London | 26-SDC-Mar | Khilola Rustamova| Sprint 3 |implementing shell tools

.gitignore

@@ -1 +1,2 @@
 node_modules
+*/venv

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/my-cat.js

@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+
+const fs = require("fs");
+
+const args = process.argv.slice(2);
+
+let numberLines = false;
+let numberNonEmpty = false;
+let files = [];
+
+//Parse arguments
+for (const arg of args) {
+  if (arg === "-n") {
+    numberLines = true;
+  } else if (arg === "-b") {
+    numberNonEmpty = true;
+  } else {
+    files.push(arg);
+  }
+}
+
+//Process each files
+args.forEach((file) => {
+  const content = fs.readFileSync(file, "utf-8");
+  const lines = content.split(/\r?\n/);
+
+  let count = 1;
+
+  lines.forEach((line) => {
+    const shouldNumber = numberLines || (numberNonEmpty && line !== "");
+
+    if (shouldNumber) {
+      console.log(`${count} ${line}`);
+      count++;
+    } else {
+      console.log(line);
+    }
+  });
+});

implement-shell-tools/cat/my-cat.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+set -euo pipefail
+
+number_lines=false 
+number_non_empty=false
+
+# check for flags
+if [ "${1:-}" = "-n" ]; then 
+  number_lines=true
+  shift
+elif [ "${1:-}" = "-b" ]; then
+  number_non_empty=true
+  shift
+fi
+
+count=1
+
+# Loop through all files
+
+for file in "$@"
+do
+  while IFS= read -r line
+  do
+    if [ "$number_lines" = true ]; then
+    echo "$count $line"
+    count=$((count+1))
+
+    else if [ "$number_non_empty" = true ]; then
+      if [ -n "$line" ]; then
+        echo "$count $line"
+        count=$((count+1))
+      else
+        echo ""
+       fi
+
+     else
+       echo "$line"
+     fi   
+   fi
+  done < "$file" 
+done

implement-shell-tools/ls/my-ls.js

@@ -0,0 +1,59 @@
+#!/usr/bin/env node 
+
+const fs = require("node:fs");
+const path = require("node:path");
+
+function parseArgs(args) {
+  let showAll = false;
+  let targetDir = ".";
+
+  for (const arg of args) {
+    if (arg === "-a") {
+      showAll = true;
+    } else if (!arg.startsWith("-")) {
+      targetDir = arg;
+    }
+  }
+
+  return { showAll, targetDir };
+}
+
+function listDirectory(dirPath, showAll) {
+  let files = fs.readdirSync(dirPath);
+
+  let hidden = [];
+  let normal = files;
+
+  if (!showAll) {
+    normal = files.filter(file => !file.startsWith("."));
+  } else {
+    hidden = files.filter(file => file.startsWith("."));
+    normal = files.filter(file => !file.startsWith("."));
+
+  }
+
+  normal.sort();
+  hidden.sort();
+
+  let result = [];
+
+  if (showAll) {
+    result.push(".","..");
+  }
+  result.push (...normal, ...hidden);
+
+  return result; 
+
+}
+
+function main() {
+  const args = process.argv.slice(2);
+  const { showAll, targetDir } = parseArgs(args);
+
+  const files = listDirectory(targetDir, showAll);
+  console.log(files.join("\n"));
+}
+
+main();
+
+

implement-shell-tools/ls/my-ls.sh

@@ -0,0 +1,34 @@
+  #!/bin/bash
+ set -euo pipefail
+
+show_all=false
+
+# handle -a
+if [ "${1:-}" = "-a" ]; then
+  show_all=true
+  shift
+fi 
+
+# directory (default current)
+ dir="."
+
+ if [ "${1:-}" != "" ]; then
+   dir="$1"
+ fi 
+
+ #choose pattern
+ if [ "$show_all" = true ]; then 
+   files="$dir"/.*
+ else
+   files="$dir"/*
+ fi
+ # loop      
+ for file in $files
+ do 
+   name="$(basename "$file")"
+
+   if [ "$name" = "." ] || [ "$name" = ".." ]; then 
+   continue
+   fi
+   echo "$name"
+  done  

implement-shell-tools/wc/my-wc.js

@@ -0,0 +1,83 @@
+#!/usr/bin/env node
+
+const fs = require("node:fs");
+
+function countFile(filePath) {
+  const stats = fs.statSync(filePath);
+
+  if (!stats.isFile()) {
+    console.warn(`${filePath} is not a file, skipping`);
+    return null;
+  }
+  const content = fs.readFileSync(filePath, "utf8");
+
+  const lines = content.split("\n").length - 1;
+  const words = content.trim() ? content.trim().split(/\s+/).length : 0;
+  const chars = Buffer.byteLength(content, "utf8");
+
+  return { lines, words, chars };
+}
+
+function main() {
+  const args = process.argv.slice(2);
+
+  let flags = [];
+  let files = [];
+
+  // 1 Parse args
+  for (const arg of args) {
+    if (arg === "-l" || arg === "-w" || arg === "-c") {
+      flags.push(arg);
+    } else {
+      files.push(arg);
+    }
+  }
+
+  //2 Helper function that decides what to print
+
+  function formatOutput(counts, files) {
+    const parts = [];
+
+    // if no flags show everything
+    const showAll = flags.length === 0;
+
+    if (showAll || flags.includes("-l"))parts.push(counts.lines);
+    if (showAll || flags.includes("-w"))parts.push(counts.words);
+    if (showAll || flags.includes("-c"))parts.push(counts.chars);
+
+    parts.push(files);
+
+    return parts.join(" ");
+  }
+  // 3 totals
+  let totalLines = 0;
+  let totalWords = 0;
+  let totalChars = 0;
+
+
+  // 4 per-file output
+  for (const file of files) {
+    const counts = countFile(file);
+    if (!counts) continue;
+
+    totalLines += counts.lines;
+    totalWords += counts.words;
+    totalChars += counts.chars;
+
+    console.log(formatOutput(counts, files));
+  }
+  // 5 Total output (only if multiple files)
+  if (files.length > 1) {
+    const totalCounts = {
+      lines: totalLines,
+      words: totalWords,
+      chars: totalChars,
+    };
+    console.log(formatOutput(totalCounts,"total"));
+  }
+}
+
+main();
+
+
+

implement-shell-tools/wc/my-wc.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+
+set -euo pipefail
+
+flag="all"
+
+if [ "${1:-}" = "-l" ]; then 
+  flag="l"
+  shift
+elif [ "${1:-}" = "-w" ]; then
+  flag="w"
+  shift
+elif [ "${1:-}" = "-c" ]; then
+  flag="c"
+  shift  
+fi
+
+for file in "$@"
+do 
+  if [ -d "$file" ]; then
+    continue
+  fi
+
+   lines=0
+   words=0
+   chars=0
+
+   while IFS= read -r line 
+   do
+     lines=$((lines + 1))
+     words=$((words + $(echo "$line" | wc -w)))
+     chars=$((chars + ${#line} + 1))
+   done <"$file" 
+
+   if [ "$flag" = "l" ]; then
+    echo "$lines $file"
+   elif [ "$flag" = "w" ]; then
+    echo "$words $file"
+   elif [ "$flag" = "c" ]; then
+    echo "$chars $file"
+   else 
+    echo "$lines $words $chars $file" 
+   fi    
+done
+