$a = 10;

​

$b = q{a = $a};

print "Value of q{a = \$a} = $b\n";

​

$b = qq{a = $a};

print "Value of qq{a = \$a} = $b\n";

​

# unix command execution

$t = qx{date};

print "Value of qx{date} = $t\n";

​