remove_lines_from_file() {
        # $1=filename
        # $2=substring match indicating lines to remove (case sensitive)
        cat "$1" | grep -q "$2" && {
                fix_symlink_hack "$1"
                local _substr_sed
                _substr_sed=$(echo "$2" |  sed s/'\/'/'\\\/'/g)
                cat "$1" |  sed /"$_substr_sed"/d > "$1"
        }
}

uci_set() {
        local PACKAGE="$1"
        local CONFIG="$2"
        local OPTION="$3"
        local VALUE="$4"

        ( # spawn a subshell so you don't mess up the current environment
                config_load "$PACKAGE"
                config_get ORIGVAL "$CONFIG" "$OPTION"
                uci_load "$PACKAGE"
                config_get OLDVAL "$CONFIG" "$OPTION"
                if [ "$OLDVAL" != "$VALUE" ]; then
                        if [ -e "/tmp/.uci/$PACKAGE" ]; then
                                remove_lines_from_file "/tmp/.uci/$PACKAGE" "config_set '$CONFIG' '$OPTION' '$OLDVAL'"
                        fi
                        if [ "$ORIGVAL" != "$VALUE" ]; then
                                config_get type "$CONFIG" TYPE
                                [ -z "$type" ]
                        else
                                [ -e "/tmp/.uci/$PACKAGE" ] && [ "`cat "/tmp/.uci/$PACKAGE"`" = "" ] && {
                                        rm "/tmp/.uci/$PACKAGE"
                                }
                        fi
                fi
        ) || uci_add_update "$PACKAGE" "config_set '$CONFIG' '$OPTION' '$VALUE'"
}