bash/tests/varenv10.sub

#!/bin/bash
#
# various tests of unset when applied to variables at different local scopes

# function unsetting variable at previous local scope, uncovering global

inner()
{
    unset res
    echo ${FUNCNAME}: ${res-res unset}
    if [[ $1 == "set" ]]; then
        res[0]="X"
        res[1]="Y"
    fi
}

outer()
{
    local res=
    inner "$1"
    echo ${FUNCNAME}: "res: ${res[@]}"
}

echo main: ${res-unset}
outer set
echo main: after first call: ${res-unset}
outer dontset 
echo main: after second call: ${res-unset}

unset -f outer inner
unset res

# local scope, unset variable at the same scope as local declaration
func()
{
	typeset x=4

	unset x
	echo ${FUNCNAME}: ${x:-null or unset}
}

x=outside
func
echo after func: x = $x

unset -f func
unset x