From 3de450eac5fcd907f86ecbf3ce852324c265f6b7 Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Tue, 2 Dec 2025 22:07:23 +0000
Subject: [PATCH 1/7] Intalled commader library; Create cat.js file

---
 implement-shell-tools/cat/.gitignore          |  2 ++
 implement-shell-tools/cat/cat.js              | 27 +++++++++++++++++++
 implement-shell-tools/cat/ls/README.md        | 15 +++++++++++
 .../cat/ls/sample-files/.hidden.txt           |  0
 .../cat/ls/sample-files/1.txt                 |  1 +
 .../cat/ls/sample-files/2.txt                 |  1 +
 .../cat/ls/sample-files/3.txt                 |  5 ++++
 .../cat/ls/sample-files/dir/a.txt             |  0
 .../cat/ls/sample-files/dir/b.txt             |  0
 .../cat/ls/sample-files/dir/subdir/x.txt      |  0
 .../cat/ls/sample-files/dir/subdir/y.txt      |  0
 .../cat/ls/sample-files/dir/subdir/z.txt      |  0
 implement-shell-tools/cat/package-lock.json   | 21 +++++++++++++++
 implement-shell-tools/cat/package.json        |  6 +++++
 14 files changed, 78 insertions(+)
 create mode 100644 implement-shell-tools/cat/.gitignore
 create mode 100644 implement-shell-tools/cat/cat.js
 create mode 100644 implement-shell-tools/cat/ls/README.md
 create mode 100644 implement-shell-tools/cat/ls/sample-files/.hidden.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/1.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/2.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/3.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/dir/a.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/dir/b.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/dir/subdir/x.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/dir/subdir/y.txt
 create mode 100644 implement-shell-tools/cat/ls/sample-files/dir/subdir/z.txt
 create mode 100644 implement-shell-tools/cat/package-lock.json
 create mode 100644 implement-shell-tools/cat/package.json

diff --git a/implement-shell-tools/cat/.gitignore b/implement-shell-tools/cat/.gitignore
new file mode 100644
index 000000000..f31e3d79c
--- /dev/null
+++ b/implement-shell-tools/cat/.gitignore
@@ -0,0 +1,2 @@
+# Dependency directory
+/node_modules
diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
new file mode 100644
index 000000000..62d8593f2
--- /dev/null
+++ b/implement-shell-tools/cat/cat.js
@@ -0,0 +1,27 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import process from "node:process";
+
+program
+  .name("count-containing-words")
+  .description("Counts words in a file that contain a particular character")
+  .option("-c, --char <char>", "The character to search for", "e")
+  .argument("<path>", "The file path to process");
+
+program.parse();
+
+const argv = program.args;
+if (argv.length != 1) {
+  console.error(
+    `Expected exactly 1 argument (a path) to be passed but got ${argv.length}.`
+  );
+  process.exit(1);
+}
+const path = argv[0];
+const char = program.opts().char;
+
+const content = await fs.readFile(path, "utf-8");
+const countOfWordsContainingChar = content
+  .split(" ")
+  .filter((word) => word.includes(char)).length;
+console.log(countOfWordsContainingChar);
diff --git a/implement-shell-tools/cat/ls/README.md b/implement-shell-tools/cat/ls/README.md
new file mode 100644
index 000000000..edbfb811a
--- /dev/null
+++ b/implement-shell-tools/cat/ls/README.md
@@ -0,0 +1,15 @@
+# Implement `ls`
+
+You should already be familiar with the `ls` command line tool.
+
+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`
+
+Matching any additional behaviours or flags are optional stretch goals.
+
+We recommend you start off supporting just `-1`, then adding support for `-a`.
diff --git a/implement-shell-tools/cat/ls/sample-files/.hidden.txt b/implement-shell-tools/cat/ls/sample-files/.hidden.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/implement-shell-tools/cat/ls/sample-files/1.txt b/implement-shell-tools/cat/ls/sample-files/1.txt
new file mode 100644
index 000000000..ed7bf7d08
--- /dev/null
+++ b/implement-shell-tools/cat/ls/sample-files/1.txt
@@ -0,0 +1 @@
+Once upon a time...
diff --git a/implement-shell-tools/cat/ls/sample-files/2.txt b/implement-shell-tools/cat/ls/sample-files/2.txt
new file mode 100644
index 000000000..c2b8f0d39
--- /dev/null
+++ b/implement-shell-tools/cat/ls/sample-files/2.txt
@@ -0,0 +1 @@
+There was a house made of gingerbread.
diff --git a/implement-shell-tools/cat/ls/sample-files/3.txt b/implement-shell-tools/cat/ls/sample-files/3.txt
new file mode 100644
index 000000000..cdba09987
--- /dev/null
+++ b/implement-shell-tools/cat/ls/sample-files/3.txt
@@ -0,0 +1,5 @@
+It looked delicious.
+I was tempted to take a bite of it.
+But this seemed like a bad idea...
+
+There's more to come, though...
diff --git a/implement-shell-tools/cat/ls/sample-files/dir/a.txt b/implement-shell-tools/cat/ls/sample-files/dir/a.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/implement-shell-tools/cat/ls/sample-files/dir/b.txt b/implement-shell-tools/cat/ls/sample-files/dir/b.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/implement-shell-tools/cat/ls/sample-files/dir/subdir/x.txt b/implement-shell-tools/cat/ls/sample-files/dir/subdir/x.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/implement-shell-tools/cat/ls/sample-files/dir/subdir/y.txt b/implement-shell-tools/cat/ls/sample-files/dir/subdir/y.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/implement-shell-tools/cat/ls/sample-files/dir/subdir/z.txt b/implement-shell-tools/cat/ls/sample-files/dir/subdir/z.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/implement-shell-tools/cat/package-lock.json b/implement-shell-tools/cat/package-lock.json
new file mode 100644
index 000000000..11da220f0
--- /dev/null
+++ b/implement-shell-tools/cat/package-lock.json
@@ -0,0 +1,21 @@
+{
+  "name": "cat",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "commander": "^14.0.2"
+      }
+    },
+    "node_modules/commander": {
+      "version": "14.0.2",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-14.0.2.tgz",
+      "integrity": "sha512-TywoWNNRbhoD0BXs1P3ZEScW8W5iKrnbithIl0YH+uCmBd0QpPOA8yc82DS3BIE5Ma6FnBVUsJ7wVUDz4dvOWQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      }
+    }
+  }
+}
diff --git a/implement-shell-tools/cat/package.json b/implement-shell-tools/cat/package.json
new file mode 100644
index 000000000..76dcd3f7a
--- /dev/null
+++ b/implement-shell-tools/cat/package.json
@@ -0,0 +1,6 @@
+{
+  "type": "module",
+  "dependencies": {
+    "commander": "^14.0.2"
+  }
+}

From 6dd0b3a7f8a484d939363bc3420ba98ab4c429d5 Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Wed, 3 Dec 2025 00:08:11 +0000
Subject: [PATCH 2/7] implement cat command with -n and -b flag support

---
 implement-shell-tools/cat/cat.js | 55 +++++++++++++++++++++-----------
 1 file changed, 36 insertions(+), 19 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index 62d8593f2..31ecce055 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -3,25 +3,42 @@ import { promises as fs } from "node:fs";
 import process from "node:process";
 
 program
-  .name("count-containing-words")
-  .description("Counts words in a file that contain a particular character")
-  .option("-c, --char <char>", "The character to search for", "e")
-  .argument("<path>", "The file path to process");
+  .name("display-file-content")
+  .description("Implement cat command with -n and -b flag support")
+  .option("-n, --number-all-lines", "Number every line in the file")
+  .option("-b, --number-non-empty-lines", "Number non empty lines in the file")
+  .argument("<paths...>", "File paths to process");
 
-program.parse();
+program.parse(process.argv);
 
-const argv = program.args;
-if (argv.length != 1) {
-  console.error(
-    `Expected exactly 1 argument (a path) to be passed but got ${argv.length}.`
-  );
-  process.exit(1);
-}
-const path = argv[0];
-const char = program.opts().char;
+const args = program.args; //Array all file paths
 
-const content = await fs.readFile(path, "utf-8");
-const countOfWordsContainingChar = content
-  .split(" ")
-  .filter((word) => word.includes(char)).length;
-console.log(countOfWordsContainingChar);
+//read flags user typed and return them as object.
+const opts = program.opts();
+
+let lineNumber = 1;
+
+// Loop over every filepath in args
+args.forEach(async (filepath) => {
+  const content = await fs.readFile(filepath, "utf8");
+  const lines = content.split("\n");
+
+  lines.forEach((line) => {
+    if (opts.numberAllLines) {
+      // -n: number every line
+      console.log(`${lineNumber} ${line}`);
+      lineNumber++;
+    } else if (opts.numberNonEmptyLines) {
+      // -b: number non-empty lines only
+      if (line.trim() === "") {
+        console.log(line);
+      } else {
+        console.log(`${lineNumber} ${line}`);
+        lineNumber++;
+      }
+    } else {
+      // No flag: just print
+      console.log(line);
+    }
+  });
+});

From 5684c3700dc79a8ed88261cc66edeb1d5181e0d0 Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Thu, 4 Dec 2025 00:26:25 +0000
Subject: [PATCH 3/7] Implement ls command to list files in directory with -1
 flag and -a flag

---
 implement-shell-tools/ls/ls.js | 42 ++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 implement-shell-tools/ls/ls.js

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
new file mode 100644
index 000000000..9919dee20
--- /dev/null
+++ b/implement-shell-tools/ls/ls.js
@@ -0,0 +1,42 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("list-files-in-directory")
+  .description("Implement ls command to list files in directory")
+  .option("-1, --one-per-line", "list files one per line")
+  .option("-a, --allFiles", "list all files including hidden ones")
+  .argument("[paths...]", "File paths to process");
+
+program.parse(process.argv);
+
+// options and path from commander.
+const opts = program.opts();
+
+let paths = program.args; // array of paths user typed
+if (paths.length === 0) {
+  paths = ["."];
+}
+
+for (const directoryPath of paths) {
+  let entries;
+  try {
+    entries = await fs.readdir(directoryPath);
+  } catch (err) {
+    console.error(`ls: cannot access '${directoryPath}': ${err.message}`);
+    continue; // move to next path if this one fails
+  }
+
+  if (!opts.allFiles) {
+    entries = entries.filter((name) => !name.startsWith("."));
+  }
+
+  if (opts.onePerLine) {
+    entries.forEach((name) => {
+      console.log(name);
+    });
+  } else {
+    //print files in one line if -1 is not used
+    console.log(entries.join(" "));
+  }
+}

From 7a43ee808647387f8f8c9797f344233323cae67e Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Thu, 4 Dec 2025 18:21:07 +0000
Subject: [PATCH 4/7] Implement wc command to count  lines, words and
 characters

---
 implement-shell-tools/wc/wc.js | 80 ++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 implement-shell-tools/wc/wc.js

diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
new file mode 100644
index 000000000..14895f605
--- /dev/null
+++ b/implement-shell-tools/wc/wc.js
@@ -0,0 +1,80 @@
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import process from "node:process";
+
+program
+  .name("wc command")
+  .description("Implement wc command to count words and lines")
+  .option("-l,", "show number of lines only")
+  .option("-w,", "show number of words only")
+  .option("-c,", "show number of characters only")
+  .argument("[path...]", "The file path to process");
+
+program.parse(process.argv);
+
+const opts = program.opts();
+let paths = program.args;
+
+if (paths.length === 0) {
+  console.error("wc: no file specified");
+  process.exit(1);
+}
+
+let totals = { lines: 0, words: 0, chars: 0 };
+
+for (const filePath of paths) {
+  let content;
+  try {
+    content = await fs.readFile(filePath, "utf8");
+  } catch (err) {
+    console.error(`wc: cannot read file "${filePath}": ${err.message}`);
+    continue; // move on to next path
+  }
+
+  const lineCount = content.split("n").length;
+
+  const wordCount = content.split(/\s+/).filter(Boolean).length;
+
+  const charCount = content.length;
+
+  totals.lines += lineCount;
+  totals.words += wordCount;
+  totals.chars += charCount;
+
+  // Decide what to print depending on flags
+  if (!opts.l && !opts.w && !opts.c) {
+    console.log(`${lineCount} ${wordCount} ${charCount} ${filePath}`);
+    continue;
+  }
+
+  if (opts.l) {
+    console.log(`${lineCount} ${filePath}`);
+  }
+
+  if (opts.w) {
+    console.log(`${wordCount} ${filePath}`);
+  }
+
+  if (opts.c) {
+    console.log(`${charCount} ${filePath}`);
+  }
+}
+
+//Print totals if there are multiple files
+if (paths.length > 1) {
+  if (!opts.l && !opts.w && !opts.c) {
+    console.log(`${totals.lines} ${totals.words} ${totals.chars} total`);
+  }
+
+  if (opts.l) {
+    console.log(`${totals.lines} total`);
+  }
+
+  if (opts.w) {
+    console.log(`${totals.words} total`);
+  }
+
+  if (opts.c) {
+    console.log(`${totals.chars} total`);
+  }
+}

From 0acf2ca008ed21e1dd271ddb00cb28cb6f63592c Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Tue, 10 Feb 2026 15:02:03 +0000
Subject: [PATCH 5/7] refactor: improve readability by Deleting comments and
 replacing forEach with for...of loops

---
 implement-shell-tools/cat/cat.js | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index 31ecce055..e761d144e 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -11,34 +11,32 @@ program
 
 program.parse(process.argv);
 
-const args = program.args; //Array all file paths
+const filepaths = program.args;
 
-//read flags user typed and return them as object.
-const opts = program.opts();
+const options = program.opts();
 
 let lineNumber = 1;
 
-// Loop over every filepath in args
-args.forEach(async (filepath) => {
-  const content = await fs.readFile(filepath, "utf8");
-  const lines = content.split("\n");
+for (const filepath of filepaths) {
+  const fileContent = await fs.readFile(filepath, "utf8");
+  const lines = fileContent.split("\n");
 
-  lines.forEach((line) => {
-    if (opts.numberAllLines) {
-      // -n: number every line
+  for (const line of lines) {
+    if (options.numberAllLines) {
       console.log(`${lineNumber} ${line}`);
       lineNumber++;
-    } else if (opts.numberNonEmptyLines) {
-      // -b: number non-empty lines only
+      continue;
+    }
+
+    if (options.numberNonEmptyLines) {
       if (line.trim() === "") {
         console.log(line);
       } else {
         console.log(`${lineNumber} ${line}`);
         lineNumber++;
       }
-    } else {
-      // No flag: just print
-      console.log(line);
+      continue;
     }
-  });
-});
+    console.log(line);
+  }
+}

From 3c7c4f7ba7ac6ecb489d6b352f78aab46a421b33 Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Tue, 10 Feb 2026 15:30:46 +0000
Subject: [PATCH 6/7] refactor: improve naming and simplify ls filtering logic

---
 implement-shell-tools/ls/ls.js | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 9919dee20..e62ce5606 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -10,33 +10,30 @@ program
 
 program.parse(process.argv);
 
-// options and path from commander.
-const opts = program.opts();
+const options = program.opts();
 
-let paths = program.args; // array of paths user typed
-if (paths.length === 0) {
-  paths = ["."];
-}
+let paths = program.args;
+if (paths.length === 0) paths = ["."];
 
 for (const directoryPath of paths) {
-  let entries;
+  let fileNames;
+
   try {
-    entries = await fs.readdir(directoryPath);
+    fileNames = await fs.readdir(directoryPath);
   } catch (err) {
     console.error(`ls: cannot access '${directoryPath}': ${err.message}`);
-    continue; // move to next path if this one fails
+    continue;
   }
 
-  if (!opts.allFiles) {
-    entries = entries.filter((name) => !name.startsWith("."));
-  }
+  fileNames = fileNames.filter(
+    (file) => options.allFiles || !file.startsWith("."),
+  );
 
-  if (opts.onePerLine) {
-    entries.forEach((name) => {
-      console.log(name);
-    });
+  if (options.onePerLine) {
+    for (const file of fileNames) {
+      console.log(file);
+    }
   } else {
-    //print files in one line if -1 is not used
-    console.log(entries.join(" "));
+    console.log(fileNames.join(" "));
   }
 }

From c192601b14665b84c897cd7e5680144ff2f1a69b Mon Sep 17 00:00:00 2001
From: ike-agu <ikennaww@yahoo.fr>
Date: Tue, 10 Feb 2026 17:01:03 +0000
Subject: [PATCH 7/7] fix wc flags and align behavior with Unix wc

---
 implement-shell-tools/wc/wc.js | 63 +++++++++++++---------------------
 1 file changed, 23 insertions(+), 40 deletions(-)

diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
index 14895f605..66cd286d4 100644
--- a/implement-shell-tools/wc/wc.js
+++ b/implement-shell-tools/wc/wc.js
@@ -1,14 +1,13 @@
 import { program } from "commander";
 import { promises as fs } from "node:fs";
-import process from "node:process";
 
 program
   .name("wc command")
   .description("Implement wc command to count words and lines")
-  .option("-l,", "show number of lines only")
-  .option("-w,", "show number of words only")
-  .option("-c,", "show number of characters only")
-  .argument("[path...]", "The file path to process");
+  .option("-l, --lines", "show number of lines only")
+  .option("-w, --words", "show number of words only")
+  .option("-c, --chars", "show number of characters only")
+  .argument("[paths...]", "The file path to process");
 
 program.parse(process.argv);
 
@@ -16,8 +15,7 @@ const opts = program.opts();
 let paths = program.args;
 
 if (paths.length === 0) {
-  console.error("wc: no file specified");
-  process.exit(1);
+  paths = ["."];
 }
 
 let totals = { lines: 0, words: 0, chars: 0 };
@@ -28,53 +26,38 @@ for (const filePath of paths) {
     content = await fs.readFile(filePath, "utf8");
   } catch (err) {
     console.error(`wc: cannot read file "${filePath}": ${err.message}`);
-    continue; // move on to next path
+    continue; 
   }
 
-  const lineCount = content.split("n").length;
-
+  const lineCount = content.split("\n").length;
   const wordCount = content.split(/\s+/).filter(Boolean).length;
-
   const charCount = content.length;
 
   totals.lines += lineCount;
   totals.words += wordCount;
   totals.chars += charCount;
 
-  // Decide what to print depending on flags
-  if (!opts.l && !opts.w && !opts.c) {
-    console.log(`${lineCount} ${wordCount} ${charCount} ${filePath}`);
-    continue;
-  }
-
-  if (opts.l) {
-    console.log(`${lineCount} ${filePath}`);
-  }
-
-  if (opts.w) {
-    console.log(`${wordCount} ${filePath}`);
-  }
+  const output = [];
 
-  if (opts.c) {
-    console.log(`${charCount} ${filePath}`);
+  if (!opts.lines && !opts.words && !opts.chars) {
+    output.push(lineCount, wordCount, charCount);
+  } else {
+    if (opts.lines) output.push(lineCount);
+    if (opts.words) output.push(wordCount);
+    if (opts.chars) output.push(charCount);
   }
+  console.log(`${output.join(" ")} ${filePath}`);
 }
 
-//Print totals if there are multiple files
 if (paths.length > 1) {
-  if (!opts.l && !opts.w && !opts.c) {
-    console.log(`${totals.lines} ${totals.words} ${totals.chars} total`);
-  }
-
-  if (opts.l) {
-    console.log(`${totals.lines} total`);
-  }
-
-  if (opts.w) {
-    console.log(`${totals.words} total`);
-  }
+  const totalOutput = [];
 
-  if (opts.c) {
-    console.log(`${totals.chars} total`);
+  if (!opts.lines && !opts.words && !opts.chars) {
+    totalOutput.push(totals.lines, totals.words, totals.chars);
+  } else {
+    if (opts.lines) totalOutput.push(totals.lines);
+    if (opts.words) totalOutput.push(totals.words);
+    if (opts.chars) totalOutput.push(totals.chars);
   }
+  console.log(`${totalOutput.join(" ")} total`);
 }