$foo X= $bar;
# is short for:
$foo = $foo X $bar;

##</code><code>##

$foo += $bar;
# is short for:
$foo = $foo + $bar;

$foo ||= $bar;
# is short for:
$foo = $foo || $bar;

$foo .= $bar;
# is short for:
$foo = $foo . $bar;

$foo *= $bar;
# is short for:
$foo = $foo * $bar;

##</code><code>##

$OUTFH{$name} = $OUTFH{$name} || IO::File->new(">g:\\perl_scripts\\$name.log");
$FH           = $OUTFH{$name} or die $!;

##</code><code>##

my $result = $cache{$input} ||= my_function($input);