From 708e4cebc8aac3a1f5e1aa9a0c402397929eb9d0 Mon Sep 17 00:00:00 2001
From: Ebrahim Beiaty <ebrahimbeiaty@gmail.com>
Date: Sat, 14 Mar 2026 14:32:41 +0000
Subject: [PATCH 1/4]  implements-shell-tool

---
 implement-shell-tools/cat/cat.js | 76 ++++++++++++++++++++++++++++++++
 implement-shell-tools/ls/ls.js   | 52 ++++++++++++++++++++++
 implement-shell-tools/wc/wc.js   | 71 +++++++++++++++++++++++++++++
 3 files changed, 199 insertions(+)
 create mode 100644 implement-shell-tools/cat/cat.js
 create mode 100644 implement-shell-tools/ls/ls.js
 create mode 100755 implement-shell-tools/wc/wc.js

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
new file mode 100644
index 000000000..2bdbfc039
--- /dev/null
+++ b/implement-shell-tools/cat/cat.js
@@ -0,0 +1,76 @@
+#!/usr/bin/env node
+const fs = require('fs');
+const path = require('path');
+
+//shared line counter across all files(matches cat -n)
+let globalLineCounter = 1;
+
+function printFile(filePath, options) {
+    try {
+        const content = fs.readFileSync(filePath, 'utf-8');
+        const lines = content.split('\n');
+
+        lines.forEach((line) => {
+            if(options.numberNonEmpty) {
+                //-b option: number non-empty lines
+                if(line.trim()) {
+                    process.stdout.write(
+                        `${String(globalLineCounter).padStart(6)}\t${line}\n`
+                    );
+                    globalLineCounter++;
+                } else {
+                    process.stdout.write('\n');
+                }
+            } else if(options.numberAll) {
+                //-n option: number all lines
+                process.stdout.write(
+                    `${String(globalLineCounter).padStart(6)}\t${line}\n`
+                );
+                globalLineCounter++;
+            } else {
+                //default: just print the line
+                process.stdout.write(line + '\n');
+            }
+    });
+
+    } catch (error) {
+        console.error(`Error reading file ${filePath}: ${error.message}`);
+    }
+}
+
+function main() {
+    const args = process.argv.slice(2);
+    const options = {
+        numberNonEmpty: false,
+        numberAll: false,
+    };
+    const filePatterns = [];
+
+    args.forEach((arg) => {
+        if(arg === '-n') {
+            options.numberAll = true;
+        } else if(arg === '-b') {
+            options.numberNonEmpty = true;
+        } else {
+            filePatterns.push(arg);
+        }
+    });
+    // -b takes precedence over -n
+    if(options.numberNonEmpty) {
+        options.numberAll = false;
+    }
+
+    if(filePatterns.length === 0) {
+        console.log("cat: missing file operand");
+        process.exit(1);
+    }
+
+    const files = filePatterns;
+
+    files.forEach((file) => {
+        const resolvedPath = path.resolve(process.cwd(), file);
+        printFile(resolvedPath, options);
+    });
+    }
+
+main();
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
new file mode 100644
index 000000000..7ba9c99cb
--- /dev/null
+++ b/implement-shell-tools/ls/ls.js
@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+const fs = require('node:fs');
+const path = require('node:path');
+
+function listDirectory(dirPath, showAll, onePerLine) {
+    try {
+        const entries = fs.readdirSync(dirPath, { withFileTypes: true });
+        const filtered = entries.filter((entry) => showAll || !entry.name.startsWith('.'));
+
+        if(onePerLine) {
+            filtered.forEach(entry => console.log(entry.name));
+        } else {
+            const names = filtered.map(entry => entry.name);
+            console.log(names.join('  '));
+        }
+        } catch (error) {
+        console.error(`Error reading directory ${dirPath}: ${error.message}`);
+    }
+}
+function main() {
+    const args = process.argv.slice(2);
+    // Check for options
+    const showAll = args.includes('-a');
+    const onePerLine = args.includes('-1');
+    //remove options from args 
+    const directories = args.filter(arg => arg !== '-a' && arg !== '-1');
+
+    // If no directory is specified, list the current directory
+    if(directories.length === 0) {
+        listDirectory(process.cwd(), showAll, onePerLine);
+        return;
+    }
+    //If a directory is specified, list that directory
+    directories.forEach((arg, index) => {
+        try {
+            const stats = fs.statSync(arg);
+            if(stats.isDirectory()) {
+                //Print header if multiple directories are listed
+                if(directories.length > 1) console.log(`${arg}:`);
+                
+                listDirectory(arg, showAll, onePerLine);
+                //add a blank line between directory listings if there are multiple directories
+                if(directories.length > 1 && index < directories.length - 1) console.log('');
+            } else{
+                console.log(arg);// single file
+            }
+        } catch (error) {
+            console.error(`Error accessing ${arg}: ${error.message}`);
+        }
+    });
+}
+main();
\ No newline at end of file
diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
new file mode 100755
index 000000000..58de824fc
--- /dev/null
+++ b/implement-shell-tools/wc/wc.js
@@ -0,0 +1,71 @@
+#!/usr/bin/env node
+const fs = require('node:fs');
+// Function to count lines, words, and bytes in a file
+function countFileContent(content) {
+    const lines = content.split('\n').length; // Count lines by splitting on newline characters
+    const words = content.trim().split(/\s+/).filter(Boolean).length; // Split by whitespace and filter out empty strings
+    const bytes = Buffer.byteLength(content, 'utf8');
+    return { lines, words, bytes };
+}
+
+//print counts in the format of wc according to options
+function printCounts(filePath, counts, options) {
+    const parts = [];
+    if(options.line) parts.push(counts.lines);
+    if(options.word) parts.push(counts.words);
+    if(options.byte) parts.push(counts.bytes);
+//if no specific count options are provided, print all counts
+    if(!options.line && !options.word && !options.byte) {
+    //default is to print all counts
+        parts.push(counts.lines, counts.words, counts.bytes);
+    }
+    console.log(parts.join('\t'),filePath);
+}
+
+function main() {
+    const args = process.argv.slice(2);
+    const options = {
+        line: false,
+        word: false,
+        byte: false,
+    };
+
+    //Separate options from file paths
+    const files = [];
+    args.forEach((arg) => {
+        if(arg === '-l') options.line = true;
+        else if(arg === '-w') options.word = true;
+        else if(arg === '-c') options.byte = true;
+        else files.push(arg);
+    });
+
+    if(files.length === 0) {
+        console.error('No files specified');
+        process.exit(1);
+    }
+
+    let totalCounts = { lines: 0, words: 0, bytes: 0 };
+    const multipleFiles = files.length > 1;
+    
+    files.forEach(file => {
+        try {
+            const content = fs.readFileSync(file, 'utf-8');
+            const counts = countFileContent(content);
+
+            // Sum counts for total if multiple files
+            totalCounts.lines += counts.lines;
+            totalCounts.words += counts.words;
+            totalCounts.bytes += counts.bytes;
+
+            printCounts(file, counts, options);
+        } catch (error) {
+            console.error(`Error reading file ${file}: ${error.message}`);
+        }
+    });
+    
+    // If multiple files, print total counts
+    if(multipleFiles) {
+        printCounts('total', totalCounts, options);
+    }
+}
+main();
\ No newline at end of file

From 972ae2b337192a9009f505f5895ee10a48191181 Mon Sep 17 00:00:00 2001
From: Ebrahim Beiaty <ebrahimbeiaty@gmail.com>
Date: Mon, 16 Mar 2026 12:39:23 +0000
Subject: [PATCH 2/4] applied the feedback

---
 implement-shell-tools/cat/cat.js | 106 +++++++++++++----------------
 implement-shell-tools/ls/ls.js   |  86 ++++++++++++------------
 implement-shell-tools/wc/wc.js   | 110 ++++++++++++++++---------------
 3 files changed, 144 insertions(+), 158 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index 2bdbfc039..0c70bc945 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -1,76 +1,60 @@
 #!/usr/bin/env node
-const fs = require('fs');
-const path = require('path');
-
+const fs = require("node:fs");
 //shared line counter across all files(matches cat -n)
 let globalLineCounter = 1;
 
 function printFile(filePath, options) {
-    try {
-        const content = fs.readFileSync(filePath, 'utf-8');
-        const lines = content.split('\n');
+  try {
+    const content = fs.readFileSync(filePath, "utf-8");
+    const lines = content.split("\n");
+
+    lines.forEach((line) => {
+      let prefix = "";
+
+      if (options.numberMode === "non-empty") {
+        //-b option: number non-empty lines
+        if (line.trim() !== "") {
+          prefix = `${String(globalLineCounter).padStart(6)}\t`;
+          globalLineCounter++;
+        }
+      } else if (options.numberMode === "all") {
+        prefix = `${String(globalLineCounter).padStart(6)}\t`;
+        globalLineCounter++;
+      }
 
-        lines.forEach((line) => {
-            if(options.numberNonEmpty) {
-                //-b option: number non-empty lines
-                if(line.trim()) {
-                    process.stdout.write(
-                        `${String(globalLineCounter).padStart(6)}\t${line}\n`
-                    );
-                    globalLineCounter++;
-                } else {
-                    process.stdout.write('\n');
-                }
-            } else if(options.numberAll) {
-                //-n option: number all lines
-                process.stdout.write(
-                    `${String(globalLineCounter).padStart(6)}\t${line}\n`
-                );
-                globalLineCounter++;
-            } else {
-                //default: just print the line
-                process.stdout.write(line + '\n');
-            }
+      process.stdout.write(`${prefix}${line}\n`);
     });
-
-    } catch (error) {
-        console.error(`Error reading file ${filePath}: ${error.message}`);
-    }
+  } catch (error) {
+    console.error(`cat: ${filePath}: ${error.message}`);
+  }
 }
 
 function main() {
-    const args = process.argv.slice(2);
-    const options = {
-        numberNonEmpty: false,
-        numberAll: false,
-    };
-    const filePatterns = [];
-
-    args.forEach((arg) => {
-        if(arg === '-n') {
-            options.numberAll = true;
-        } else if(arg === '-b') {
-            options.numberNonEmpty = true;
-        } else {
-            filePatterns.push(arg);
-        }
-    });
-    // -b takes precedence over -n
-    if(options.numberNonEmpty) {
-        options.numberAll = false;
-    }
-
-    if(filePatterns.length === 0) {
-        console.log("cat: missing file operand");
-        process.exit(1);
+  const args = process.argv.slice(2);
+
+  const options = {
+    numberMode: "off",
+  };
+
+  const files = [];
+  args.forEach((arg) => {
+    if (arg === "-n") {
+      options.numberMode = "all";
+    } else if (arg === "-b") {
+      options.numberMode = "non-empty";
+    } else {
+      files.push(arg);
     }
+  });
 
-    const files = filePatterns;
+  if (files.length === 0) {
+    console.log("cat: missing file operand");
+    process.exit(1);
+  }
 
-    files.forEach((file) => {
-        const resolvedPath = path.resolve(process.cwd(), file);
-        printFile(resolvedPath, options);
-    });
-    }
+  files.forEach((file) => {
+    printFile(file, options);
+  });
+}
 
 main();
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 7ba9c99cb..0cd8152b8 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -1,52 +1,52 @@
 #!/usr/bin/env node
-const fs = require('node:fs');
-const path = require('node:path');
-
+const fs = require("node:fs");
 function listDirectory(dirPath, showAll, onePerLine) {
-    try {
-        const entries = fs.readdirSync(dirPath, { withFileTypes: true });
-        const filtered = entries.filter((entry) => showAll || !entry.name.startsWith('.'));
+  try {
+    const entries = fs.readdirSync(dirPath, { withFileTypes: true });
+    const filtered = entries.filter(
+      (entry) => showAll || !entry.name.startsWith("."),
+    );
 
-        if(onePerLine) {
-            filtered.forEach(entry => console.log(entry.name));
-        } else {
-            const names = filtered.map(entry => entry.name);
-            console.log(names.join('  '));
-        }
-        } catch (error) {
-        console.error(`Error reading directory ${dirPath}: ${error.message}`);
+    if (onePerLine) {
+      filtered.forEach((entry) => console.log(entry.name));
+    } else {
+      const names = filtered.map((entry) => entry.name);
+      console.log(names.join("  "));
     }
+  } catch (error) {
+    console.error(`Error reading directory ${dirPath}: ${error.message}`);
+  }
 }
 function main() {
-    const args = process.argv.slice(2);
-    // Check for options
-    const showAll = args.includes('-a');
-    const onePerLine = args.includes('-1');
-    //remove options from args 
-    const directories = args.filter(arg => arg !== '-a' && arg !== '-1');
+  const args = process.argv.slice(2);
+  // Check for options
+  const showAll = args.includes("-a");
+  const onePerLine = args.includes("-1");
+  //remove options from args
+  let directories = args.filter((arg) => arg !== "-a" && arg !== "-1");
+
+  // Default to current directory if no directories are specified
+  if (directories.length === 0) {
+    directories = [process.cwd()];
+  }
+  //If a directory is specified, list that directory
+  directories.forEach((arg, index) => {
+    try {
+      const stats = fs.statSync(arg);
 
-    // If no directory is specified, list the current directory
-    if(directories.length === 0) {
-        listDirectory(process.cwd(), showAll, onePerLine);
-        return;
+      if (stats.isDirectory()) {
+        //Print header if multiple directories are listed
+        if (directories.length > 1) console.log(`${arg}:`);
+        listDirectory(arg, showAll, onePerLine);
+        //add a blank line between directory listings if there are multiple directories
+        if (directories.length > 1 && index < directories.length - 1)
+          console.log("");
+      } else {
+        console.log(arg); // single file
+      }
+    } catch (error) {
+      console.error(`Error accessing ${arg}: ${error.message}`);
     }
-    //If a directory is specified, list that directory
-    directories.forEach((arg, index) => {
-        try {
-            const stats = fs.statSync(arg);
-            if(stats.isDirectory()) {
-                //Print header if multiple directories are listed
-                if(directories.length > 1) console.log(`${arg}:`);
-                
-                listDirectory(arg, showAll, onePerLine);
-                //add a blank line between directory listings if there are multiple directories
-                if(directories.length > 1 && index < directories.length - 1) console.log('');
-            } else{
-                console.log(arg);// single file
-            }
-        } catch (error) {
-            console.error(`Error accessing ${arg}: ${error.message}`);
-        }
-    });
+  });
 }
-main();
\ No newline at end of file
+main();
diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
index 58de824fc..8462286e5 100755
--- a/implement-shell-tools/wc/wc.js
+++ b/implement-shell-tools/wc/wc.js
@@ -1,71 +1,73 @@
 #!/usr/bin/env node
-const fs = require('node:fs');
+const fs = require("node:fs");
 // Function to count lines, words, and bytes in a file
 function countFileContent(content) {
-    const lines = content.split('\n').length; // Count lines by splitting on newline characters
-    const words = content.trim().split(/\s+/).filter(Boolean).length; // Split by whitespace and filter out empty strings
-    const bytes = Buffer.byteLength(content, 'utf8');
-    return { lines, words, bytes };
+  const lines = content.split("\n").length; // Count lines by splitting on newline characters
+  const words = content.trim().split(/\s+/).filter(Boolean).length; // Split by whitespace and filter out empty strings
+  const bytes = Buffer.byteLength(content, "utf8");
+  return { lines, words, bytes };
 }
 
 //print counts in the format of wc according to options
 function printCounts(filePath, counts, options) {
-    const parts = [];
-    if(options.line) parts.push(counts.lines);
-    if(options.word) parts.push(counts.words);
-    if(options.byte) parts.push(counts.bytes);
-//if no specific count options are provided, print all counts
-    if(!options.line && !options.word && !options.byte) {
-    //default is to print all counts
-        parts.push(counts.lines, counts.words, counts.bytes);
-    }
-    console.log(parts.join('\t'),filePath);
+  const parts = [];
+  if (options.line) parts.push(counts.lines);
+  if (options.word) parts.push(counts.words);
+  if (options.byte) parts.push(counts.bytes);
+
+  console.log(parts.join("\t"), filePath);
 }
 
 function main() {
-    const args = process.argv.slice(2);
-    const options = {
-        line: false,
-        word: false,
-        byte: false,
-    };
+  const args = process.argv.slice(2);
+  const options = {
+    line: false,
+    word: false,
+    byte: false,
+  };
 
-    //Separate options from file paths
-    const files = [];
-    args.forEach((arg) => {
-        if(arg === '-l') options.line = true;
-        else if(arg === '-w') options.word = true;
-        else if(arg === '-c') options.byte = true;
-        else files.push(arg);
-    });
+  //Separate options from file paths
+  const files = [];
+  args.forEach((arg) => {
+    if (arg === "-l") options.line = true;
+    else if (arg === "-w") options.word = true;
+    else if (arg === "-c") options.byte = true;
+    else files.push(arg);
+  });
 
-    if(files.length === 0) {
-        console.error('No files specified');
-        process.exit(1);
-    }
+  if (files.length === 0) {
+    console.error("No files specified");
+    process.exit(1);
+  }
+  //If no specific count options are provided, default to all counts (lines, words, bytes)
+  if (!options.line && !options.word && !options.byte) {
+    options.line = true;
+    options.word = true;
+    options.byte = true;
+  }
 
-    let totalCounts = { lines: 0, words: 0, bytes: 0 };
-    const multipleFiles = files.length > 1;
-    
-    files.forEach(file => {
-        try {
-            const content = fs.readFileSync(file, 'utf-8');
-            const counts = countFileContent(content);
+  let totalCounts = { lines: 0, words: 0, bytes: 0 };
+  const multipleFiles = files.length > 1;
 
-            // Sum counts for total if multiple files
-            totalCounts.lines += counts.lines;
-            totalCounts.words += counts.words;
-            totalCounts.bytes += counts.bytes;
+  files.forEach((file) => {
+    try {
+      const content = fs.readFileSync(file, "utf-8");
+      const counts = countFileContent(content);
 
-            printCounts(file, counts, options);
-        } catch (error) {
-            console.error(`Error reading file ${file}: ${error.message}`);
-        }
-    });
-    
-    // If multiple files, print total counts
-    if(multipleFiles) {
-        printCounts('total', totalCounts, options);
+      // Sum counts for total if multiple files
+      totalCounts.lines += counts.lines;
+      totalCounts.words += counts.words;
+      totalCounts.bytes += counts.bytes;
+
+      printCounts(file, counts, options);
+    } catch (error) {
+      console.error(`Error reading file ${file}: ${error.message}`);
     }
+  });
+
+  // If multiple files, print total counts
+  if (multipleFiles) {
+    printCounts("total", totalCounts, options);
+  }
 }
-main();
\ No newline at end of file
+main();

From 09cde630adba902a249831529bdbcb96168b680b Mon Sep 17 00:00:00 2001
From: Ebrahim Beiaty <ebrahimbeiaty@gmail.com>
Date: Mon, 16 Mar 2026 13:47:04 +0000
Subject: [PATCH 3/4] applied the new feedbacks

---
 implement-shell-tools/wc/wc.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
index 8462286e5..1f7623f02 100755
--- a/implement-shell-tools/wc/wc.js
+++ b/implement-shell-tools/wc/wc.js
@@ -62,6 +62,7 @@ function main() {
       printCounts(file, counts, options);
     } catch (error) {
       console.error(`Error reading file ${file}: ${error.message}`);
+      process.exitCode = 1;
     }
   });
 

From 643fefa50470b98355b672c90e6074ec797c6a9d Mon Sep 17 00:00:00 2001
From: Ebrahim Beiaty <ebrahimbeiaty@gmail.com>
Date: Mon, 16 Mar 2026 13:47:29 +0000
Subject: [PATCH 4/4] applied the new feedbacks

---
 implement-shell-tools/cat/cat.js | 12 +++++-------
 implement-shell-tools/ls/ls.js   | 13 +++++++++----
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index 0c70bc945..052ba794b 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -11,16 +11,14 @@ function printFile(filePath, options) {
     lines.forEach((line) => {
       let prefix = "";
 
-      if (options.numberMode === "non-empty") {
-        //-b option: number non-empty lines
-        if (line.trim() !== "") {
+      const shouldNumber = 
+        options.numberMode === "all" ||
+        (options.numberMode === "non-empty" && line.trim() !== "");
+
+        if (shouldNumber) {
           prefix = `${String(globalLineCounter).padStart(6)}\t`;
           globalLineCounter++;
         }
-      } else if (options.numberMode === "all") {
-        prefix = `${String(globalLineCounter).padStart(6)}\t`;
-        globalLineCounter++;
-      }
 
       process.stdout.write(`${prefix}${line}\n`);
     });
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 0cd8152b8..c4b5e88b7 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -15,6 +15,7 @@ function listDirectory(dirPath, showAll, onePerLine) {
     }
   } catch (error) {
     console.error(`Error reading directory ${dirPath}: ${error.message}`);
+    process.exitCode = 1;
   }
 }
 function main() {
@@ -29,23 +30,27 @@ function main() {
   if (directories.length === 0) {
     directories = [process.cwd()];
   }
-  //If a directory is specified, list that directory
   directories.forEach((arg, index) => {
     try {
       const stats = fs.statSync(arg);
 
       if (stats.isDirectory()) {
         //Print header if multiple directories are listed
-        if (directories.length > 1) console.log(`${arg}:`);
+        if (directories.length > 1) {
+          console.log(`${arg}:`)
+        };
         listDirectory(arg, showAll, onePerLine);
         //add a blank line between directory listings if there are multiple directories
-        if (directories.length > 1 && index < directories.length - 1)
-          console.log("");
+        if (directories.length > 1 && index < directories.length - 1){
+          console.log(""); 
+        }
+          
       } else {
         console.log(arg); // single file
       }
     } catch (error) {
       console.error(`Error accessing ${arg}: ${error.message}`);
+      process.exitCode = 1;
     }
   });
 }