Advanced Bash Scripting Techniques
Bash scripting is a fundamental skill for Linux system administrators. This guide covers advanced techniques for writing robust, maintainable scripts.
#!/bin/bash
set -euo pipefail
# -e: Exit on error
# -u: Exit on undefined variable
# -o pipefail: Exit on pipe failure
cleanup() {
echo "Cleaning up..."
rm -f /tmp/tempfile
}
trap cleanup EXIT
# Compare two files
diff <(sort file1.txt) <(sort file2.txt)
# Default values
${VAR:-default}
${VAR:=default}
${VAR:?error message}
- Always quote variables
- Use arrays for multiple values
- Validate input parameters
- Implement logging
- Write unit tests with bats
#!/bin/bash
set -euo pipefail
BACKUP_DIR="${BACKUP_DIR:-/backups}"
SOURCE_DIR="${1:?Usage: $0 <source_dir>}"
if [[ ! -d "$SOURCE_DIR" ]]; then
echo "Error: $SOURCE_DIR does not exist" >&2
exit 1
fi
tar -czf "$BACKUP_DIR/backup-$(date +%Y%m%d).tar.gz" "$SOURCE_DIR"
Advanced bash scripting techniques enable you to write more robust and maintainable automation scripts.
For Advanced Bash Scripting Techniques, define pre-deploy checks, rollout gates, and rollback triggers before release. Track p95 latency, error rate, and cost per request for at least 24 hours after deployment. If the trend regresses from baseline, revert quickly and document the decision in the runbook.
Keep the operating model simple under pressure: one owner per change, one decision channel, and clear stop conditions. Review alert quality regularly to remove noise and ensure on-call engineers can distinguish urgent failures from routine variance.
Repeatability is the goal. Convert successful interventions into standard operating procedures and version them in the repository so future responders can execute the same flow without ambiguity.
For Advanced Bash Scripting Techniques, define pre-deploy checks, rollout gates, and rollback triggers before release. Track p95 latency, error rate, and cost per request for at least 24 hours after deployment. If the trend regresses from baseline, revert quickly and document the decision in the runbook.
Keep the operating model simple under pressure: one owner per change, one decision channel, and clear stop conditions. Review alert quality regularly to remove noise and ensure on-call engineers can distinguish urgent failures from routine variance.
Repeatability is the goal. Convert successful interventions into standard operating procedures and version them in the repository so future responders can execute the same flow without ambiguity.
For Advanced Bash Scripting Techniques, define pre-deploy checks, rollout gates, and rollback triggers before release. Track p95 latency, error rate, and cost per request for at least 24 hours after deployment. If the trend regresses from baseline, revert quickly and document the decision in the runbook.
Keep the operating model simple under pressure: one owner per change, one decision channel, and clear stop conditions. Review alert quality regularly to remove noise and ensure on-call engineers can distinguish urgent failures from routine variance.
Repeatability is the goal. Convert successful interventions into standard operating procedures and version them in the repository so future responders can execute the same flow without ambiguity.
For Advanced Bash Scripting Techniques, define pre-deploy checks, rollout gates, and rollback triggers before release. Track p95 latency, error rate, and cost per request for at least 24 hours after deployment. If the trend regresses from baseline, revert quickly and document the decision in the runbook.
Keep the operating model simple under pressure: one owner per change, one decision channel, and clear stop conditions. Review alert quality regularly to remove noise and ensure on-call engineers can distinguish urgent failures from routine variance.
Repeatability is the goal. Convert successful interventions into standard operating procedures and version them in the repository so future responders can execute the same flow without ambiguity.