Final Challenges

Put your bash scripting skills to the test with these comprehensive challenges. Each challenge combines multiple concepts you've learned.

Challenge 1: File Statistics

Create a script that analyzes a directory and reports statistics:

#!/bin/bash
# Challenge: Implement file_stats function

file_stats() {
    local dir="${1:-.}"

    echo "=== Directory Statistics: $dir ==="

    # TODO: Implement these
    # 1. Count total files
    # 2. Count total directories
    # 3. Find largest file
    # 4. Show file type distribution
}

Challenge 2: Text Processing Pipeline

Build a word frequency analyzer:

#!/bin/bash
# Analyze word frequency in a text file

analyze_words() {
    local file="$1"

    # Convert to lowercase, split words, count, sort
    cat "$file" | \
        tr '[:upper:]' '[:lower:]' | \
        tr -cs '[:alpha:]' '\n' | \
        sort | \
        uniq -c | \
        sort -rn | \
        head -10
}

Challenge 3: Configuration Parser

Parse and validate a config file:

#!/bin/bash
# Parse key=value config file

declare -A CONFIG

parse_config() {
    local file="$1"

    while IFS='=' read -r key value; do
        # Skip comments and empty lines
        [[ "$key" =~ ^#.*$ || -z "$key" ]] && continue

        # Trim whitespace
        key=$(echo "$key" | xargs)
        value=$(echo "$value" | xargs)

        CONFIG["$key"]="$value"
    done < "$file"
}

validate_config() {
    local required=("host" "port" "user")

    for key in "${required[@]}"; do
        if [[ ! -v CONFIG[$key] ]]; then
            echo "Missing required config: $key" >&2
            return 1
        fi
    done
    return 0
}

Challenge 4: Process Monitor

Monitor a process and restart if it dies:

#!/bin/bash
# Process watchdog

PROCESS_NAME="$1"
CHECK_INTERVAL=10
MAX_RESTARTS=3
RESTART_COUNT=0

start_process() {
    echo "Starting $PROCESS_NAME..."
    # Start your process here
    "$PROCESS_NAME" &
}

check_process() {
    pgrep -x "$PROCESS_NAME" > /dev/null
}

while true; do
    if ! check_process; then
        echo "Process $PROCESS_NAME not running!"

        if [ $RESTART_COUNT -ge $MAX_RESTARTS ]; then
            echo "Max restarts reached. Exiting."
            exit 1
        fi

        start_process
        RESTART_COUNT=$((RESTART_COUNT + 1))
    fi

    sleep $CHECK_INTERVAL
done

Challenge 5: Log Rotator

Implement log rotation:

#!/bin/bash
# Rotate log files

rotate_log() {
    local log_file="$1"
    local max_files="${2:-5}"
    local max_size="${3:-10485760}"  # 10MB

    [ -f "$log_file" ] || return

    # Check size
    local size=$(stat -f%z "$log_file" 2>/dev/null || stat -c%s "$log_file")
    [ "$size" -lt "$max_size" ] && return

    echo "Rotating $log_file..."

    # Rotate existing numbered logs
    for ((i=max_files-1; i>=1; i--)); do
        [ -f "${log_file}.$i" ] && mv "${log_file}.$i" "${log_file}.$((i+1))"
    done

    # Move current log
    mv "$log_file" "${log_file}.1"

    # Create new empty log
    touch "$log_file"

    # Remove oldest if over limit
    [ -f "${log_file}.$((max_files+1))" ] && rm "${log_file}.$((max_files+1))"
}

Challenge 6: Directory Sync

Sync two directories with change detection:

#!/bin/bash
# Simple directory sync

sync_dirs() {
    local src="$1"
    local dst="$2"

    # Find new or modified files
    find "$src" -type f | while read -r file; do
        rel_path="${file#$src/}"
        dst_file="$dst/$rel_path"

        # Check if needs sync
        if [ ! -f "$dst_file" ] || [ "$file" -nt "$dst_file" ]; then
            mkdir -p "$(dirname "$dst_file")"
            cp "$file" "$dst_file"
            echo "Synced: $rel_path"
        fi
    done
}

Challenge 7: Report Generator

Generate HTML reports from data:

#!/bin/bash
# Generate HTML report

generate_report() {
    local title="$1"
    local data_file="$2"

    cat << EOF
<!DOCTYPE html>
<html>
<head><title>$title</title></head>
<body>
<h1>$title</h1>
<table border="1">
<tr><th>Name</th><th>Value</th></tr>
EOF

    while IFS=',' read -r name value; do
        echo "<tr><td>$name</td><td>$value</td></tr>"
    done < "$data_file"

    cat << EOF
</table>
<p>Generated: $(date)</p>
</body>
</html>
EOF
}

# Usage: generate_report "Status Report" data.csv > report.html

Challenge 8: Interactive Menu System

Create a full-featured menu:

#!/bin/bash
# Interactive menu system

show_menu() {
    clear
    echo "================================"
    echo "    System Administration"
    echo "================================"
    echo "1. Show disk usage"
    echo "2. Show memory usage"
    echo "3. Show running processes"
    echo "4. Check network"
    echo "5. Exit"
    echo "================================"
}

while true; do
    show_menu
    read -p "Select option: " choice

    case $choice in
        1) df -h; read -p "Press Enter..." ;;
        2) free -h; read -p "Press Enter..." ;;
        3) ps aux | head -20; read -p "Press Enter..." ;;
        4) ping -c 3 google.com; read -p "Press Enter..." ;;
        5) echo "Goodbye!"; exit 0 ;;
        *) echo "Invalid option"; sleep 1 ;;
    esac
done

Final Project Ideas

System Dashboard: Real-time system monitoring script
Deployment Tool: Git-based deployment automation
Backup Manager: Full backup solution with rotation
Log Analyzer: Comprehensive log analysis tool
Service Monitor: Multi-service health checker

Congratulations!

You've completed the Interactive Bash Scripting course! You've learned:

Script fundamentals and execution
Variables, quoting, and data types
User input and argument handling
Conditionals and control flow
Loops and iteration
Functions and scope
String manipulation
Arrays (indexed and associative)
File processing
Error handling and debugging
Practical automation scripts

Continue practicing by automating tasks in your daily work. The best way to master bash is to use it regularly!

Key Takeaways

Combine multiple concepts for powerful scripts
Always handle errors gracefully
Test scripts thoroughly before production use
Comment your code for future reference
Keep scripts modular and reusable
Security matters - validate all input
Performance matters - optimize when needed