# LInux-commands-to-use-in-shell-scripting LInux commands to use in shell scripting

File & Directory Automation

$ find /var/log -type f -name ".log" -mtime +7 -delete $ tar -czf logs_$(date +%F).tar.gz /var/log/.log $ rsync -avz /local/path/ user@remote:/backup/ $ for f in *.txt; do mv "$f" "${f%.txt}.bak"; done

System & Process Automation

$ systemctl is-active nginx || systemctl restart nginx $ sudo apt update -y && sudo apt upgrade -y $ free -m | awk '/Mem:/ {if ($4 < 100) system("sudo reboot")}'

Networking Automation

$ for h in host1 host2 host3; do ping -c1 $h && echo "$h OK" || echo " DOWN"; done $ curl -Is https:// example dot com | head -1 $ ping -c2 8 dot 8 dot 8 dot 8 || systemctl restart network

Security & Credential Automation

$ ssh-keygen -t rsa -b 4096 -f ~/.ssh/id_rsa -N "" $ ssh-copy-id user@host $ grep "Failed password" /var/log/auth.log | awk '{print $11}' | sort | uniq -c | sort -nr

DevOps & CI/CD Automation

$ git clone https://repo.git && cd repo && . build dot sh $ docker system prune -af $ kubectl get pods -A | grep -v Running $ kubectl rollout restart deployment myapp -n prod

Monitoring & Alerts

$ df -h | awk 'NR>1 && $5+0>90 {print $6 " is full"}' | mail -s "Disk Alert" $ pgrep nginx > /dev/null || systemctl restart nginxadmin at example dot com $ echo "$(date): $(uptime)" >> /var/log/health.log

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