#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
IFS=''			# testing with only empty IFS

set -- this is a test

printf '|%s|\n' ${1+"$@"}
echo
printf '|%s|\n' "${1+$@}"
echo
printf '|%s|\n' "$@"
echo

printf '|%s|\n' ${1-"$@"}
printf '|%s|\n' "${1-$@}"

echo
: ${foo:="$@"}
printf '|%s|\n' "$foo"

unset foo
: "${foo:=$@}"
printf '|%s|\n' "$foo"

unset foo
printf '|%s|\n' ${foo-"$@"}
printf '|%s|\n' "${foo-$@}"