In order to write to a file first we need to open the file for writing
with the :w mode. If this is successful we get back a filehandler on which
we can use the regular output methods such as print(), say() or printf().
examples/files/write_file.p6
#!/usr/bin/env perl6
use v6;
my $filename = "temp.txt";
my $fh = open $filename, :w;
$fh.say("hello world");
$fh.close;
