Implemented cat,ls, and wc commant line tool. And also created an empty txt file to check my output for wc.mjs

Author: MansoorM11

implement-shell-tools/cat/cat.mjs

@@ -0,0 +1,32 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+let args = process.argv.slice(2);
+const flags = args.filter((arg) => arg.startsWith("-"));
+const filePaths = args.filter((args) => !args.startsWith("-"));
+let lineNumber = 1;
+
+for (const filePath of filePaths) {
+  const content = await fs.readFile(filePath, "utf-8");
+
+  if (flags.length == 0) {
+    process.stdout.write(content);
+    continue;
+  }
+
+  const lines = content.split("\n");
+
+  for (const line of lines) {
+    if (flags.includes("-b")) {
+      if (line === "") {
+        console.log();
+      } else {
+        console.log(`${lineNumber}\t${line}`);
+        lineNumber++;
+      }
+    } else if (flags.includes("-n")) {
+      console.log(`${lineNumber}\t${line}`);
+      lineNumber++;
+    }
+  }
+}

implement-shell-tools/ls/ls.mjs

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+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const args = process.argv.slice(2);
+const flags = args.filter((arg) => arg.startsWith("-"));
+const path = args.filter((arg) => !arg.startsWith("-"));
+let targetDir = path[0] || ".";
+let files = await fs.readdir(targetDir);
+
+if (flags.includes("-a")) {
+  files.unshift(".", "..");
+} else {
+  files = files.filter((fileName) => !fileName.startsWith("."));
+}
+
+if (flags.includes("-1")) {
+  for (const file of files) {
+    console.log(file);
+  }
+} else {
+  console.log(files.join(" "));
+}

implement-shell-tools/wc/sample-files/4.txt

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+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+let filePaths = [];
+let flag = null;
+let numberOfWords;
+
+if (process.argv[2].startsWith("-")) {
+  flag = process.argv[2];
+  filePaths = process.argv.slice(3);
+} else {
+  filePaths = process.argv.slice(2);
+}
+for (const filePath of filePaths) {
+  const content = await fs.readFile(filePath, "utf-8");
+
+  if (flag === "-w") {
+    console.log(getWordCount(content));
+  } else if (flag === "-l") {
+    console.log(getLineCount(content));
+  } else if (flag === "-c") {
+    console.log(getByteCount(content), filePaths);
+  } else {
+    console.log(
+      getWordCount(content),
+      getLineCount(content),
+      getByteCount(content),
+      filePaths,
+    );
+  }
+}
+
+function getWordCount(text) {
+  const trimmed = text.trim();
+  if (trimmed.length == 0) {
+    return 0;
+  }
+  return trimmed.split(/\s+/).length;
+}
+
+function getLineCount(text) {
+  if (text.length == 0) return 0;
+  return text.split("\n").length - 1;
+}
+
+function getByteCount(text) {
+  return Buffer.byteLength(text, "utf-8");
+}