use warnings;
use strict;

open my $FH,">>","test.txt" or die ">>: $!";
my @file = <$FH>;
if (defined $file[0]){
	print "Open with >>: ",shift @file,"\n";
}
else {
	print "Open with >>: undef\n";
}
close $FH;

open my $IN,"+<","test.txt" or die "#<: $!n";
my @file_new = <$IN>;
if (defined $file_new[0]){
	print "Open with +<: ",shift @file_new,"\n";
}
else {
	print "Open with +<: undef\n";
}
close $IN;

##</code><code>##

Open with >>: undef
Open with +<: Test