open FILE, "<$file" || die "Oops $!\n";

##</code><code>##

print ("Hello World!\n");
close (FILE);

##</code><code>##

/foo/ ? $a += 1 : $a -= 1;
# parses as
(/foo/ ? $a += 1 : $a) -= 1;
# but
$a += /foo/ ? 1 : -1;
# will work as expected.

##</code><code>##

$_ = 'foo';

/foo/   ? print "Found foo\n" : print "No foo here\n";
(/foo/) ? print "Found foo\n" : print "No foo here\n";
print /foo/   ? "Found foo\n" : "No foo here\n";
print (/foo/) ? "Found foo\n" : "No foo here\n";