script template

do-stuff.sh

#!/usr/bin/env bash
# Usage:
#   Without trace, just run `./do-stuff.sh`
#   With trace, use `BASH_XTRACEFD=3 ./do-stuff 3> trace.txt`
# Requires bash 4.+
set -o pipefail
set -o nounset
set -o errexit

if [[ ${BASH_XTRACEFD:+x} ]]; then
  set -o xtrace
fi

if false; then
  cat /tmp/w00t > /dev/null
else
  cat /tmp/w11t > /dev/null
fi

If BASH_XTRACEFD is set, turns on xtrace and outputs trace to the given file descriptor. Otherwise, does not use xtrace.