London | 26-SDC-MAR | Craig D'Silva | Sprint 3 | Implement Shell Tools

implement-shell-tools/cat/cat.js

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+import { program } from "commander";
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+let showNumber = false;
+
+program
+  .name("cat")
+  .description("Prints the output of a file to the console")
+  .option("-n, --number", "Displays the lines along with their number")
+  .argument("<path>", "The file path")
+  .allowExcessArguments();
+program.parse();
+
+const argv = program.args;
+if (argv.length < 1) {
+  console.error(
+    `Expected exactly 1 or more arguments (paths) to be passed but got ${argv.length}.`,
+  );
+  process.exit(1);
+}
+
+showNumber = program.opts().number;
+
+const stringArr = [];
+for (const path of argv) {
+  stringArr.push(await fs.readFile(path, "utf-8"));
+}
+
+const flatArr = stringArr.flatMap((l) =>
+  l
+    .split("\n")
+    .map((l, i, a) => (i < a.length - 1 ? l + "\n" : l))
+    .filter((l) => l !== ""),
+);
+
+if (!showNumber) console.log(flatArr.join(""));
+else console.log(flatArr.map((l, i) => `${i + 1} ${l}`).join(""));

implement-shell-tools/cat/package.json

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+{
+  "name": "cat",
+  "version": "1.0.0",
+  "description": "You should already be familiar with the `cat` command line tool.",
+  "license": "ISC",
+  "author": "",
+  "type": "module",
+  "main": "cat.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "dependencies": {
+    "commander": "^14.0.3"
+  }
+}

implement-shell-tools/ls/ls.js

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+import { program } from "commander";
+import process from "node:process";
+import fs from "node:fs";
+
+let vertical = false;
+let showHidden = false;
+
+program
+  .name("list-directory-contents")
+  .description("Shows all files and folders in a directory")
+  .option("-1", "List one file/directory per line")
+  .option("-a, --all", "Show hidden files")
+  .argument("[path]", "Path of the directory to list (defaults to .)");
+
+program.parse();
+
+const argv = program.args;
+
+vertical = program.opts()[1];
+showHidden = program.opts().all;
+
+const folderPath = argv[0] || ".";
+
+const contents = fs.readdirSync(folderPath);
+
+const filtered = contents.filter((f) => f[0] !== ".");
+
+const dirArr = !showHidden ? filtered : contents;
+
+if (!vertical) {
+  console.log(dirArr.join("  "));
+} else {
+  for (const content of dirArr) {
+    console.log(content);
+  }
+}

implement-shell-tools/ls/package.json

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+{
+  "name": "ls",
+  "version": "1.0.0",
+  "description": "You should already be familiar with the `ls` command line tool.",
+  "main": "ls.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "type": "module",
+  "dependencies": {
+    "commander": "^14.0.3"
+  }
+}

implement-shell-tools/wc/package.json

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+{
+  "name": "wc",
+  "version": "1.0.0",
+  "description": "You should already be familiar with the `wc` command line tool.",
+  "main": "wc.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "type": "module",
+  "dependencies": {
+    "commander": "^14.0.3"
+  }
+}

implement-shell-tools/wc/wc.js

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+import { program } from "commander";
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+let showLineCount = true;
+let showWordCount = true;
+let showByteCount = true;
+
+program
+  .name("wc")
+  .description(
+    "Print the number of lines, word and bytes for each file and a total if there are multiple files",
+  )
+  .option("-l, --lines", "Print the number of lines")
+  .option("-w, --words", "Print the number of words")
+  .option("-c, --bytes", "Print the number of bytes")
+  .argument("<path>", "The file path")
+  .allowExcessArguments();
+program.parse();
+
+const argv = program.args;
+
+if (Object.keys(program.opts()).length >= 1) {
+  showLineCount = program.opts().lines;
+  showWordCount = program.opts().words;
+  showByteCount = program.opts().bytes;
+}
+
+const stringArr = [];
+for (const path of argv) {
+  stringArr.push(await fs.readFile(path, "utf-8"));
+}
+
+let lines = 0;
+let words = 0;
+let bytes = 0;
+
+const infoArr = [];
+for (let i = 0; i < stringArr.length; i++) {
+  const arr = [];
+  const line = stringArr[i].split("\n").length;
+  const wc = stringArr[i].split(" ").flatMap((l) =>
+    l
+      .split("\n")
+      .map((l, i, a) => (i < a.length - 1 ? l + "\n" : l))
+      .filter((l) => l.trim() !== ""),
+  ).length;
+  const lineByte = new Blob([stringArr[i]]).size;
+  if (showLineCount) {
+    arr.push(line - 1);
+    lines += line - 1;
+  }
+  if (showWordCount) {
+    arr.push(wc);
+    words += wc;
+  }
+  if (showByteCount) {
+    arr.push(lineByte);
+    bytes += lineByte;
+  }
+  arr.push(argv[i]);
+  infoArr.push(arr.join(" "));
+}
+
+if (infoArr.length > 1) {
+  const totalArr = ["total"];
+  if (showByteCount) totalArr.unshift(bytes);
+  if (showWordCount) totalArr.unshift(words);
+  if (showLineCount) totalArr.unshift(lines);
+  infoArr.push(totalArr.join(" "));
+}
+console.log(infoArr.join("\n"));