$ perl -MPath::Tiny -Mstrict -Mautodie -wE '
my $file = Path::Tiny->tempfile;
open my $FH, ">", $file;
print $FH "$_\n" for qw/foo bar baz/;
close $FH;
open my $FH2, "<", $file;
print "2: $_" while (<$FH2>);
close $FH2;
open my $FH3, "+>>", $file;
print "3: $_" while (<$FH3>);
print $FH3 "I was here";
close $FH3;
open my $FH4, "<", $file;
print "4: $_" while (<$FH4>);
close $FH4;
'

##</code><code>##

2: foo
2: bar
2: baz
4: foo
4: bar
4: baz
4: I was here