From 7e7ebfd09695d857447a3d8feb1595a0e296858c Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Sat, 28 Mar 2026 02:53:13 +0000
Subject: [PATCH 1/7] cat done

---
 implement-shell-tools/.gitignore       |  1 +
 implement-shell-tools/cat/customCat.js | 42 ++++++++++++++++++++++++++
 implement-shell-tools/package.json     |  3 ++
 3 files changed, 46 insertions(+)
 create mode 100644 implement-shell-tools/.gitignore
 create mode 100755 implement-shell-tools/cat/customCat.js
 create mode 100644 implement-shell-tools/package.json

diff --git a/implement-shell-tools/.gitignore b/implement-shell-tools/.gitignore
new file mode 100644
index 000000000..40b878db5
--- /dev/null
+++ b/implement-shell-tools/.gitignore
@@ -0,0 +1 @@
+node_modules/
\ No newline at end of file
diff --git a/implement-shell-tools/cat/customCat.js b/implement-shell-tools/cat/customCat.js
new file mode 100755
index 000000000..b58d5a214
--- /dev/null
+++ b/implement-shell-tools/cat/customCat.js
@@ -0,0 +1,42 @@
+#!/usr/bin/env node
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+import process from "node:process";
+
+program
+  .name("customCat")
+  .description("CLI command to concatenate and print files")
+  .option("-n, --number", "Number all output lines starting, at 1")
+  .option("-b, --nonBlank", "Number only non-blank lines, starting at 1")
+  .argument("<files...>", "Files to read");
+
+program.parse();
+
+const argv = program.args;
+const options = program.opts();
+
+let lineNumber = 1;
+
+for (const filePath of argv) {
+  try {
+    const content = await fs.readFile(filePath, "utf-8");
+    const lines = content.split("\n");
+
+    if (lines[lines.length - 1] === "") lines.pop();
+
+    lines.forEach((line, index) => {
+      if (options.nonBlank) {
+        if (line.trim() !== "") {
+          process.stdout.write(`${(index + 1).toString().padStart(6)} ${line}\n`);
+          lineNumber++;
+        } else process.stdout.write(`${line}\n`);
+      } else if (options.number) {
+        process.stdout.write(`${(index + 1).toString().padStart(6)} ${line}\n`);
+      } else {
+        process.stdout.write(`${line}\n`);
+      }
+    });
+  } catch (error) {
+    console.error(`customCat: ${filePath}: No such file or directory.`);
+  }
+}
diff --git a/implement-shell-tools/package.json b/implement-shell-tools/package.json
new file mode 100644
index 000000000..3dbc1ca59
--- /dev/null
+++ b/implement-shell-tools/package.json
@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

From 30170c8f1292c6683af6a3aa88d08e2f815f1bd0 Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Mon, 30 Mar 2026 21:06:44 +0100
Subject: [PATCH 2/7] feat: implement custom ls with -1 and -a support

---
 implement-shell-tools/cat/customCat.js  |  7 ++--
 implement-shell-tools/ls/customLs.js    | 53 +++++++++++++++++++++++++
 implement-shell-tools/package-lock.json | 20 ++++++++++
 implement-shell-tools/package.json      |  5 ++-
 4 files changed, 80 insertions(+), 5 deletions(-)
 create mode 100755 implement-shell-tools/ls/customLs.js
 create mode 100644 implement-shell-tools/package-lock.json

diff --git a/implement-shell-tools/cat/customCat.js b/implement-shell-tools/cat/customCat.js
index b58d5a214..3f0698cb5 100755
--- a/implement-shell-tools/cat/customCat.js
+++ b/implement-shell-tools/cat/customCat.js
@@ -15,8 +15,6 @@ program.parse();
 const argv = program.args;
 const options = program.opts();
 
-let lineNumber = 1;
-
 for (const filePath of argv) {
   try {
     const content = await fs.readFile(filePath, "utf-8");
@@ -27,8 +25,9 @@ for (const filePath of argv) {
     lines.forEach((line, index) => {
       if (options.nonBlank) {
         if (line.trim() !== "") {
-          process.stdout.write(`${(index + 1).toString().padStart(6)} ${line}\n`);
-          lineNumber++;
+          process.stdout.write(
+            `${(index + 1).toString().padStart(6)} ${line}\n`,
+          );
         } else process.stdout.write(`${line}\n`);
       } else if (options.number) {
         process.stdout.write(`${(index + 1).toString().padStart(6)} ${line}\n`);
diff --git a/implement-shell-tools/ls/customLs.js b/implement-shell-tools/ls/customLs.js
new file mode 100755
index 000000000..c17e77b12
--- /dev/null
+++ b/implement-shell-tools/ls/customLs.js
@@ -0,0 +1,53 @@
+#!/usr/bin/env node
+
+import process from "node:process";
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("customLs")
+  .description("List contents of a directory")
+  .option("-1", "Force output to be one entry per line")
+  .option("-a", "Include hidden files")
+  .argument("[path...]", "directories to list");
+
+program.parse();
+
+const options = program.opts();
+const targetPaths = program.args.length > 0 ? program.args : ["."];
+
+async function listDir(dirPath, showHeader) {
+  try {
+    let contents = await fs.readdir(dirPath);
+
+    if (options.a) {
+      contents.push(".", "..");
+    } else {
+      contents = contents.filter((name) => !name.startsWith("."));
+    }
+
+    contents.sort();
+
+    if (showHeader) {
+      process.stdout.write(`${dirPath}:\n`);
+    }
+
+    if (options["1"]) {
+      contents.forEach((item) => process.stdout.write(`${item}\n`));
+    } else {
+      process.stdout.write(`${contents.join("   ")}\n`);
+    }
+  } catch (error) {
+    console.error(`customLs: ${dirPath}: ${error.message}`);
+    process.exit(1);
+  }
+}
+
+for (let i = 0; i < targetPaths.length; i++) {
+  const path = targetPaths[i];
+  const isMultiplePath = targetPaths.length > 1;
+
+  await listDir(path, isMultiplePath);
+
+  if (isMultiplePath && i < targetPaths.length - 1) process.stdout.write(`\n`);
+}
diff --git a/implement-shell-tools/package-lock.json b/implement-shell-tools/package-lock.json
new file mode 100644
index 000000000..cdf736677
--- /dev/null
+++ b/implement-shell-tools/package-lock.json
@@ -0,0 +1,20 @@
+{
+  "name": "implement-shell-tools",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "commander": "^14.0.3"
+      }
+    },
+    "node_modules/commander": {
+      "version": "14.0.3",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-14.0.3.tgz",
+      "integrity": "sha512-H+y0Jo/T1RZ9qPP4Eh1pkcQcLRglraJaSLoyOtHxu6AapkjWVCy2Sit1QQ4x3Dng8qDlSsZEet7g5Pq06MvTgw==",
+      "engines": {
+        "node": ">=20"
+      }
+    }
+  }
+}
diff --git a/implement-shell-tools/package.json b/implement-shell-tools/package.json
index 3dbc1ca59..043047a15 100644
--- a/implement-shell-tools/package.json
+++ b/implement-shell-tools/package.json
@@ -1,3 +1,6 @@
 {
-  "type": "module"
+  "type": "module",
+  "dependencies": {
+    "commander": "^14.0.3"
+  }
 }

From 5a74b431a09f5a0c5eb19fbd17a2e88528baf831 Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Wed, 1 Apr 2026 16:35:28 +0100
Subject: [PATCH 3/7] feat: implement custom wc

---
 .gitignore                             |  1 +
 implement-shell-tools/cat/customCat.js |  4 +-
 implement-shell-tools/ls/customLs.js   |  4 +-
 implement-shell-tools/wc/customWc.js   | 69 ++++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 4 deletions(-)
 create mode 100755 implement-shell-tools/wc/customWc.js

diff --git a/.gitignore b/.gitignore
index 3c3629e64..0099691d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 node_modules
+demo*
diff --git a/implement-shell-tools/cat/customCat.js b/implement-shell-tools/cat/customCat.js
index 3f0698cb5..98770c107 100755
--- a/implement-shell-tools/cat/customCat.js
+++ b/implement-shell-tools/cat/customCat.js
@@ -4,7 +4,7 @@ import { promises as fs } from "node:fs";
 import process from "node:process";
 
 program
-  .name("customCat")
+  .name("ccat")
   .description("CLI command to concatenate and print files")
   .option("-n, --number", "Number all output lines starting, at 1")
   .option("-b, --nonBlank", "Number only non-blank lines, starting at 1")
@@ -36,6 +36,6 @@ for (const filePath of argv) {
       }
     });
   } catch (error) {
-    console.error(`customCat: ${filePath}: No such file or directory.`);
+    console.error(`ccat: ${filePath}: No such file or directory.`);
   }
 }
diff --git a/implement-shell-tools/ls/customLs.js b/implement-shell-tools/ls/customLs.js
index c17e77b12..928566ef4 100755
--- a/implement-shell-tools/ls/customLs.js
+++ b/implement-shell-tools/ls/customLs.js
@@ -5,7 +5,7 @@ import { program } from "commander";
 import { promises as fs } from "node:fs";
 
 program
-  .name("customLs")
+  .name("cls")
   .description("List contents of a directory")
   .option("-1", "Force output to be one entry per line")
   .option("-a", "Include hidden files")
@@ -38,7 +38,7 @@ async function listDir(dirPath, showHeader) {
       process.stdout.write(`${contents.join("   ")}\n`);
     }
   } catch (error) {
-    console.error(`customLs: ${dirPath}: ${error.message}`);
+    console.error(`cls: ${dirPath}: ${error.message}`);
     process.exit(1);
   }
 }
diff --git a/implement-shell-tools/wc/customWc.js b/implement-shell-tools/wc/customWc.js
new file mode 100755
index 000000000..0281db95e
--- /dev/null
+++ b/implement-shell-tools/wc/customWc.js
@@ -0,0 +1,69 @@
+#!/usr/bin/env node
+
+import { program } from "commander";
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+program
+  .name("cwc")
+  .description("Displays number of lines, words, and bytes in a file")
+  .option("-l, --lines", "Counts number of newline characters")
+  .option(
+    "-w, --words",
+    "Counts sequence of characters separated by whitespace",
+  )
+  .option("-c, --bytes", "Counts raw size of the files in bytes")
+  .argument("<files...>", "File(s) to read and count");
+
+program.parse();
+
+const options = program.opts();
+const files = program.args;
+
+const noFlags = !options.lines && !options.words && !options.bytes;
+
+let totalLines = 0;
+let totalWords = 0;
+let totalBytes = 0;
+
+async function countFiles(file) {
+  try {
+    const buffer = await fs.readFile(file);
+    const content = buffer.toString("utf-8");
+
+    const lineCount = content === "" ? 0 : content.split("\n").length - 1;
+    const wordCount = content.trim() ? content.trim().split(/\s+/).length : 0;
+    const byteCount = buffer.length;
+
+    totalLines += lineCount;
+    totalWords += wordCount;
+    totalBytes += byteCount;
+
+    let result = "";
+
+    if (options.lines || noFlags) result += `${String(lineCount).padStart(8)}`;
+    if (options.words || noFlags) result += `${String(wordCount).padStart(8)}`;
+    if (options.bytes || noFlags) result += `${String(byteCount).padStart(8)}`;
+
+    process.stdout.write(`${result} ${file}\n`);
+  } catch (error) {
+    console.error(`cwc: ${file}: ${error.message}`);
+    process.exit(1);
+  }
+}
+
+(async () => {
+  for (const file of files) {
+    await countFiles(file);
+  }
+
+  if (files.length > 1) {
+    let total = "";
+
+    if (options.lines || noFlags) total += `${String(totalLines).padStart(8)}`;
+    if (options.words || noFlags) total += `${String(totalWords).padStart(8)}`;
+    if (options.bytes || noFlags) total += `${String(totalBytes).padStart(8)}`;
+
+    process.stdout.write(`${total} total\n`);
+  }
+})();

From bd10e7c8bbaed8061c205b15999094926a532b28 Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Mon, 6 Jul 2026 19:16:18 +0100
Subject: [PATCH 4/7] fix: refactor index to use count instead

---
 implement-shell-tools/cat/customCat.js | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/implement-shell-tools/cat/customCat.js b/implement-shell-tools/cat/customCat.js
index 98770c107..fda55d141 100755
--- a/implement-shell-tools/cat/customCat.js
+++ b/implement-shell-tools/cat/customCat.js
@@ -1,4 +1,7 @@
 #!/usr/bin/env node
+
+
+
 import { program } from "commander";
 import { promises as fs } from "node:fs";
 import process from "node:process";
@@ -22,15 +25,18 @@ for (const filePath of argv) {
 
     if (lines[lines.length - 1] === "") lines.pop();
 
-    lines.forEach((line, index) => {
+    let count = 0;
+
+    lines.forEach((line) => {
       if (options.nonBlank) {
-        if (line.trim() !== "") {
+        if (line !== "") {
+          count++;
           process.stdout.write(
-            `${(index + 1).toString().padStart(6)} ${line}\n`,
+            `${count.toString().padStart(6)} ${line}\n`,
           );
         } else process.stdout.write(`${line}\n`);
       } else if (options.number) {
-        process.stdout.write(`${(index + 1).toString().padStart(6)} ${line}\n`);
+        process.stdout.write(`${(count++ + 1).toString().padStart(6)} ${line}\t`);
       } else {
         process.stdout.write(`${line}\n`);
       }

From 1e95febd4a20c9456610877029ff0e8f42a6d6d8 Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Mon, 6 Jul 2026 23:18:47 +0100
Subject: [PATCH 5/7] fix: implement ls to not exit when an error is
 encountered

---
 implement-shell-tools/cat/customCat.js | 10 ++++------
 implement-shell-tools/ls/customLs.js   |  6 +++++-
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/implement-shell-tools/cat/customCat.js b/implement-shell-tools/cat/customCat.js
index fda55d141..6779cbc6e 100755
--- a/implement-shell-tools/cat/customCat.js
+++ b/implement-shell-tools/cat/customCat.js
@@ -1,7 +1,5 @@
 #!/usr/bin/env node
 
-
-
 import { program } from "commander";
 import { promises as fs } from "node:fs";
 import process from "node:process";
@@ -31,12 +29,12 @@ for (const filePath of argv) {
       if (options.nonBlank) {
         if (line !== "") {
           count++;
-          process.stdout.write(
-            `${count.toString().padStart(6)} ${line}\n`,
-          );
+          process.stdout.write(`${count.toString().padStart(6)} ${line}\n`);
         } else process.stdout.write(`${line}\n`);
       } else if (options.number) {
-        process.stdout.write(`${(count++ + 1).toString().padStart(6)} ${line}\t`);
+        process.stdout.write(
+          `${(count++ + 1).toString().padStart(6)} ${line}\t`,
+        );
       } else {
         process.stdout.write(`${line}\n`);
       }
diff --git a/implement-shell-tools/ls/customLs.js b/implement-shell-tools/ls/customLs.js
index 928566ef4..2cd3eccdd 100755
--- a/implement-shell-tools/ls/customLs.js
+++ b/implement-shell-tools/ls/customLs.js
@@ -16,6 +16,8 @@ program.parse();
 const options = program.opts();
 const targetPaths = program.args.length > 0 ? program.args : ["."];
 
+let hadError = false;
+
 async function listDir(dirPath, showHeader) {
   try {
     let contents = await fs.readdir(dirPath);
@@ -39,7 +41,7 @@ async function listDir(dirPath, showHeader) {
     }
   } catch (error) {
     console.error(`cls: ${dirPath}: ${error.message}`);
-    process.exit(1);
+    hadError = true;
   }
 }
 
@@ -51,3 +53,5 @@ for (let i = 0; i < targetPaths.length; i++) {
 
   if (isMultiplePath && i < targetPaths.length - 1) process.stdout.write(`\n`);
 }
+
+if (hadError) process.exit(1);

From 4cb8e57f28e1ceef6aeea1cd264c56d58213255e Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Mon, 6 Jul 2026 23:24:21 +0100
Subject: [PATCH 6/7] fix: Error handling

---
 implement-shell-tools/wc/customWc.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/implement-shell-tools/wc/customWc.js b/implement-shell-tools/wc/customWc.js
index 0281db95e..847bd4032 100755
--- a/implement-shell-tools/wc/customWc.js
+++ b/implement-shell-tools/wc/customWc.js
@@ -26,6 +26,8 @@ let totalLines = 0;
 let totalWords = 0;
 let totalBytes = 0;
 
+let hadError = false;
+
 async function countFiles(file) {
   try {
     const buffer = await fs.readFile(file);
@@ -48,7 +50,7 @@ async function countFiles(file) {
     process.stdout.write(`${result} ${file}\n`);
   } catch (error) {
     console.error(`cwc: ${file}: ${error.message}`);
-    process.exit(1);
+    hadError = true;
   }
 }
 
@@ -66,4 +68,6 @@ async function countFiles(file) {
 
     process.stdout.write(`${total} total\n`);
   }
+
+  if (hadError) process.exit(1);
 })();

From cc3a482a3033249e81c5e601eb1e1b4544f4885a Mon Sep 17 00:00:00 2001
From: JanefrancessC <janefrancesschioma@gmail.com>
Date: Mon, 6 Jul 2026 23:32:12 +0100
Subject: [PATCH 7/7] fix: using tabs rather than space

---
 implement-shell-tools/cat/customCat.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/implement-shell-tools/cat/customCat.js b/implement-shell-tools/cat/customCat.js
index 6779cbc6e..92d5197e1 100755
--- a/implement-shell-tools/cat/customCat.js
+++ b/implement-shell-tools/cat/customCat.js
@@ -29,11 +29,11 @@ for (const filePath of argv) {
       if (options.nonBlank) {
         if (line !== "") {
           count++;
-          process.stdout.write(`${count.toString().padStart(6)} ${line}\n`);
+          process.stdout.write(`${count.toString().padStart(6)}\t${line}\n`);
         } else process.stdout.write(`${line}\n`);
       } else if (options.number) {
         process.stdout.write(
-          `${(count++ + 1).toString().padStart(6)} ${line}\t`,
+          `${(count++ + 1).toString().padStart(6)}\t${line}\n`,
         );
       } else {
         process.stdout.write(`${line}\n`);