Node nodejs fundamentals

.gitignore

@@ -3,10 +3,6 @@ node_modules/
 *.log
 npm-debug.log*
 .env
-workspace/
 workspace_restored/
 snapshot.json
-data.json
-checksums.json
-source.txt
 chunk_*.txt

Readme.md

@@ -1,4 +1,4 @@
-# Node.js Fundamentals
+# Node.js Fundamentals by Vladimir Tugutov (https://github.com/vladimirtugutov)
 
 ## Description
 
@@ -62,6 +62,33 @@ Snapshot format reminder:
 - `npm run cli:interactive` - Interactive command-line interface
 - `npm run cli:progress` - Display progress bar
 
+To run with color use:
+
+#### With color - IMPORTANT: use quotes or escaping!
+node src/cli/progress.js --color "#00ff00"    # Green
+node src/cli/progress.js --color '#0000ff'    # Blue  
+node src/cli/progress.js --color "#ff0000"    # Red
+node src/cli/progress.js --color "#ffff00"    # Yellow
+
+#### Full customization
+node src/cli/progress.js \
+  --duration 3000 \
+  --interval 50 \
+  --length 50 \
+  --color "#00ff00"
+
+#### Windows CMD (quotes not required)
+node src\cli\progress.js --color #00ff00
+
+#### npm Scripts:
+npm run cli:progress -- --color "#00ff00"
+
+#### DOESN'T WORK: #00ff00 becomes a comment
+node src/cli/progress.js --color #00ff00
+
+#### WORKS: quotes protect from shell
+node src/cli/progress.js --color "#00ff00"
+
 ### Modules (src/modules)
 
 - `npm run modules:dynamic` - Dynamic plugin loading

data.json

@@ -0,0 +1 @@
+[5, 1, 9, 3, 7, 2, 8, 4, 6]

source.txt

@@ -0,0 +1,21 @@
+line 1
+line 2
+line 3
+line 4
+line 5
+line 6
+line 7
+line 8
+line 9
+line 10
+line 11
+line 12
+line 13
+line 14
+line 15
+line 16
+line 17
+line 18
+line 19
+line 20
+line 21

src/checksums.json

@@ -0,0 +1,4 @@
+{
+  "file1.txt": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
+  "file2.txt": "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
+}

src/cli/interactive.js

@@ -1,8 +1,46 @@
+import readline from 'node:readline';
+import { stdin as input, stdout as output } from 'node:process';
+
 const interactive = () => {
-  // Write your code here
-  // Use readline module for interactive CLI
-  // Support commands: uptime, cwd, date, exit
-  // Handle Ctrl+C and unknown commands
+  const rl = readline.createInterface({ input, output, prompt: '> ' });
+
+  const handleCommand = (line) => {
+    const cmd = line.trim();
+
+    switch (cmd) {
+      case 'uptime':
+        output.write(`Uptime: ${process.uptime().toFixed(2)}s\n`);
+        break;
+      case 'cwd':
+        output.write(`${process.cwd()}\n`);
+        break;
+      case 'date':
+        output.write(`${new Date().toISOString()}\n`);
+        break;
+      case 'exit':
+        output.write('Goodbye!\n');
+        rl.close();
+        return;
+      default:
+        output.write('Unknown command\n');
+        break;
+    }
+
+    rl.prompt();
+  };
+
+  rl.on('line', handleCommand);
+
+  rl.on('SIGINT', () => {
+    output.write('Goodbye!\n');
+    rl.close();
+  });
+
+  rl.on('close', () => {
+    process.exit(0);
+  });
+
+  rl.prompt();
 };
 
 interactive();

src/cli/progress.js

@@ -1,8 +1,85 @@
+import { argv, stdout } from 'node:process';
+
+const parseArgs = () => {
+  const args = argv.slice(2);
+  const options = {};
+
+  for (let i = 0; i < args.length; i += 2) {
+    const key = args[i];
+    const value = args[i + 1];
+    if (!value && key === '--color') {
+      stdout.write(
+        'Hint: use quotes or escaping for color, e.g. --color "#00ff00". If you use npm run script add "-- -- color ..."\n'
+      );
+    }
+    if (!value) continue;
+
+    switch (key) {
+      case '--duration':
+        options.duration = Number(value);
+        break;
+      case '--interval':
+        options.interval = Number(value);
+        break;
+      case '--length':
+        options.length = Number(value);
+        break;
+      case '--color':
+        options.color = value;
+        break;
+      default:
+        break;
+    }
+  }
+
+  return options;
+};
+
+const isValidHexColor = (value) => /^#([0-9a-fA-F]{6})$/.test(value);
+
 const progress = () => {
-  // Write your code here
-  // Simulate progress bar from 0% to 100% over ~5 seconds
-  // Update in place using \r every 100ms
-  // Format: [████████████████████          ] 67%
+  const {
+    duration = 5000,
+    interval = 100,
+    length = 30,
+    color,
+  } = parseArgs();
+
+  const totalSteps = Math.max(1, Math.floor(duration / interval));
+  const useColor = typeof color === 'string' && isValidHexColor(color);
+
+  let currentStep = 0;
+
+  const timer = setInterval(() => {
+    currentStep += 1;
+    const fraction = Math.min(1, currentStep / totalSteps);
+    const percent = Math.round(fraction * 100);
+
+    const filledLength = Math.round(length * fraction);
+    const emptyLength = length - filledLength;
+
+    const filled = '█'.repeat(filledLength);
+    const empty = ' '.repeat(emptyLength);
+
+    let bar = `[${filled}${empty}] ${percent}%`;
+
+    if (useColor && filledLength > 0) {
+      const r = parseInt(color.slice(1, 3), 16);
+      const g = parseInt(color.slice(3, 5), 16);
+      const b = parseInt(color.slice(5, 7), 16);
+      const colorPrefix = `\x1b[38;2;${r};${g};${b}m`;
+      const reset = '\x1b[0m';
+      const coloredFilled = `${colorPrefix}${filled}${reset}`;
+      bar = `[${coloredFilled}${empty}] ${percent}%`;
+    }
+
+    stdout.write(`\r${bar}`);
+
+    if (currentStep >= totalSteps) {
+      clearInterval(timer);
+      stdout.write('\nDone!\n');
+    }
+  }, interval);
 };
 
 progress();

src/cp/execCommand.js

@@ -1,10 +1,37 @@
+import { spawn } from 'node:child_process';
+import { argv } from 'node:process';
+
 const execCommand = () => {
-  // Write your code here
-  // Take command from CLI argument
-  // Spawn child process
-  // Pipe child stdout/stderr to parent stdout/stderr
-  // Pass environment variables
-  // Exit with same code as child
+  const args = argv.slice(2);
+
+  if (args.length === 0) {
+    console.error('Usage: node execCommand.js "command [args...]"');
+    process.exit(1);
+  }
+
+  const command = args.join(' ');
+
+  const parts = command.split(' ');
+  const cmd = parts[0];
+  const cmdArgs = parts.slice(1);
+
+  const child = spawn(cmd, cmdArgs, {
+    stdio: ['inherit', 'pipe', 'pipe'],
+    env: { ...process.env }
+  });
+
+  child.stdout.pipe(process.stdout);
+
+  child.stderr.pipe(process.stderr);
+
+  child.on('exit', (code) => {
+    process.exit(code);
+  });
+
+  child.on('error', (error) => {
+    console.error('Spawn error:', error.message);
+    process.exit(1);
+  });
 };
 
 execCommand();

src/files/file1.txt

@@ -0,0 +1 @@
+test

src/files/file2.txt

@@ -0,0 +1 @@
+hello

src/fs/findByExt.js

@@ -1,7 +1,57 @@
+import { readdir, stat } from 'fs/promises';
+import { dirname, join, extname } from 'path';
+import { fileURLToPath } from 'url';
+import { argv } from 'node:process';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+const parseExtArg = () => {
+  const args = argv.slice(2);
+  for (let i = 0; i < args.length; i++) {
+    if (args[i] === '--ext' && args[i + 1]) {
+      return args[i + 1].startsWith('.') ? args[i + 1] : `.${args[i + 1]}`;
+    }
+  }
+  return '.txt'; // Default
+};
+
+const findFilesByExtension = async (dir, ext, relativeBase) => {
+  const entries = await readdir(dir, { withFileTypes: true });
+  const files = [];
+
+  for (const entry of entries) {
+    const fullPath = join(dir, entry.name);
+    const relPath = join(relativeBase, entry.name);
+
+    if (entry.isDirectory()) {
+      const subFiles = await findFilesByExtension(fullPath, ext, relPath);
+      files.push(...subFiles);
+    } else if (extname(entry.name) === ext) {
+      files.push(relPath);
+    }
+  }
+
+  return files;
+};
+
 const findByExt = async () => {
-  // Write your code here
-  // Recursively find all files with specific extension
-  // Parse --ext CLI argument (default: .txt)
+  const ext = parseExtArg();
+  const workspacePath = join(__dirname, '..', 'workspace');
+
+  try {
+    const files = await findFilesByExtension(workspacePath, ext, '');
+    const sortedFiles = files.sort();
+
+    for (const file of sortedFiles) {
+      console.log(file);
+    }
+  } catch (error) {
+    if (error.code === 'ENOENT') {
+      throw new Error('FS operation failed');
+    }
+    throw error;
+  }
 };
 
 await findByExt();