Bash Scripting

Overview

Bash is the default shell on most Linux distributions and the primary scripting language for system administration, automation, and security tooling on Unix systems. Understanding Bash is essential for writing enumeration scripts, automating tool chains, parsing output, and building quick one-liners during engagements.

Topics

• Bash Script Writing — variables, control flow, functions, arrays, file operations, and script structure for security automation
• Useful One-Liners — practical one-liners for reconnaissance, enumeration, file operations, network tasks, and log analysis

Quick Reference

Bash basics:
  bash script.sh       — run a script
  chmod +x script.sh   — make executable
  ./script.sh          — run directly
  bash -x script.sh    — debug mode (trace execution)
  bash -n script.sh    — syntax check without executing

Shebang lines:
  #!/usr/bin/env bash  — portable (recommended)
  #!/bin/bash          — explicit path