc: a declarative command tree (Node[C]) from which dispatch, '?'-help and TAB-completion are derived, an interactive Shell[C], dynamic slot resolvers (context-dependent via captured args), text-or-JSON output (Emit), and color helpers (Paint/Label/KV). Builds on Linux and OpenBSD (readline termios override). Includes a self-contained example and a design proposal under docs/. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
42 lines
1.5 KiB
Go
42 lines
1.5 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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package cli
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// Bright (high-intensity) ANSI color codes, plus the reset sequence. These are
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// the palette consumed by Paint and Label; status words pop while unremarkable
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// "normal" states can stay uncolored.
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const (
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Reset = "\x1b[0m"
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Red = "\x1b[91m" // bright red
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Green = "\x1b[92m" // bright green
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Blue = "\x1b[94m" // bright blue
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Yellow = "\x1b[93m" // bright yellow
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Cyan = "\x1b[96m" // bright cyan
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)
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// colorEnabled is process-global, toggled once at startup via SetColor. It
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// defaults to false so output is script-safe unless a program opts in.
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var colorEnabled bool
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// SetColor turns colorized output on or off for Paint and Label. Call it once
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// at startup (e.g. from a -color flag): color is useful in an interactive shell
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// but noise when piping one-shot output into scripts.
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func SetColor(on bool) { colorEnabled = on }
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// ColorEnabled reports whether colorization is currently on.
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func ColorEnabled() bool { return colorEnabled }
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// Paint wraps s in an ANSI color when color is enabled; otherwise it returns s
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// unchanged, so the word still reads in scripts and on no-color terminals.
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func Paint(s, code string) string {
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if !colorEnabled {
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return s
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}
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return code + s + Reset
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}
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// Label wraps s in blue when color is enabled. Use it for static field labels —
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// the "key=" half of a "key=value" pair — so the value stands out in normal font.
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func Label(s string) string { return Paint(s, Blue) }
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