London | 25-SDC-July | Aung Ye Kyaw | sprint 3|Implementation shell tools exercise

implement-shell-tools/cat/sample-files/cat.js

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+
+program
+  .name("cat")
+  .description("Prints file content with optional line numbers")
+  .argument("<file>", "file to read")
+  .option("-n, --number", "number all lines")
+  .option("-b, --number-nonblank", "number non-blank lines only")
+  .parse();
+
+const options = program.opts();
+const filePath = program.args[0];
+
+try {
+  const content = await fs.readFile(filePath, "utf-8");
+  const lines = content.split("\n");
+
+  lines.forEach((line, index) => {
+    const lineNumber = index + 1;
+    if (options.number) {
+
+      console.log(`${lineNumber.toString().padStart(4)}  ${line}`);
+    } else if (options.numberNonblank) {
+
+      if (line.trim() === "") {
+        console.log("     " + line);
+      } else {
+        console.log(`${lineNumber.toString().padStart(4)}  ${line}`);
+      }
+    } else {
+
+      console.log(line);
+    }
+  });
+} catch (err) {
+  console.error(`Error reading file "${filePath}":`, err.message);
+  process.exit(1);
+}
+
+
+

implement-shell-tools/ls/ls.js

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+import {program} from "commander";
+import {promises as fs} from "node:fs";
+
+program
+ .name ("ls")
+ .description("List the file directory")
+ .option("-1","List one file per line")
+ .option("-a","Include hidden file")
+ .argument("[dir]", "Directory to list",".")
+ .parse();
+
+ const options = program.opts();
+const dir = program.args[0] || ".";
+
+try {
+  const items = await fs.readdir(dir, { withFileTypes: true });
+
+  let fileNames = items.map(item => item.name);
+
+  // Filter out hidden files unless -a
+  if (!options.a) {
+    fileNames = fileNames.filter(name => !name.startsWith("."));
+  }
+
+  // Print output
+  if (options["1"]) {
+    // One file per line
+    fileNames.forEach(name => console.log(name));
+  } else {
+    // Default: space-separated (like regular `ls`)
+    console.log(fileNames.join("  "));
+  }
+} catch (err) {
+  console.error(`Error reading directory "${dir}":`, err.message);
+  process.exit(1);
+}
+

implement-shell-tools/wc/wc.js

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("wc")
+  .description("Custom wc CLI - count lines, words, bytes")
+  .argument("<file>", "File to process")
+  .option("-l", "Print the number of lines")
+  .option("-w", "Print the number of words")
+  .option("-c", "Print the number of bytes")
+  .parse();
+
+const options = program.opts();
+const filePath = program.args[0];
+
+try {
+  const data = await fs.readFile(filePath,"utf-8");
+
+
+
+  const lineCount = data.split("\n").length;
+  const wordCount = data.trim().split(/\s+/).length;
+  const byteCount = data.length;
+
+  const showAll = !options.l && !options.w && !options.c;
+
+
+  const output = [];
+  if (options.l || showAll) output.push(lineCount.toString().padStart(8));
+  if (options.w || showAll) output.push(wordCount.toString().padStart(8));
+  if (options.c || showAll) output.push(byteCount.toString().padStart(8));
+  output.push(filePath);
+
+  console.log(output.join(" "));
+} catch (err) {
+  console.error(`Error reading file "${filePath}":`, err.message);
+  process.exit(1);
+}

package.json

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+{
+  "dependencies": {
+    "commander": "^14.0.0"
+  }
+}