Shell Script Best-Practice

starter-script.sh

#!/usr/bin/env bash

set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace
fi

if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then
    echo 'Usage: ./script.sh arg-one arg-two

This is an awesome bash script to make your life better.

'
    exit
fi

cd "$(dirname "$0")"

main() {
    echo do awesome stuff
}

main "$@"

starter-script_commented.sh

#!/usr/bin/env bash
# via https://sharats.me/posts/shell-script-best-practices/

set -o errexit      # when a command fails, bash exits instead of continuing with the rest of the script
set -o nounset      # make the script fail, when accessing an unset variable
set -o pipefail     # ensure that a pipeline command is treated as failed, even if one command in the pipeline fails
if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace   # enable debug mode, by running your script as TRACE=1 ./starter-script.sh
fi

if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then # Use [[ ]] for conditions, instead of [ ] and always add help
    echo 'Usage: ./script.sh arg-one arg-two

This is an awesome bash script to make your life better.

'
    exit
fi

cd "$(dirname "$0")" # Always quote variable accesses with double-quotes, change to the script’s directory 

main() {
    echo do awesome stuff
}

main "$@"