使用 MIME::Entity 将 HTML 电子邮件转为纯文本

Question

I'm using a perl script to convert HTML mails to plain text.

The current code (for multipart mails) looks like this:

my $parser = new MIME::Parser;
my $entity = $parser->parse(\*STDIN) or die "parse failed\n";

for my $part ($entity->parts()) {
 if ($part->mime_type eq 'text/html') {
 my $bh = $part->bodyhandle;

 my $tree = HTML::TreeBuilder->new();
 $tree->utf8_mode();
 $tree->parse($bh->as_string);

 my $formatter = HTML::FormatText->new(leftmargin => 0, rightmargin => 72);
 my $txt = $formatter->format($tree);

 my $txtEntity=MIME::Entity->build(Data  => $txt,
                                 Type  => "text/plain",
                                 Encoding => "8bit"
                                 );

 $entity->add_part($txtEntity,0);
 }
}
$entity->print(\*STDOUT);

It works but it adds just adds the plain text part to the existing parts and doesn't replace the HTML part.
So I came up with this:

my $head = $entity->head;

my $txtEntity=MIME::Entity->build(Data  => $txt,
                               Type  => "text/plain",
                               Encoding => "8bit",
                               From    => $head->get('From',0),
                               To      => $head->get('To',0),
                               Subject => $head->get('Subject',0),
                               Cc => $head->get('Cc',0)
                               );

$txtEntity->print(\*STDOUT);

But that could remove some parts of the email header. Is there a function to replace the HTML body completely with the plain text one?

Thanks!

Answer 1

If you don't have a way to replace the body instead of adding a new part, this might be a job for the formail utility (part of procmail) which can generate a new email with the headers of the old email, replacing the things you want to replace (like the encoding and content-type headers).

Also, you might just try changing the encoding to text-plain. You will still see the HTML code, but it will not render and you will also see your plain/text addition, though I grant this is a poor solution.