Ruby-list Tutorial 200~

p Math.sqrt(2) #=>1.4142135623730951
p Math::PI #=>3.141592653589793

=begin
trap "SIGURS1", 'print "foobar"'
kill "SIGURS1", $$
=end

proc = proc{print "foo\n"}
proc.call #=>foo

p self #=>main

proc2 = proc{print "$x changed ";
print "$x = ",$x,"\n"
}
trace_var (:$x){
proc2.call #=>$x changed $x = 5
}
$x = 5