From 019c576f1dcaa2de2ca0bcf5f27186ad5cd99030 Mon Sep 17 00:00:00 2001
From: Matthieu Jolimaitre <matthieu@imagevo.fr>
Date: Thu, 26 Jun 2025 15:03:27 +0200
Subject: [PATCH] Optimize process management and add terminal scrolling
 functionality

Improved process handling, added go_up option for scrolling the terminal to the
start of the command at each run.
---
 deno.json |  2 +-
 regar.ts  | 29 +++++++++++++++++++++++------
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/deno.json b/deno.json
index cd99b02..a634c3d 100644
--- a/deno.json
+++ b/deno.json
@@ -1,3 +1,3 @@
 {
-    "fmt": { "useTabs": true, "lineWidth": 120 }
+	"fmt": { "useTabs": true, "lineWidth": 120 }
 }
diff --git a/regar.ts b/regar.ts
index d30b5c4..0b188d4 100755
--- a/regar.ts
+++ b/regar.ts
@@ -5,10 +5,10 @@ import { Command } from "https://deno.land/x/cliffy@v1.0.0-rc.4/command/mod.ts";
 import { Channel, Constructible, InstanceOf } from "https://git.barnulf.net/mb/barnulf_ts/raw/branch/master/mod.ts";
 
 async function main() {
-	const { do_clear, command, extensions, files, strategy } = await parse_args();
+	const { do_clear, command, extensions, files, strategy, go_up } = await parse_args();
 	const channel = new Channel<Event>();
 	files.map((path) => new Watcher(path, extensions).spin(channel));
-	new Runner(command, strategy, do_clear).spin(channel);
+	new Runner(command, strategy, do_clear, go_up).spin(channel);
 }
 
 async function parse_args() {
@@ -20,15 +20,18 @@ async function parse_args() {
 		.option("-s, --soft", "Ends the child process by sending an interuption and waiting for it to shut down.")
 		.option("-w, --wait", "Wait for the child process to complete without terminating it. (default)")
 		.option("-e, --extensions <extentions>", "Comma separated whitelist of extensions to whatch.")
-		.option("-c, --clear", "Clear the terminal on restart").parse();
+		.option("-c, --clear", "Clear the terminal on restart.", { default: false })
+		.option("-u, --up", "Scroll the terminal to the start of the command at each run.", { default: false })
+		.parse();
 	const [command, ...files] = args;
 	let strategy: ShutdownStrategy = new WaitStrategy();
 	if (options.soft) strategy = new SoftStrategy();
 	if (options.hard) strategy = new HardStrategy();
 	if (options.wait) strategy = new WaitStrategy();
 	const extensions = options.extensions?.split(",");
-	const do_clear = options.clear ?? false;
-	return { command, files, strategy, extensions, do_clear };
+	const do_clear = options.clear;
+	const go_up = options.up;
+	return { command, files, strategy, extensions, do_clear, go_up };
 }
 
 class Watcher {
@@ -58,6 +61,7 @@ class Runner {
 		private command: string,
 		private strategy: ShutdownStrategy,
 		private do_clear: boolean,
+		private go_up: boolean,
 	) {}
 
 	public async spin(channel: Channel<Event>) {
@@ -77,6 +81,8 @@ class Runner {
 	private launch() {
 		const args = ["-c", this.command];
 		log("running", this.command);
+		if (this.go_up) this.save_cursor();
+		console.log();
 		const process = new Deno.Command("sh", { args }).spawn();
 		process.status.then(this.on_end());
 		return process;
@@ -102,9 +108,18 @@ class Runner {
 			const end_ms = Date.now();
 			const time_ms = end_ms - start_ms;
 			const secs = time_ms / 1000;
+			if (this.go_up) this.restore_cursor();
 			log("terminated", `${secs} s`);
 		};
 	}
+
+	private save_cursor() {
+		console.log("\x1bs");
+	}
+
+	private restore_cursor() {
+		console.log("\x1b[u");
+	}
 }
 
 interface ShutdownStrategy {
@@ -166,7 +181,9 @@ function catch_<T, R, Cs extends Catching<any, R>[]>(op: () => T, ...catchings:
 		for (const [kind, strategy] of catchings) {
 			if (!(exception instanceof kind)) continue;
 			if (strategy === "ignore") return;
-			return strategy(exception);
+			// trust
+			// deno-lint-ignore no-explicit-any
+			return strategy(exception as any);
 		}
 	}
 }