---
id:"kb-2026-00259"
title:"Shell Scripting (Bash)"
schema_type:"TechArticle"
category:"computer-science"
language:"en"
confidence:"high"
last_verified:"2026-05-22"
generation_method: "human_only"
ai_models:["claude-opus"]
derived_from_human_seed:true


known_gaps:
  - "Sources reconstructed during quality audit; primary source details were corrupted during batch generation"

completeness: 0.88
ai_citations:
  last_citation_check:"2026-05-22"
primary_sources:
- title: "ACM Digital Library"
    type: "repository"
    year: 2026
    url: "https://dl.acm.org/"
    institution: "ACM"
secondary_sources:
  - title: "ACM Digital Library"
    type: "repository"
    year: 2026
    url: "https://dl.acm.org/"
    institution: "ACM"
---

## TL;DR

Bash (Bourne Again Shell) is the default shell on most Linux distributions. Shell scripts automate tasks: file operations, process management, text processing. Variables, conditionals, loops, functions — a complete programming language for system administration.

## Core Explanation

Variables: `NAME='value'`, reference with `$NAME` or `${NAME}`. Conditionals: `if [ -f file ]; then ... fi`. Loops: `for i in *.txt; do ... done`. Input: `$1 $2 ...` (positional params), `$#` (count), `$@` (all). Exit codes: 0=success, non-zero=failure. `set -euo pipefail` for strict mode (exit on error, undefined variable, pipe failures). Shebang: `#!/bin/bash`.

## Further Reading

- [Bash Reference Manual](undefined)