将UnityEditor的Log输出到终端

背景

使用CI/CD构建unity项目, shell脚本调用npm script拉起unity后UnityEngin.Debug.Log的输出只会展示在unity的控制台里, 那么如何将其输出到终端以便监控其构建过程呢

解决方案

1. 将要输出日志写入到log.txt文件

public static void Print(string str)
{
    using (StreamWriter logFile = new StreamWriter('log.txt', true))
        logFile.WriteLine($"[{DateTime.Now}] {str}");
    UnityEngine.Debug.Log(str);

}

2. 使用node.js监听log.txt文件并打印到终端

要注意避免文件系统多次触发change事件导致的重复打印, 另外要注意停止文件监听以便退出构建流程

代码如下

let watcher;

function unityConsoleLog() {
    const fs = require("fs");
    const readline = require("readline");
    const path = require("path");
    const filePath = path.join(__dirname, "log.txt");
    let lastKnownPosition = 0;

    // 检查文件是否存在
    if (fs.existsSync(filePath)) {
        // 文件存在，清空文件内容
        fs.writeFile(filePath, "", (err) => {
            if (err) {
                console.error("Failed to clear file:", err);
            } else {
                console.log(filePath + " File content has been cleared.");
            }
        });
    } else {
        // 文件不存在，创建文件
        fs.writeFile(filePath, "", (err) => {
            if (err) {
                console.error("Failed to create file:", err);
            } else {
                console.log(filePath + " File has been created.");
            }
        });
    }

    let processing = false;
    let lastLineHashes = new Set();

    function readNewLines(start) {
        const stream = fs.createReadStream(filePath, {
            start: start,
            encoding: "utf8",
        });

        const rl = readline.createInterface({
            input: stream,
            output: process.stdout,
            terminal: false,
        });

        processing = true;

        rl.on("line", (line) => {
            const lineHash = hashLine(line);
            if (!lastLineHashes.has(lineHash)) {
                console.log("Unity Build Log: ", line);
                lastLineHashes.add(lineHash);
            }
        });

        rl.on("close", () => {
            lastKnownPosition = fs.statSync(filePath).size;
            processing = false;
        });
    }

    function hashLine(line) {
        let hash = 0;
        for (let i = 0; i < line.length; i++) {
            let char = line.charCodeAt(i);
            hash = (hash << 5) - hash + char;
            hash |= 0;
        }
        return hash;
    }

    watcher = fs.watch(filePath, (eventType, filename) => {
        if (eventType === "change" && !processing) {
            readNewLines(lastKnownPosition);
        }
    });

    // Initialize the start of the file watching
    fs.stat(filePath, (err, stats) => {
        if (err) {
            console.error("File not found:", err);
            return;
        }
        lastKnownPosition = stats.size;
    });
}

function stopUnityConsoleLog() {
    if (watcher) {
        watcher.close();
        console.log("Stopped watching file.");
    } else {
        console.log("No watcher to stop.");
    }
}