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Bash scripting remains one of the most powerful yet underutilized tools in IT, cybersecurity, and DevOps. It can automate repetitive tasks, monitor systems, and handle log management efficiently. Below are practical examples and commands to leverage Bash effectively.
You Should Know: Essential Bash Scripts for Cyber & DevOps
1. Automating Log Cleaning
!/bin/bash
LOG_DIR="/var/log"
DAYS_TO_KEEP=7
find "$LOG_DIR" -type f -name ".log" -mtime +$DAYS_TO_KEEP -exec rm -f {} \;
echo "Old logs cleaned successfully."
Explanation: This script removes log files older than 7 days from /var/log.
2. Monitoring Disk Usage
!/bin/bash
THRESHOLD=80
CURRENT_USAGE=$(df / | grep / | awk '{print $5}' | sed 's/%//g')
if [ "$CURRENT_USAGE" -gt "$THRESHOLD" ]; then
echo "Warning: Disk usage is at ${CURRENT_USAGE}%!" | mail -s "Disk Alert" [email protected]
fi
Explanation: Sends an email alert if disk usage exceeds 80%.
3. Automated Backups with Compression
!/bin/bash BACKUP_DIR="/backups" SOURCE_DIR="/var/www" DATE=$(date +%Y-%m-%d) tar -czf "$BACKUP_DIR/backup_$DATE.tar.gz" "$SOURCE_DIR" echo "Backup completed: backup_$DATE.tar.gz"
Explanation: Creates a compressed backup of `/var/www` daily.
4. Detecting Unauthorized File Changes (Integrity Check)
!/bin/bash FILES="/etc/passwd /etc/shadow" CHECKSUM_FILE="/var/log/file_checksums" if [ ! -f "$CHECKSUM_FILE" ]; then sha256sum $FILES > "$CHECKSUM_FILE" else sha256sum -c "$CHECKSUM_FILE" fi
Explanation: Monitors critical system files for unauthorized changes.
5. Killing Suspicious Processes
!/bin/bash PROCESS="malicious_script" if pgrep -x "$PROCESS" > /dev/null; then pkill -9 "$PROCESS" echo "$PROCESS terminated." fi
Explanation: Detects and kills a malicious process.
What Undercode Say
Bash scripting is a foundational skill for IT professionals, cybersecurity experts, and DevOps engineers. While Python is better for complex tasks, Bash excels in quick automation, system monitoring, and log management. Mastering these scripts can significantly improve efficiency and security posture.
Expected Output:
- Logs cleaned automatically.
- Disk alerts sent via email.
- Regular backups stored in
/backups. - Critical file changes detected.
- Suspicious processes terminated.
Prediction
As automation grows, Bash scripting will remain essential for quick system tasks, while AI-driven scripting (e.g., GitHub Copilot) may assist in generating more complex scripts. However, understanding Bash fundamentals will always be valuable.
Relevant URLs:
References:
Reported By: Nagavamsi Bash – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
