`set` - set or unset shell options and positional parameters

set [-euxo OPTION] [--] [ARG]...

Options you will use

-e, -o errexit: Exit on an untested non-zero status.
-u, -o nounset: Error on an unset variable.
-x, -o xtrace: Print each command before running it.
-o pipefail: A pipeline fails if ANY element fails, not just the last.
+OPTION: Turn the option back off.
-C: noclobber: > refuses to overwrite an existing file (use >| to force). +C turns it off.
-E: errtrace: the ERR trap also fires inside functions and subshells.

set -euo pipefail is the standard script header - but know its gaps: conditions, && / ||, and local x=$(cmd).

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