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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Shell Scripting Basics</title>
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</head>
<body>
    <div class="presentation">
        <div class="slide-counter">
            <span id="current">1</span> / <span id="total">10</span>
        </div>

        <!-- Slide 1: Title -->
        <div class="slide active">
            <h1>🐚 Shell Scripting Basics</h1>
            <p style="font-size: 1.5em; margin-top: 40px;">Automate Your Tasks with Bash</p>
            <div style="margin-top: 60px;">
                <p><span class="emoji">📝</span> Write once, run many times</p>
                <p><span class="emoji">⚡</span> Automate repetitive tasks</p>
                <p><span class="emoji">🔧</span> Control your system with code</p>
            </div>
        </div>

        <!-- Slide 2: What is a Shell Script? -->
        <div class="slide">
            <h2>🤔 What is a Shell Script?</h2>
            <p>A shell script is a text file containing a series of commands that the shell executes line by line.</p>

            <div class="info-box">
                <p><strong>Think of it as a recipe:</strong></p>
                <p>Just like a recipe has steps to make a dish, a shell script has commands to complete a task!</p>
            </div>

            <h3>Why use shell scripts?</h3>
            <ul>
                <li>Automate repetitive tasks</li>
                <li>Save time and reduce errors</li>
                <li>Schedule tasks to run automatically</li>
                <li>Combine multiple commands into one</li>
            </ul>
        </div>

        <!-- Slide 3: Your First Script -->
        <div class="slide">
            <h2>✨ Your First Shell Script</h2>

            <h3>Step 1: Create the file</h3>
            <div class="code-box">
nano hello.sh
            </div>

            <h3>Step 2: Write the script</h3>
            <div class="code-box">
<span class="comment">#!/bin/bash</span>
<span class="comment"># This is my first shell script</span>

<span class="keyword">echo</span> <span class="string">"Hello, World!"</span>
<span class="keyword">echo</span> <span class="string">"Welcome to shell scripting!"</span>
            </div>

            <h3>Step 3: Make it executable</h3>
            <div class="code-box">
chmod +x hello.sh
            </div>

            <h3>Step 4: Run it</h3>
            <div class="code-box">
./hello.sh
            </div>
        </div>

        <!-- Slide 4: The Shebang -->
        <div class="slide">
            <h2>🎯 The Shebang Line</h2>

            <div class="code-box">
<span class="comment">#!/bin/bash</span>
            </div>

            <p>Every shell script starts with the <strong>shebang</strong> (#!)</p>

            <div class="info-box">
                <p><strong>What does it do?</strong></p>
                <p>It tells the system which interpreter to use to run the script.</p>
                <p><code>#!/bin/bash</code> means "use the Bash shell"</p>
            </div>

            <div class="warning-box">
                <p><span class="emoji">⚠️</span> <strong>Important:</strong> The shebang must be the very first line of your script!</p>
            </div>
        </div>

        <!-- Slide 5: Variables -->
        <div class="slide">
            <h2>📦 Variables</h2>
            <p>Variables store data that you can use later in your script.</p>

            <h3>Creating variables:</h3>
            <div class="code-box">
<span class="comment">#!/bin/bash</span>

<span class="comment"># No spaces around the = sign!</span>
name=<span class="string">"John"</span>
age=25
city=<span class="string">"New York"</span>

<span class="comment"># Using variables (with $)</span>
<span class="keyword">echo</span> <span class="string">"My name is $name"</span>
<span class="keyword">echo</span> <span class="string">"I am $age years old"</span>
<span class="keyword">echo</span> <span class="string">"I live in $city"</span>
            </div>

            <div class="warning-box">
                <p><span class="emoji">❌</span> Wrong: <code>name = "John"</code> (spaces)</p>
                <p><span class="emoji">✅</span> Correct: <code>name="John"</code> (no spaces)</p>
            </div>
        </div>

        <!-- Slide 6: User Input -->
        <div class="slide">
            <h2>💬 Getting User Input</h2>
            <p>Use the <code>read</code> command to get input from users.</p>

            <div class="code-box">
<span class="comment">#!/bin/bash</span>

<span class="keyword">echo</span> <span class="string">"What is your name?"</span>
<span class="keyword">read</span> username

<span class="keyword">echo</span> <span class="string">"What is your age?"</span>
<span class="keyword">read</span> age

<span class="keyword">echo</span> <span class="string">"Hello $username! You are $age years old."</span>
            </div>

            <h3>Reading with a prompt:</h3>
            <div class="code-box">
<span class="keyword">read</span> -p <span class="string">"Enter your name: "</span> name
<span class="keyword">echo</span> <span class="string">"Hi, $name!"</span>
            </div>
        </div>

        <!-- Slide 7: Conditionals (if-else) -->
        <div class="slide">
            <h2>🔀 Making Decisions (if-else)</h2>

            <div class="code-box">
<span class="comment">#!/bin/bash</span>

<span class="keyword">echo</span> <span class="string">"Enter a number:"</span>
<span class="keyword">read</span> number

<span class="keyword">if</span> [ $number -gt 10 ]; <span class="keyword">then</span>
    <span class="keyword">echo</span> <span class="string">"Number is greater than 10"</span>
<span class="keyword">elif</span> [ $number -eq 10 ]; <span class="keyword">then</span>
    <span class="keyword">echo</span> <span class="string">"Number is equal to 10"</span>
<span class="keyword">else</span>
    <span class="keyword">echo</span> <span class="string">"Number is less than 10"</span>
<span class="keyword">fi</span>
            </div>

            <h3>Comparison Operators:</h3>
            <table>
                <tr>
                    <th>Operator</th>
                    <th>Meaning</th>
                </tr>
                <tr>
                    <td>-eq</td>
                    <td>Equal to</td>
                </tr>
                <tr>
                    <td>-ne</td>
                    <td>Not equal to</td>
                </tr>
                <tr>
                    <td>-gt</td>
                    <td>Greater than</td>
                </tr>
                <tr>
                    <td>-lt</td>
                    <td>Less than</td>
                </tr>
            </table>
        </div>

        <!-- Slide 8: Loops -->
        <div class="slide">
            <h2>🔁 Loops</h2>

            <h3>For Loop:</h3>
            <div class="code-box">
<span class="comment">#!/bin/bash</span>

<span class="comment"># Print numbers 1 to 5</span>
<span class="keyword">for</span> i <span class="keyword">in</span> 1 2 3 4 5
<span class="keyword">do</span>
    <span class="keyword">echo</span> <span class="string">"Number: $i"</span>
<span class="keyword">done</span>
            </div>

            <h3>While Loop:</h3>
            <div class="code-box">
<span class="comment">#!/bin/bash</span>

counter=1
<span class="keyword">while</span> [ $counter -le 5 ]
<span class="keyword">do</span>
    <span class="keyword">echo</span> <span class="string">"Count: $counter"</span>
    counter=$((counter + 1))
<span class="keyword">done</span>
            </div>
        </div>

        <!-- Slide 9: Functions -->
        <div class="slide">
            <h2>🎪 Functions</h2>
            <p>Functions let you reuse code and keep your scripts organized.</p>

            <div class="code-box">
<span class="comment">#!/bin/bash</span>

<span class="comment"># Define a function</span>
greet() {
    <span class="keyword">echo</span> <span class="string">"Hello, $1!"</span>
    <span class="keyword">echo</span> <span class="string">"Welcome to shell scripting!"</span>
}

<span class="comment"># Call the function</span>
greet <span class="string">"Alice"</span>
greet <span class="string">"Bob"</span>
            </div>

            <div class="info-box">
                <p><strong>$1, $2, $3...</strong> are parameters passed to the function</p>
                <p><strong>$1</strong> = first parameter</p>
                <p><strong>$2</strong> = second parameter, and so on</p>
            </div>
        </div>

        <!-- Slide 10: Practical Example -->
        <div class="slide">
            <h2>🎯 Practical Example: Backup Script</h2>

            <div class="code-box">
<span class="comment">#!/bin/bash</span>

<span class="comment"># Simple backup script</span>

<span class="keyword">echo</span> <span class="string">"Starting backup..."</span>

<span class="comment"># Variables</span>
source_dir=<span class="string">"/home/user/documents"</span>
backup_dir=<span class="string">"/home/user/backup"</span>
date=$(date +%Y-%m-%d)

<span class="comment"># Create backup directory if it doesn't exist</span>
<span class="keyword">if</span> [ ! -d <span class="string">"$backup_dir"</span> ]; <span class="keyword">then</span>
    mkdir -p <span class="string">"$backup_dir"</span>
<span class="keyword">fi</span>

<span class="comment"># Create backup</span>
tar -czf <span class="string">"$backup_dir/backup-$date.tar.gz"</span> <span class="string">"$source_dir"</span>

<span class="keyword">echo</span> <span class="string">"Backup completed: backup-$date.tar.gz"</span>
            </div>

            <div class="info-box">
                <p><span class="emoji">💡</span> <strong>Tip:</strong> You can schedule this script to run automatically using cron!</p>
            </div>
        </div>

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