A template for seeding new Bash scripts.

hello.sh

#! /usr/bin/env bash
#
# A template for seeding new Bash scripts.
#
if [ -z "${BASH_VERSINFO[0]}" ] || [ ${BASH_VERSINFO[0]} -lt 4 ]
then
    echo "ERROR: Only tested on Bourne-Again SHell v4/v5."
    exit 1
fi >&2
set -e
shopt -s nullglob
printf -v now '%(%FT%T%z)T'

main() {
    foo "$@"
}
########################################################################

foo() {
    echo "$now: $@"
}

########################################################################
# poor man's __main__
return 2>/dev/null ||:

if [ "$(type -t "$1")" = "function" ]
then
    func="$1"
    shift 1
    $func "$@"
else
    set -x # debugging
    main "$@"
fi

exit 0