Manchester | 25-SDC-Nov | Rahwa Haile | Sprint 3 | Implement Shell Tools

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

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+#!/usr/bin/env node
+const { program } = require("commander");
+const fs = require("fs");
+const path = require("path");
+
+function expandWildcard(pattern) {
+  const dir = path.dirname(pattern);
+  const base = path.basename(pattern);
+
+  if (!base.includes("*")) return [pattern];
+
+  let files;
+  try {
+    files = fs.readdirSync(dir);
+  } catch {
+    console.error(`cat: ${pattern}: No such directory`);
+    return [];
+  }
+
+  const regex = new RegExp("^" + base.replace(/\*/g, ".*") + "$");
+
+  return files
+    .filter((f) => regex.test(f))
+    .map((f) => path.join(dir, f));
+}
+
+function printFile(filename, options) {
+  let text;
+  try {
+    text = fs.readFileSync(filename, "utf-8");
+  } catch {
+    console.error(`cat: ${filename}: No such file`);
+    return;
+  }
+
+  const lines = text.split("\n");
+  if (lines[lines.length - 1] === "") lines.pop();
+
+  let counter = 1;
+  const paddingSize = 6;
+
+  lines.forEach((line) => {
+    const isEmpty = line.trim() === "";
+
+    const shouldNumber =
+      options.numberAll ||
+      (options.numberNonempty && !isEmpty);
+
+    if (shouldNumber) {
+      console.log(
+        `${String(counter).padStart(paddingSize)}  ${line}`
+      );
+      counter++;
+    } else {
+      console.log(line);
+    }
+  });
+}
+
+program
+  .name("mycat")
+  .description("A custom implementation of the cat command")
+  .argument("<files...>", "files or wildcard patterns")
+  .option("-n, --number-all", "number all lines")
+  .option("-b, --number-nonempty", "number non-empty lines")
+  .action((patterns, options) => {
+    let allFiles = [];
+
+    patterns.forEach((p) => {
+      allFiles = allFiles.concat(expandWildcard(p));
+    });
+
+    allFiles.forEach((file) => printFile(file, options));
+  });
+
+program.parse();

implement-shell-tools/ls/sample-files/myLs.js

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+#!/usr/bin/env node
+const { program } = require("commander");
+const fs = require("fs");
+const path = require("path");
+
+function listDirectory(dir, options) {
+  try {
+    const stats = fs.statSync(dir);
+
+    if (stats.isFile()) {
+      console.log(dir);
+      return; 
+    }
+  } catch (e) {
+    console.error(`ls: cannot access '${dir}': No such file or directory`);
+    return;
+  }
+
+  let entries;
+
+  try {
+    entries = fs.readdirSync(dir, { withFileTypes: true });
+  } catch (e) {
+    console.error(`ls: cannot access '${dir}': No such file or directory`);
+    return;
+  }
+
+  let names = entries.map(e => e.name);
+
+  if (options.all) {
+    names.unshift(".", "..");
+  } else {
+    names = names.filter(name => !name.startsWith("."));
+  }
+
+  names.sort();
+  names.forEach(name => console.log(name));
+}
+
+program
+  .name("myls")
+  .description("Custom implementation of ls")
+  .option("-1", "list one file per line (required)")
+
+  .option("-a, --all", "include hidden files")
+  .argument("[dir]", "directory to list", ".")
+  .action((dir, options) => {
+    listDirectory(dir, options);
+  });
+
+program.parse();

implement-shell-tools/wc/sample-files/myWc.js

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+#!/usr/bin/env node
+const { program } = require("commander");
+const fs = require("fs");
+const path = require("path");
+
+function expandWildcard(pattern) {
+  const dir = path.dirname(pattern);
+  const base = path.basename(pattern);
+
+  if (!base.includes("*")) return [pattern];
+
+  let files;
+  try {
+    files = fs.readdirSync(dir);
+  } catch {
+    console.error(`wc: ${pattern}: No such directory`);
+    return [];
+  }
+
+  const regex = new RegExp("^" + base.replace(/\*/g, ".*") + "$");
+  return files
+    .filter(f => regex.test(f))
+    .map(f => path.join(dir, f));
+}
+
+function countLines(text) {
+  if (text === "") return 0;
+  const matches = text.match(/\n/g) || [];
+  return text.endsWith("\n") ? matches.length : matches.length + 1;
+}
+
+function countWords(text) {
+  return text.split(/\s+/).filter(Boolean).length;
+}
+
+function countChars(text) {
+  return Buffer.byteLength(text, "utf-8");
+}
+
+function formatOutput({ lines, words, chars }, options, label) {
+  const paddingSize = 7;
+
+  const paddedLines = String(lines).padStart(paddingSize);
+  const paddedWords = String(words).padStart(paddingSize);
+  const paddedChars = String(chars).padStart(paddingSize);
+
+  const onlyLines = options.lines && !options.words && !options.chars;
+  const onlyWords = options.words && !options.lines && !options.chars;
+  const onlyChars = options.chars && !options.lines && !options.words;
+
+  if (onlyLines) return `${paddedLines} ${label}`;
+  if (onlyWords) return `${paddedWords} ${label}`;
+  if (onlyChars) return `${paddedChars} ${label}`;
+
+  return `${paddedLines} ${paddedWords} ${paddedChars} ${label}`;
+}
+
+function wcFile(filename, options) {
+  let text;
+  try {
+    text = fs.readFileSync(filename, "utf-8");
+  } catch {
+    console.error(`wc: ${filename}: No such file`);
+    return null;
+  }
+
+  const counts = {
+    lines: countLines(text),
+    words: countWords(text),
+    chars: countChars(text),
+  };
+
+  console.log(formatOutput(counts, options, filename));
+  return counts;
+}
+
+program
+  .name("mywc")
+  .description("Custom implementation of wc")
+  .option("-l, --lines", "count lines")
+  .option("-w, --words", "count words")
+  .option("-c, --chars", "count characters")
+  .argument("<files...>", "files or wildcard patterns")
+  .action((patterns, options) => {
+    let allFiles = [];
+    patterns.forEach(p => {
+      allFiles = allFiles.concat(expandWildcard(p));
+    });
+
+    let totalLines = 0;
+    let totalWords = 0;
+    let totalChars = 0;
+
+    allFiles.forEach(file => {
+      const result = wcFile(file, options);
+      if (result) {
+        totalLines += result.lines;
+        totalWords += result.words;
+        totalChars += result.chars;
+      }
+    });
+
+    if (allFiles.length > 1) {
+      console.log(
+        formatOutput(
+          { lines: totalLines, words: totalWords, chars: totalChars },
+          options,
+          "total"
+        )
+      );
+    }
+  });
+
+program.parse();