if ($protected) {
    local $SIG{INT} = 'IGNORE';
    precious();     # no interrupts during this function
}                   # previous handler (if any) restored

##</code><code>##

my @foo = (0..9);
print "[1] ", join('|', @foo), "\n";
local $foo[3] = 100;
print "[2] ", join('|', @foo), "\n";