London | 26-SDC-Mar | Beko | Sprint 3 | Implement Shell Tools

implement-shell-tools/cat/catFile.mjs

@@ -0,0 +1,44 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const argv = process.argv.slice(2);
+
+const dash = argv.filter(arg => arg.startsWith('-'));
+const filePaths = argv.filter(arg => !arg.startsWith('-'));
+
+const showLineNumbers = dash.includes('-n');
+const showNonBlank = dash.includes('-b');
+
+let lineCounter = 1;
+
+for (const filePath of filePaths) {
+    let content;
+    try {
+        content = await fs.readFile(filePath, 'utf8');
+    } catch {
+        console.error(`cat: ${filePath}: No file or directory exists`);
+        process.exit(1);
+    }
+
+    const lines = content.split('\n');
+
+    if (lines[lines.length - 1] === '') lines.pop();
+
+    for (const line of lines) {
+        const isBlank = line.trim() === '';
+
+        if (showNonBlank) {
+            if (isBlank) {
+                console.log('');
+            } else {
+                console.log(`${String(lineCounter).padStart(6)}\t${line}`);
+                lineCounter++;
+            }
+        } else if (showLineNumbers) {
+            console.log(`${String(lineCounter).padStart(6)}\t${line}`);
+            lineCounter++;
+        } else {
+            console.log(line);
+        }
+    }
+}

implement-shell-tools/ls/lsFile.mjs

@@ -0,0 +1,19 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const argv = process.argv.slice(2);
+
+const dash = argv.filter(arg => arg.startsWith('-'));
+const paths = argv.filter(arg => !arg.startsWith('-'));
+
+const showAll = dash.includes('-a');
+
+const targetDir = paths[0] ?? '.';
+
+const entries = await fs.readdir(targetDir);
+
+const result = showAll ? ['.', '..', ...entries] : entries.filter(e => !e.startsWith('.'));
+
+for (const entry of result) {
+    console.log(entry);
+}

implement-shell-tools/wc/wcFile.mjs

@@ -0,0 +1,55 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const argv = process.argv.slice(2);
+
+const dash = argv.filter(arg => arg.startsWith('-'));
+const filePaths = argv.filter(arg => !arg.startsWith('-'));
+
+const forLines = dash.includes('-l');
+const forWords = dash.includes('-w');
+const forBytes = dash.includes('-c');
+
+let totalLines = 0;
+let totalWords = 0;
+let totalBytes = 0;
+
+for (const filePath of filePaths) {
+    let content;
+    try {
+        content = await fs.readFile(filePath, 'utf8');
+    } catch {
+        console.error(`wc: ${filePath}: No file or directory exists`);
+        process.exit(1);
+    }
+
+    const lines = content.split('\n').length - 1;
+    const words = content.trim() === '' ? 0 : content.trim().split(/\s+/).length;
+    const bytes = Buffer.byteLength(content, 'utf8');
+
+    totalLines += lines;
+    totalWords += words;
+    totalBytes += bytes;
+
+    if (forLines) {
+        console.log(`${String(lines).padStart(8)} ${filePath}`);
+    } else if (forWords) {
+        console.log(`${String(words).padStart(8)} ${filePath}`);
+    } else if (forBytes) {
+        console.log(`${String(bytes).padStart(8)} ${filePath}`);
+    } else {
+        console.log(`${String(lines).padStart(8)} ${String(words).padStart(8)} ${String(bytes).padStart(8)} ${filePath}`);
+    }
+}
+
+if (filePaths.length > 1) {
+    if (forLines) {
+        console.log(`${String(totalLines).padStart(8)} total`);
+    } else if (forWords) {
+        console.log(`${String(totalWords).padStart(8)} total`);
+    } else if (forBytes) {
+        console.log(`${String(totalBytes).padStart(8)} total`);
+    } else {
+        console.log(`${String(totalLines).padStart(8)} ${String(totalWords).padStart(8)} ${String(totalBytes).padStart(8)} total`);
+    }
+}