#   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/>.
#
var=$'\01\02\03\177'

bar=${unset:-$var}
recho "$bar"
unset -v bar
bar=${unset:-"$var"}
recho "$bar"

foo=${parameter:=$var}

recho "$foo"
recho "$parameter"

unset -v foo parameter

foo=${parameter:="$var"}

recho "$foo"
recho "$parameter"

unset -v foo parameter

foo="${parameter:=$var}"

recho "$foo"
recho "$parameter"

unset -v foo parameter

recho ${parameter:=a\ b}
unset -v parameter

recho ${parameter:="a b"}
unset -v parameter

v='a b'

recho ${parameter:=$v}
unset -v parameter

recho ${parameter:="$v"}
unset -v parameter

# unsetting IFS here

set "  abc  " " def  ghi " "jkl "
unset -v IFS var
var=${var-$*}/${var-$*}
printf '[%s]\n' "$var"

unset -v var
: ${var=$*}
printf '[%s]\n' "$var"

unset -v var
: ${var:=$*/$*/${var-$*}}
printf '[%s]\n' "$var"