complete implement-shell-tools task

Author: shaghayeghfar

implement-shell-tools/cat/README.md

@@ -6,11 +6,11 @@ Your task is to implement your own version of `cat`.
 
 It must act the same as `cat` would, if run from the directory containing this README.md file, for the following command lines:
 
-* `cat sample-files/1.txt`
-* `cat -n sample-files/1.txt`
-* `cat sample-files/*.txt`
-* `cat -n sample-files/*.txt`
-* `cat -b sample-files/3.txt`
+- `cat sample-files/1.txt`
+- `cat -n sample-files/1.txt`
+- `cat sample-files/*.txt`
+- `cat -n sample-files/*.txt`
+- `cat -b sample-files/3.txt`
 
 Matching any additional behaviours or flags are optional stretch goals.
 

implement-shell-tools/cat/cat.js

@@ -0,0 +1,44 @@
+const fs = require("fs");
+
+// input from terminal
+const args = process.argv.slice(2);
+
+// check flags
+const hasN = args.includes("-n");
+const hasB = args.includes("-b");
+
+// get only file names
+const files = args.filter((arg) => !arg.startsWith("-"));
+
+let count = 1;
+
+// go through each file
+for (let i = 0; i < files.length; i++) {
+  const content = fs.readFileSync(files[i], "utf-8");
+
+  const lines = content.split("\n");
+
+  // go through each line
+  for (let j = 0; j < lines.length; j++) {
+    const line = lines[j];
+
+    // if -b (number non-empty lines)
+    if (hasB) {
+      if (line.trim() !== "") {
+        console.log(count + " " + line);
+        count++;
+      } else {
+        console.log("");
+      }
+    }
+    // if -n (number all lines)
+    else if (hasN) {
+      console.log(count + " " + line);
+      count++;
+    }
+    // no flags
+    else {
+      console.log(line);
+    }
+  }
+}

implement-shell-tools/ls/README.md

@@ -6,9 +6,9 @@ Your task is to implement your own version of `ls`.
 
 It must act the same as `ls` would, if run from the directory containing this README.md file, for the following command lines:
 
-* `ls -1`
-* `ls -1 sample-files`
-* `ls -1 -a sample-files`
+- `ls -1`
+- `ls -1 sample-files`
+- `ls -1 -a sample-files`
 
 Matching any additional behaviours or flags are optional stretch goals.
 

implement-shell-tools/ls/ls.js

@@ -0,0 +1,25 @@
+const fs = require("fs");
+
+// input from terminal
+const args = process.argv.slice(2);
+
+// flags
+const showAll = args.includes("-a");
+
+// get folder (default = current folder)
+const folder = args.filter((arg) => !arg.startsWith("-"))[0] || ".";
+
+// read directory
+const files = fs.readdirSync(folder);
+
+// loop and print
+for (let i = 0; i < files.length; i++) {
+  const file = files[i];
+
+  // skip hidden files unless -a is used
+  if (!showAll && file.startsWith(".")) {
+    continue;
+  }
+
+  console.log(file);
+}

implement-shell-tools/wc/README.md

@@ -6,11 +6,11 @@ Your task is to implement your own version of `wc`.
 
 It must act the same as `wc` would, if run from the directory containing this README.md file, for the following command lines:
 
-* `wc sample-files/*`
-* `wc -l sample-files/3.txt`
-* `wc -w sample-files/3.txt`
-* `wc -c sample-files/3.txt`
-* `wc -l sample-files/*`
+- `wc sample-files/*`
+- `wc -l sample-files/3.txt`
+- `wc -w sample-files/3.txt`
+- `wc -c sample-files/3.txt`
+- `wc -l sample-files/*`
 
 Matching any additional behaviours or flags are optional stretch goals.
 

implement-shell-tools/wc/wc.js

@@ -0,0 +1,54 @@
+const fs = require("fs");
+
+// get CLI arguments
+const args = process.argv.slice(2);
+
+// flags
+const showLines = args.includes("-l");
+const showWords = args.includes("-w");
+const showBytes = args.includes("-c");
+
+// get files (remove flags)
+const files = args.filter((arg) => !arg.startsWith("-"));
+
+// helper functions
+function countLines(text) {
+  return text.split("\n").length - 1;
+}
+
+function countWords(text) {
+  return text.trim().split(/\s+/).filter(Boolean).length;
+}
+
+function countBytes(text) {
+  return Buffer.byteLength(text, "utf8");
+}
+
+// loop through files
+for (let i = 0; i < files.length; i++) {
+  const file = files[i];
+
+  try {
+    const content = fs.readFileSync(file, "utf8");
+
+    const lines = countLines(content);
+    const words = countWords(content);
+    const bytes = countBytes(content);
+
+    let output = "";
+
+    // if no flag → show all
+    if (!showLines && !showWords && !showBytes) {
+      output = `${lines} ${words} ${bytes} ${file}`;
+    } else {
+      if (showLines) output += `${lines} `;
+      if (showWords) output += `${words} `;
+      if (showBytes) output += `${bytes} `;
+      output += file;
+    }
+
+    console.log(output.trim());
+  } catch (err) {
+    console.error(`wc: cannot open ${file}`);
+  }
+}