# Linux : Bash ##### Here Docs ([ref](https://www.gnu.org/software/bash/manual/bash.html#Here-Documents)) ```bash cat <<___HERE contents captured exactly as-is, including leading whitespace variables (like $PATH) will be interpolated terminating token must start at beginning of line, regardless of current code indentation ___HERE ``` ##### The `set` Builtin ([ref](https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html)) ```bash -e # exit on non-zero exit code # WARNING: grep returns 1 if there are no results -o pipefail # in pipelines, return first non-zero exit code instead of last exit code -u # exit on undefined variable reference -v # echo lines ``` Recommended for Bash scripts: ```bash set -o pipefail set -u ```