RE: Is this best for multiline parsing?

While I think this is interesting, (I believe Randal Schwartz did a column
on doing something similer,) it seems to me that MIME::Parser already has
the functionality that you want. Perhaps you should look there?

Yves

> -----Original Message-----
> From: Chris Wilkes [mailto:[email protected]]
> Sent: 2002/02/19 11:11
> To: [email protected]
> Subject: Is this best for multiline parsing?
> 
> 
> Hello,
> 
>   I'm working on Mail::Audit so that I can pull out file attachment
> names from it.  To do so requires that you look at the headers for a
> "boundary" marker to figure out what seperates different attachments.
>   This is my first attempt at using RecDescent and would like 
> to know if
> this looks like the best way to do it or if someone would offer some
> style tips.
>   My main inspiration in this script was Damian's post of how 
> to parse a
> command seperated over multiple lines.  Except that one was a little
> easier than this as it had a line continuation marker at the end.
> Looking through some mail headers they don't do this, rather just
> indenting the next line a couple of spaces.
>   My next question is how to continue on with the rest of the file.  I
> don't really care what the file attachment is beyond its 
> listed filename
> and what lines it takes up in the ->body() reference to an 
> array returned
> by Mail::Audit.  I'm thinking about doing a while() loop till I get to
> the boundary marker and then sending the next non-blank lines through
> another RecDescent parse.  I don't want to have to tell RecDescent to
> look through thousands of lines of a mail file when it is not needed.
>   I realize that most of this could be done without RecDescent but
> thought I would give it a try.  Maybe I'm a masochist :)
> 
> Chris
> 
> ----------cut----------cut----------cut----------cut----------
> #!/usr/bin/perl
>  
> use Data::Dumper;
> use Parse::RecDescent;
> use strict;
>  
> my ($result, $parser, $grammar, $header);
>  
> $header = getdata();
>  
> $grammar = join '', <DATA>;
> $parser = Parse::RecDescent->new($grammar)
>   or die "Bad grammar '$grammar'\n";
>  
> $result = $parser->headerinfo($header);
>  
> print Dumper($result);
>  
> sub getdata {
>   my $header = <<'EOF';
> Delivered-To: [email protected]
> Content-Type: Multipart/Mixed;
>   charset="iso-8859-1";
>   boundary="------------Boundary-00=_2YQQSZM4Z8EP8VA9F3K8"
> From: Joe Blow <[email protected]>
> EOF
>   return $header;
> }
>  
> __DATA__
>   headerinfo:
>     parameter(s)
>     {  my %return;
>        foreach (@{$item{parameter}}) {
>          push @{$return{$_->[0]}}, $_->[1];
>        }
>        { \%return } }
>   parameter: key ':' value
>       { [ $item{key}, $item{value} ] }
>   key:
>     /^([^:]+)/ { $1 }
>   value:
>     multiline_value | singleline_value
>     singleline_value:
>       /(.*)\n/ { $1 }
>     multiline_value:
>       /^(.*?)\s*\n(\s+.*\n)+/
>         { $item[-1] =~ s/^\s+/ /gm;
>           $item[-1] =~ s/\s*\n//gm;
>           { $item[-1] } }
>