shell-scripting-standards

Start with #!/usr/bin/env bash and set -euo pipefail to exit on errors, undefined variables, and pipe failures. Add a trap-based cleanup function for EXIT, INT, and TERM signals to remove temporary files and release locks.

Bats is a TAP-compliant testing framework for bash. Source your script in the setup function, then write @test blocks that call functions and assert on exit status and output. Use run to capture failures without aborting the test.

ShellCheck is a static analysis tool that detects over 300 classes of shell script bugs, such as unquoted variables (SC2086) and deprecated backticks (SC2006). Run it in CI with find . -name "*.sh" -exec shellcheck {} + and configure rules via a .shellcheckrc file.

Unquoted variables cause word splitting, so paths with spaces get treated as multiple arguments. Always quote variables like "$file" and iterate arrays with "${files[@]}" to preserve elements containing whitespace.

Detect the OS with uname -s and branch on differences, such as sed -i requiring an empty string argument on macOS. Use command -v instead of which, and avoid GNU-only flags when targeting BSD userland tools.

Avoid bash for scripts exceeding roughly 500 lines, complex data structure manipulation, or tasks requiring strong typing and error recovery. In those cases, a language like Python with proper exception handling is a better fit.