West Midlands | SDC-July | Gabriel Deng | Sprint 3 | Implement shell tools

.vscode/launch.json

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+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Launch Program",
+      "skipFiles": [
+        "<node_internals>/**"
+      ],
+      "program": "${workspaceFolder}/implement-shell-tools/wc/wc.mjs"
+    }
+  ]
+}

implement-shell-tools/cat/cat.mjs

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import process from "node:process";
+
+
+program
+  .name("Display the contents of a file")
+  .description("Should effectively display the contents of a file as cat does even with extra flags")
+  .option("-n", "The character numbers all the lines of output.")
+  .option("-b", "The character numbers only the nonempty lines of the output")
+  .argument("<files...>");
+
+program.parse();
+
+const files = program.args;
+const options = program.opts();
+
+if (files.length === 0) {
+  console.error(`Expected at least 1 argument (a path) to be passed but got ${files.length}.`);
+  process.exit(1);
+}
+
+let lineNum = 1;
+
+for (const file of files) {
+  const content = await fs.readFile(file, "utf-8");
+  const lines = content.split("\n");
+
+  for (const line of lines) {
+    if (options.b) {
+      if (line.trim() !== "") {
+        console.log(`${(lineNum).toString().padStart(6)}  ${line}`);
+        lineNum++;
+      }
+      else {
+        console.log(line);
+      }
+    }
+    else if (options.n) {
+      console.log(`${(lineNum).toString().padStart(6)}  ${line}`);
+      lineNum++;
+    }
+    else {
+      console.log(line);
+    }
+  }
+
+}

implement-shell-tools/cat/package.json

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+{
+  "type": "module",
+  "dependencies": {
+    "commander": "^14.0.0"
+  }
+}

implement-shell-tools/ls/ls.mjs

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import process from "node:process";
+
+program
+  .name("ls")
+  .description("This is a program to display the childern of a directory.")
+  .option("-1, --one", "This is to list all the children of a directory, one per line.")
+  .option("-a", "The flag to list the children of a directory one per line in long format.")
+  .argument("<filepath>")
+
+program.parse(process.argv);
+
+const opts = program.opts();
+const args = program.args;
+
+if (args.length != 1) {
+  console.error(`Expected exactly 1 argument (a path) to be passed but got ${args.length}.`);
+  process.exit(1);
+}
+
+const content = await fs.readdir(args[0], "utf-8");
+
+const results = content.join(' ')
+// const regex = '/\n/'
+
+const filtered = content.filter((word) => word.charAt(0) !== '.')
+
+if (opts.one) {
+  console.log(filtered.join('\n'))
+}
+else if (opts.a) {
+  console.log(content.join(' '));
+}
+else {
+  console.log(filtered.join(' '))
+}
+

implement-shell-tools/ls/package.json

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

implement-shell-tools/wc/package.json

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

implement-shell-tools/wc/wc.mjs

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import process from "node:process";
+
+program
+  .name("wc")
+  .description("A program to implement word, character and line counter.")
+  .option("-l", "Counts the lines in a file")
+  .option("-w", "Counts the words in a file")
+  .option("-c", "Counts the characters in a file")
+  .argument("<filepath...>");
+
+program.parse(process.argv);
+
+const opts = program.opts();
+const args = program.args;
+
+if (args.length === 0) {
+  console.error(`Expected at least one argument but received ${args.length}`);
+  process.exit(1);
+}
+
+let totalLines = 0;
+let totalWords = 0;
+let totalChars = 0;
+
+for (const file of args) {
+  const content = await fs.readFile(file, "utf-8");
+  const linesArr = content.split('\n');
+  const lines = linesArr[linesArr.length - 1] === '' ? linesArr.length - 1 : linesArr.length;
+  const words = content.split(/\s+/).filter(Boolean).length;
+  const chars = content.length;
+
+  totalLines += lines;
+  totalWords += words;
+  totalChars += chars;
+
+  let output = '';
+  if (opts.l) output += `${lines} `;
+  if (opts.w) output += `${words} `;
+  if (opts.c) output += `${chars} `;
+  if (!opts.l && !opts.w && !opts.c) output += `${lines} ${words} ${chars} `;
+  output += file;
+  console.log(output);
+}
+
+if (args.length > 1) {
+  let totalOutput = '';
+  if (opts.l) totalOutput += `${totalLines} `;
+  if (opts.w) totalOutput += `${totalWords} `;
+  if (opts.c) totalOutput += `${totalChars} `;
+  if (!opts.l && !opts.w && !opts.c) totalOutput += `${totalLines} ${totalWords} ${totalChars} `;
+  totalOutput += 'total';
+  console.log(totalOutput);
+}