Bash Scripting Collection

A comprehensive collection of Bash scripts designed to teach shell scripting from beginner to advanced levels. This repository contains practical examples, real-world automation scripts, and best practices for Bash programming.

📁 Repository Structure

🔰 01-Basics/

12 fundamental scripts covering essential Bash concepts:

• Basic syntax and structure
• Variables and user input
• Control flow (if-else, case, loops)
• Functions and arrays
• File operations and math
• Command-line arguments

Perfect for: Complete beginners, programming students, quick reference

🚀 02-Advanced/

16 advanced scripts demonstrating real-world applications:

• System administration and monitoring
• File operations and network tools
• Database backup and automation
• Interactive user interfaces
• Data processing and formatting
• Algorithm implementations

Perfect for: System administrators, DevOps engineers, intermediate scripters

🎯 Learning Path

For Beginners

01-Basics/ → Complete all 12 scripts in order
↓
02-Advanced/ → Start with system monitoring scripts (01, 03, 04)
↓
02-Advanced/ → File operations (05, 06, 09)
↓
02-Advanced/ → User interfaces (12, 13, 14)

For Intermediate Users

01-Basics/ → Quick review of fundamentals
↓
02-Advanced/ → Focus on automation (01, 02, 10, 11, 16)
↓
02-Advanced/ → Network and monitoring tools (07, 08)
↓
02-Advanced/ → Algorithm challenges (02-1, 15)

📊 Scripts Summary

Category	Basic Scripts	Advanced Scripts	Total
Control Flow	if-else, case, loops	Interactive menus	6
System Admin	File operations	Log rotation, health checks, monitoring	8
Data Processing	Variables, arrays, math	Table formatting, algorithms	7
Automation	Functions, arguments	Backup, database, expect	5
Network	-	Ping sweep, web status	2
Total	12	16	28

🛠 Prerequisites

Basic Requirements

• Unix-like operating system (Linux, macOS, WSL on Windows)
• Bash shell (version 4.0+)
• Text editor (vim, nano, VS Code, etc.)
• Basic command line knowledge

For Advanced Scripts

# Package installations (Ubuntu/Debian)
sudo apt-get install rsync curl mysql-client expect

# Package installations (CentOS/RHEL)
sudo yum install rsync curl mysql expect

# Package installations (macOS with Homebrew)
brew install rsync curl mysql-client expect

🚀 Quick Start

1. Clone the repository:

   git clone <repository-url>
   cd bash

2. Make scripts executable:

   chmod +x 01-Basics/*.sh
   chmod +x 02-Advanced/*.sh

3. Start with basics:

   cd 01-Basics
   ./01_hello_world.sh

4. Progress to advanced:

   cd ../02-Advanced
   ./04_system_health_check.sh

📋 Script Categories Explained

🔰 Basic Scripts (01-Basics/)

Script	Concept	Use Case
01_hello_world.sh	Basic structure	Your first script
02_variables.sh	Variable usage	Data storage
03_user_input.sh	Interactive input	User interaction
04_if_else.sh	Conditional logic	Decision making
05_case_statement.sh	Multi-way branching	Menu systems
06_for_loop.sh	Iteration	Repetitive tasks
07_while_loop.sh	Conditional loops	Dynamic iteration
08_functions.sh	Code organization	Reusable code
09_arrays.sh	Data structures	Multiple values
10_file_operations.sh	File I/O	File manipulation
11_math_operations.sh	Arithmetic	Calculations
12_script_arguments.sh	Parameters	Command-line args

🚀 Advanced Scripts (02-Advanced/)

Category	Scripts	Description
System Admin	01_log_rotation.sh 03_process_monitor.sh 04_system_health_check.sh 09_disk_usage_report.sh	Log management, process monitoring, system status reporting
File Operations	02_backup_script.sh 05_bulk_rename_files.sh 06_find_large_files.sh 10_mysql_backup.sh	Backup solutions, bulk operations, file discovery
Network Tools	07_network_ping_sweep.sh 08_web_status_checker.sh	Network diagnostics, web monitoring
User Interface	12_interactive_menu.sh 13_simple_table_format.sh 14_complex_table_format.sh	Menu systems, data presentation
Algorithms	02-longest-asc-subarray.sh 15_min_nearest_zero.sh	Array processing, mathematical operations
Automation	11_github_repo_cloner.sh 16_expect_demo.sh	Development tools, interactive automation

💡 Key Learning Outcomes

After Completing 01-Basics/

• ✅ Understand Bash syntax and structure
• ✅ Work with variables and user input
• ✅ Implement control flow and loops
• ✅ Create and use functions
• ✅ Handle arrays and file operations
• ✅ Process command-line arguments

After Completing 02-Advanced/

• ✅ Automate system administration tasks
• ✅ Monitor system health and processes
• ✅ Create professional user interfaces
• ✅ Implement backup and recovery solutions
• ✅ Build network diagnostic tools
• ✅ Process complex data structures
• ✅ Apply advanced automation techniques

🔧 Best Practices Demonstrated

Code Quality

• Consistent shebang usage: #!/bin/bash
• Error handling: Safe file operations
• Input validation: Secure user input processing
• Resource management: Efficient system resource usage

Security

• Safe file operations: Proper quoting and path handling
• Input sanitization: Preventing injection attacks
• Permission awareness: Understanding security contexts
• Credential management: Secure handling of sensitive data

Performance

• Efficient algorithms: Optimized data processing
• Resource conservation: Memory and CPU efficient scripts
• Parallel processing: Background job management
• Scalable solutions: Scripts that handle varying data sizes

🛡️ Safety Guidelines

⚠️ Always follow these safety practices:

1. Test First: Run scripts in safe environments
2. Read Code: Understand what scripts do before execution
3. Backup Data: Protect important files before running file operations
4. Check Permissions: Ensure appropriate access levels
5. Validate Inputs: Never trust user input without validation
6. Monitor Resources: Watch system impact during execution

🤝 Contributing

This repository welcomes contributions! Areas for improvement:

• Additional algorithm implementations
• Platform-specific optimizations
• Enhanced error handling
• Performance improvements
• Documentation updates

📖 Additional Resources

Learning Materials

• Bash Manual
• ShellCheck - Script analysis tool
• Advanced Bash Scripting Guide

Development Tools

• Debugging: Use bash -x script.sh for execution tracing
• Validation: Use ShellCheck for code quality
• Testing: Create test cases for your scripts
• Documentation: Comment your code thoroughly

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🎯 Next Steps

1. Complete the basics: Master all scripts in 01-Basics/
2. Practice daily: Incorporate scripts into your workflow
3. Modify and experiment: Adapt scripts to your needs
4. Build complex solutions: Combine multiple concepts
5. Share knowledge: Teach others and contribute back

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Happy Scripting! 🎉

Remember: The best way to learn Bash is by doing. Start with the basics, experiment with modifications, and gradually work your way up to the advanced scripts. Each script builds upon previous concepts, creating a comprehensive learning experience.