implemented cat, ls, wc with java script

Author: HilolaRustam

implement-shell-tools/cat/my-cat.js

@@ -0,0 +1,41 @@
+#!/usr/bin/env node
+
+const fs = require("fs");
+
+const args = process.argv.slice(2);
+
+let numberLines = false;
+let numberNonEmpty = false;
+
+if (args[0] === "-n") {
+  numberLines = true;
+  args.shift();
+} else if (args[0] === "-b") {
+  numberNonEmpty = true;
+  args.shift();
+}
+let count = 1;
+
+args.forEach((file) => {
+  const content = fs.readFileSync(file, "utf-8");
+  const lines = content.split(/\r?\n/);
+  
+
+  if (numberLines){ 
+    lines.forEach((line) => {
+      console.log(`${count} ${line}`);
+      count++;
+    });
+  } else if (numberNonEmpty){
+    lines.forEach((line) => {
+    if (line !== "") {
+      console.log(`${count} ${line}`);
+      count++;
+    } else {
+      console.log("");
+    }
+  });
+} else {
+console.log(content);
+  }
+});

implement-shell-tools/ls/my-ls.js

@@ -0,0 +1,41 @@
+#!/usr/bin/env node 
+
+const fs = require("node:fs");
+const path = require("node:path");
+
+function parseArgs(args) {
+  let showAll = false;
+  let targetDir = ".";
+
+  for (const arg of args) {
+    if (arg === "-a") {
+      showAll = true;
+    } else if (!arg.startsWith("-")) {
+      targetDir = arg;
+    }
+  }
+
+  return { showAll, targetDir };
+}
+
+function listDirectory(dirPath, showAll) {
+  let files = fs.readdirSync(dirPath);
+
+  if (!showAll) {
+    files = files.filter(file => !file.startsWith("."));
+  }
+
+  return files.sort();
+}
+
+function main() {
+  const args = process.argv.slice(2);
+  const { showAll, targetDir } = parseArgs(args);
+
+  const files = listDirectory(targetDir, showAll);
+  console.log(files.join("\n"));
+}
+
+main();
+
+

implement-shell-tools/wc/my-wc.js

@@ -0,0 +1,67 @@
+#!/usr/bin/env node
+
+const fs = require("node:fs");
+
+function countFile(filePath) {
+  const content = fs.readFileSync(filePath, "utf8");
+
+  const lines = content.split("\n").length - 1;
+  const words = content.trim() ? content.trim().split(/\s+/).length : 0;
+  const chars = Buffer.byteLength(content, "utf8");
+
+  return { lines, words, chars };
+}
+
+function main() {
+  const args = process.argv.slice(2);
+
+  let flag = null;
+  let files = [];
+
+  for (const arg of args) {
+    if (arg === "-l" || arg === "-w" || arg === "-c") {
+      flag = arg;
+    } else {
+      files.push(arg);
+    }
+  }
+
+  let totalLines = 0;
+  let totalWords = 0;
+  let totalChars = 0;
+
+  for (const file of files) {
+    const { lines, words, chars } = countFile(file);
+
+    totalLines += lines;
+    totalWords += words;
+    totalChars += chars;
+
+    if (flag === "-l") {
+      console.log(`${lines} ${file}`);
+    } else if (flag === "-w") {
+      console.log(`${words} ${file}`);
+    } else if (flag === "-c") {
+      console.log(`${chars} ${file}`);
+    } else {
+      console.log(`${lines} ${words} ${chars} ${file}`);
+    }
+  }
+
+  if (files.length > 1) {
+    if (flag === "-l") {
+      console.log(`${totalLines} total`);
+    } else if (flag === "-w") {
+      console.log(`${totalWords} total`);
+    } else if (flag === "-c") {
+      console.log(`${totalChars} total`);
+    } else {
+      console.log(`${totalLines} ${totalWords} ${totalChars} total`);
+    }
+  }
+}
+
+main();
+
+
+