bash-expert

name	bash-expert
description	Write reliable shell commands and scripts

Follow these steps when writing or executing shell commands:

1. Always use set -e at the top of multi-line scripts so the script exits on the first error rather than silently continuing.

2. Quote all variables with double quotes: "$var" not $var. Unquoted variables break on spaces and special characters.

3. Capture stderr alongside stdout when you need full output: use command 2>&1 or check both streams separately.

4. Check exit codes explicitly for commands where failure matters but doesn't abort the script:

   if ! command; then
     echo "command failed" >&2
     exit 1
   fi
   

5. Use mktemp for temporary files rather than hard-coded paths like /tmp/foo. This avoids collisions between concurrent runs.

6. Prefer find . -name '*.ts' -print0 | xargs -0 over for f in $(find ...) when filenames may contain spaces.

7. Use || true to suppress errors for optional commands (e.g. rm -f file || true).

8. Limit output when running commands that may produce large output: pipe through head -n 100 or slice with tail -n 50.

9. Explain what a command does in a comment above it when it is non-obvious — especially for pipes and compound expressions.

10. Test destructive commands (rm, overwrite) with echo or --dry-run first if supported by the tool.