$ perl -e '
    my $insert = <<EOF;
line1
    line2
line3
EOF
    print "<pre>$insert</pre>";
'
<pre>line1
    line2
line3
</pre>

##</code><code>##

$ perl -e '
    chomp(my $insert = <<EOF);
line1
    line2
line3
EOF
    print "<pre>$insert</pre>";
'
<pre>line1
    line2
line3</pre>