Learn shell scripting best practices for writing maintainable, secure, and efficient bash scripts.

Shell Scripting Best Practices: Writing Maintainable Scripts

Good shell scripts are maintainable and reliable. This guide covers best practices.

Script Header #

bash.bash

#!/bin/bash
set -euo pipefail  # Exit on error, undefined vars, pipe failures

# Script metadata
# Author: Your Name
# Description: Script purpose
# Version: 1.0

Error Handling #

bash.bash

# Exit on error
set -e

# Trap errors
trap 'echo "Error at line $LINENO"' ERR

# Cleanup on exit
trap 'rm -f /tmp/tempfile' EXIT

Input Validation #

bash.bash

# Check arguments
if [ $# -lt 2 ]; then
    echo "Usage: $0 <arg1> <arg2>"
    exit 1
fi

# Validate input
if [ ! -f "$1" ]; then
    echo "Error: $1 is not a file"
    exit 1
fi

Functions #

bash.bash

# Define functions
log() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $*"
}

check_dependencies() {
    local deps="curl jq"
    for dep in $deps; do
        if ! command -v "$dep" &> /dev/null; then
            echo "Error: $dep is required"
            exit 1
        fi
    done
}

Best Practices #

Use set -euo pipefail
Validate inputs
Use functions
Add comments
Handle errors
Use quotes for variables
Check return codes

Conclusion #

Write maintainable scripts by using proper error handling, input validation, and functions. Follow best practices for reliability.

For Shell Scripting Best Practices: Writing Maintainable Scripts, 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.