London|25-SDC-NOV| FATMA DEGIRMENCI | Sprint 3|IMPLEMENT_SHELL_TOOLS

implement-shell-tools/cat/cat.js

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("cat command")
+  .description("create cat command")
+  .option("-n", "Number all lines")
+  .option("-b", "Number non-empty lines")
+  .argument("<paths...>", "File paths");
+
+program.parse();
+const paths = program.args;
+const number = program.opts().n;
+const nonEmptyLine = program.opts().b;
+
+let lineNumber = 1;
+
+for (const path of paths) {
+  try {
+    const read = await fs.readFile(path, "utf-8");
+    const lines = read.split("\n");
+    for (let i of lines) {
+      if (number) {
+        console.log(`${String(lineNumber).padStart(6, " ")} ${i}`);
+        lineNumber++;
+      } else if (nonEmptyLine) {
+        if (i.trim() !== "") {
+          console.log(`${String(lineNumber).padStart(6, " ")} ${i}`);
+          lineNumber++;
+        } else {
+          console.log(i);
+        }
+      } else {
+        console.log(i);
+      }
+    }
+  } catch (err) {
+    console.error(`File could not read: ${path}`);
+  }
+}

implement-shell-tools/ls/ls.js

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("ls command")
+  .description("create ls command")
+  .option("-1", "One entry per line")
+  .option("-a", "Show all files including hidden")
+  .argument("[paths...]", "File paths");
+
+program.parse();
+
+const opts = program.opts();
+const paths = program.args.length > 0 ? program.args : ["."];
+const onePerLine = opts["1"];
+const showAll = opts.a;
+
+for (const targetPath of paths) {
+  try {
+    let files = await fs.readdir(targetPath);
+
+    if (!showAll) {
+      files = files.filter((f) => !f.startsWith("."));
+    }
+
+
+    if (paths.length > 1) {
+      console.log(`${targetPath}:`);
+    }
+
+    if (onePerLine) {
+      for (const f of files) console.log(f);
+    } else {
+      console.log(files.join("  "));
+    }
+
+    if (paths.length > 1) {
+      console.log(); 
+    }
+  } catch (err) {
+    console.error(`ls: cannot access '${targetPath}': ${err.message}`);
+  }
+}

implement-shell-tools/package.json

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+{
+  "name": "implement-shell-tools",
+  "version": "1.0.0",
+  "description": "Your task is to re-implement shell tools you have used.",
+  "main": "index.js",
+  "type": "module",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "commander": "^14.0.2"
+  }
+}

implement-shell-tools/wc/wc.js

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+
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .option("-l", "Print only the line count")
+  .option("-w", "Print only the word count")
+  .option("-c", "Print only the byte count")
+  .argument("<paths...>", "One or more file paths");
+
+program.parse();
+
+const opts = program.opts();
+const paths = program.args;
+
+async function wcFile(path) {
+  const content = await fs.readFile(path, "utf8");
+
+  const lines = content.split("\n").length;
+  const words = content.trim().split(/\s+/).filter(Boolean).length;
+  const bytes = Buffer.byteLength(content, "utf8");
+
+  return { lines, words, bytes };
+}
+
+function formatOutput(counts, filename, opts) {
+  if (opts.l) return `${counts.lines} ${filename}`;
+  if (opts.w) return `${counts.words} ${filename}`;
+  if (opts.c) return `${counts.bytes} ${filename}`;
+
+  return `${counts.lines} ${counts.words} ${counts.bytes} ${filename}`;
+}
+
+async function main() {
+  let total = { lines: 0, words: 0, bytes: 0 };
+  let multipleFiles = paths.length > 1;
+
+  for (const path of paths) {
+    const counts = await wcFile(path);
+
+    total.lines += counts.lines;
+    total.words += counts.words;
+    total.bytes += counts.bytes;
+
+    console.log(formatOutput(counts, path, opts));
+  }
+
+  if (multipleFiles) {
+    console.log(formatOutput(total, "total", opts));
+  }
+}
+
+main();