Glasgow | 25-SDC-July | Sheetal Kharab | Sprint 3 | Implement shell tools

implement-shell-tools/cat/cat.js

@@ -0,0 +1,56 @@
+import { program } from "commander";
+import process from "node:process";
+import { promises as fs } from "node:fs";
+import glob from "glob";
+
+program
+  .name("cat")
+  .description("print the content of file")
+  .option("-n, --line-numbers", "Number the output lines, starting at 1")
+  .option(
+    "-b, --number-nonblank",
+    "Number non-empty output lines, overrides -n"
+  )
+  .argument("<paths...>", "The file path(s) to process"); // to support multiple file
+program.parse();
+
+const argv = program.args.flatMap((path) => glob.sync(path));
+
+const options = program.opts();
+if (argv.length === 0) {
+  console.error(`No file paths provided`); // to support more files
+  process.exit(1);
+}
+
+let lineCounter = 1;
+function printLine(line, number = false) {
+  if (number && line.trim() !== "") {
+    const lineNumber = String(lineCounter++).padStart(6, " ");
+    console.log(`${lineNumber}\t${line}`);
+  } else {
+    console.log(line);
+  }
+}
+// Helper function to print totals for multiple files
+function printTotal(total, label = "total") {
+  console.log(`${total} ${label}`);
+}
+for (const path of argv) {
+  try {
+    const content = await fs.readFile(path, "utf-8");
+    const lines = content.split(/\r?\n/);
+    if (lines.length && lines[lines.length - 1] === "") {
+      // Remove trailing empty line if it's just from the final newline
+      lines.pop();
+    }
+    // Determine if we need to number lines
+    const numberLines = options.numberNonblank || options.lineNumbers;
+
+    lines.forEach((line) => printLine(line, numberLines));
+
+    // Add a newline if the file didn't end with one
+    if (!content.endsWith("\n")) process.stdout.write("\n");
+  } catch (err) {
+    console.error(`cat: ${path}: ${err.message}`);
+  }
+}

implement-shell-tools/ls/ls.js

@@ -0,0 +1,35 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("ls")
+  .description("Displays files in a directory")
+  .option("-1, --one", "Display each file on a new line")// for listing one file per line
+  .option("-a, --all", "Include hidden files")
+  .argument("[filepath]", "Directory to list files from (default: current)")
+
+await program.parseAsync();  
+
+const opts = program.opts();
+const args = program.args;
+
+const path = args[0] || "."; //Use current directory if no path provided
+let files ;
+try {
+    files = await fs.readdir(path);
+}catch (err) {
+    console.error(`ls: cannot access '${path}': ${err.message}`);
+    process.exit(1);
+
+}
+
+if (!opts.all) {
+  files = files.filter(file => !file.startsWith("."));// if path not provided use current directory
+}
+
+if (opts.one) {
+  files.forEach(file => console.log(file));
+} else {
+  console.log(files.join(" "));
+}
+

implement-shell-tools/package.json

@@ -0,0 +1,7 @@
+{
+  "type": "module",
+  "dependencies": {
+    "commander": "^14.0.0",
+    "glob": "^8.1.0"
+  }
+}

implement-shell-tools/wc/wc.js

@@ -0,0 +1,61 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import pkg from "glob";
+const { glob } = pkg;
+
+program
+  .name("wc")
+  .description("Count lines, words, and bytes in files")
+  .option("-l, --lines", "Only print line counts")
+  .option("-w, --words", "Only print word counts")
+  .option("-c, --bytes", "Only print byte counts")
+  .argument("<files...>", "One or more files to process");
+await program.parseAsync();
+
+const files = program.args.flatMap((path) => glob.sync(path));
+const options = program.opts();
+
+function countContent(content) {
+  const lines = (content.match(/\n/g) || []).length;
+  const words = content.trim().split(/\s+/).filter(Boolean).length;
+  const bytes = Buffer.byteLength(content, "utf-8");
+  return { lines, words, bytes };
+}
+// Helper to print counts based on options
+function printCounts({ lines, words, bytes }, label) {
+  if (options.lines) {
+    console.log(`${lines} ${label}`);
+  } else if (options.words) {
+    console.log(`${words} ${label}`);
+  } else if (options.bytes) {
+    console.log(`${bytes} ${label}`);
+  } else {
+    console.log(`${lines} ${words} ${bytes} ${label}`);
+  }
+}
+
+let totalLines = 0;
+let totalWords = 0;
+let totalBytes = 0;
+
+for (const file of files) {
+  try {
+    const content = await fs.readFile(file, "utf-8");
+    const counts = countContent(content);
+
+    printCounts(counts, file);
+
+    totalLines += counts.lines;
+    totalWords += counts.words;
+    totalBytes += counts.bytes;
+  } catch (err) {
+    console.error(`wc: ${file}: ${err.message}`);
+  }
+}
+
+if (files.length > 1) {
+  printCounts(
+    { lines: totalLines, words: totalWords, bytes: totalBytes },
+    "total"
+  );
+}