From: Ken Hornstein Date: Mon, 2 Apr 2012 19:39:00 +0000 (-0400) Subject: Bring in replyfilter to the docs directory. X-Git-Url: http://git.marmaro.de/?a=commitdiff_plain;ds=sidebyside;h=523cfc19212197befa73fc59460e93c563b76c9b;p=mmh Bring in replyfilter to the docs directory. --- diff --git a/Makefile.am b/Makefile.am index d7972a0..dbb5ec8 100644 --- a/Makefile.am +++ b/Makefile.am @@ -168,7 +168,7 @@ dist_doc_DATA = COPYRIGHT VERSION docs/COMPLETION-BASH docs/COMPLETION-TCSH \ docs/MAIL.FILTERING docs/MAILING-LISTS docs/README-ATTACHMENTS \ docs/README-HOOKS docs/README-components docs/README.about \ docs/README.SASL docs/README.developers docs/README.manpages \ - docs/TODO + docs/TODO docs/replyfilter ## ## Our man pages diff --git a/docs/pending-release-notes b/docs/pending-release-notes index e91c7bf..a80ce41 100644 --- a/docs/pending-release-notes +++ b/docs/pending-release-notes @@ -60,3 +60,5 @@ Things to add to the release notes for the next full release: - Added support for readline editing and command/filename completion at the WhatNow? prompt - The hostable option of mts.conf is no longer needed and has been removed. +- A sample mhl filter for handling MIME content inside of mhl has been + placed in the doc directory as "replyfilter". diff --git a/docs/replyfilter b/docs/replyfilter new file mode 100755 index 0000000..de81f87 --- /dev/null +++ b/docs/replyfilter @@ -0,0 +1,637 @@ +#!/usr/bin/perl +# +# replyfilter - A reply filter for nmh +# +# The idea behind this program is that it will act as a format filter +# for nmh. It will try to extract out all text/plain parts and format +# them if necessary using a filter program. +# +# To use this program, configure nmh in the following way (nmh 1.5 or later): +# +# - Put the path to this program in your .mh_profile under formatproc: +# +# formatproc: replyfilter +# +# - Create a mhl reply filter that consists of the following line: +# +# body:nocomponent,format,nowrap,formatarg="%(trim{content-type})%(putstr)",formatarg="%(trim{content-transfer-encoding})%(putstr)",formatarg=">" +# +# To decode this a bit: +# +# body - Output the "body" component +# nocomponent - Don't output a component prefix (normally here we use a +# component prefix of ">" as a quote character, but we're +# going to have replyfilter do that). +# nowrap - Don't wrap lines if they exceed the column width +# formatarg - Arguments to fmtproc. The first argument is the value of +# the Content-type header; the second is the value of the +# Content-Transfer-Encoding header. The last "formatarg" +# is used as your quoting prefix. Replace it with whatever +# you want. +# + +use Mail::Field; +use MIME::Head; +use MIME::QuotedPrint; +use MIME::Base64; +use Encode; + +# +# The program we use to format "long" text +# + +$filterprogram = 'par'; + +# +# Our output character set. This script assumes a UTF-8 locale, but if you +# want to run under a different locale the change it here. +# + +$outcharset = 'utf-8'; + +# +# Maximum column width (used by the HTML converter and to decide if we need +# to invoke the filter program +# + +$maxcolwidth = 78; + +# +# Out HTML converter program & arguments +# + +@htmlconv = ('w3m', '-dump', '-cols', $maxcolwidth - 2, '-T', 'text/html', + '-O', $outcharset); + + +die "Usage: $0 Content-type content-transfer-encoding quote-prefix\n" + if $#ARGV != 2; + +if ($ARGV[0] ne "") { + $content_type = Mail::Field->new('Content-Type', $ARGV[0]); +} + +$encoding = $ARGV[1] eq "" ? '7bit' : lc($ARGV[1]); +$quoteprefix = $ARGV[2]; + +# +# Set up our output to be in our character set +# + +binmode(STDOUT, ":encoding($outcharset)"); + +# +# The simplest case: if we have a single type of text/plain, send it +# to our format subroutine. +# + +if ($ARGV[0] eq "" || $content_type->type eq 'text/plain') { + process_text(\*STDIN, $encoding, $content_type->charset); + exit 0; +} + +# +# Alright, here's what we need to do. +# +# Find any text/plain parts and decode them. Decode them via base64 or +# quoted-printable, and feed them to our formatting filter when appropriate. +# Put markers in the output for other content types. +# + +($type) = (split('/', $content_type->type)); + +if ($type eq 'multipart') { + + # + # For multipart messages we have to do a little extra. + # Eat the MIME prologue (everything up until the first boundary) + # + + $boundary = $content_type->boundary; + + if ($boundary eq '') { + print "No boundary in Content-Type header!\n"; + eat_part(\*STDIN); + exit 1; + } + + while () { + last if match_boundary($_, $boundary); + } + + if (eof(STDIN)) { + print "Unable to find boundary in message\n"; + exit 1; + } +} else { + undef $boundary; +} + +process_part(\*STDIN, $content_type->type, $encoding, $content_type->charset, + $boundary); + +if ($boundary) { + # + # Eat the MIME eplilog + # + eat_part(\*STDIN); +} + +exit 0; + +# +# Handled encoded text. I think we can assume if the encoding is q-p +# or base64 to feed it into a formatting filter. +# + +sub process_text (*$$;$) +{ + my ($input, $encoding, $charset, $boundary) = @_; + my $text, $filterpid, $prefixpid, $finread, $finwrite; + my $foutread, $foutwrite, $decoder, $ret, $filterflag; + my @text = ( '' ), $maxline = 0; + + # + # In the simple case, just spit out the text prefixed by the + # quote character + # + + if ($encoding eq '7bit' || $encoding ne '8bit') { + while (<$input>) { + $ret = match_boundary($_, $boundary); + if (defined $ret) { + return $ret; + } + print $quoteprefix, $_; + } + return 'EOF'; + } else { + $decoder = find_decoder($encoding); + if (! defined $decoder) { + return 'EOF'; + } + } + + # + # Okay, assume that the encoding will make it so that we MIGHT need + # to filter it. Read it in; if it's too long, filter it. + # + + while (<$input>) { + my $line, $len; + + last if ($ret = match_boundary($_, $boundary)); + + $line = decode($charset, &$decoder($_)); + + if (substr($text[$#text], -1, 1) eq "\n") { + push @text, $line; + } else { + $text[$#text] .= $line; + } + if (($len = length($text[$#text])) > $maxline) { + $maxline = $len; + } + } + + if (! defined $ret) { + $ret = 'EOF'; + } + + if ($maxline <= $maxcolwidth) { + # + # These are short enough; just output it now as-is + # + print STDOUT @text; + return $ret; + } + + # + # We fork a copy of ourselves to read the output from the filter + # program and prefix the quote character. + # + + pipe($finread, $finwrite) || die "pipe() failed: $!\n"; + pipe($foutread, $foutwrite) || die "pipe() (second) failed: $!\n"; + + binmode($finread, ":encoding($outcharset)"); + binmode($finread, ":encoding($outcharset)"); + binmode($foutread, ":encoding($outcharset)"); + binmode($foutwrite, ":encoding($outcharset)"); + + if ($filterpid = fork) { + # + # Close the pipes in the parent that we're not using + # + + close($finread); + close($foutwrite); + } elsif (defined $filterpid) { + # + # Close our ununsed filehandles + # + + close($finwrite); + close($foutread); + + # + # Dup() down the filehandles to standard input and output + # + + open(STDIN, "<&", $finread) || + die "dup(filterin) failed: $!\n"; + open(STDOUT, ">&", $foutwrite) || + die "dup(filterout) failed: $!\n"; + + # + # Close our copies. + # + + close($finread); + close($foutwrite); + + # + # Exec our filter + # + + exec $filterprogram || + die "Unable to exec $filterprogram: $!\n"; + } else { + die "Fork for $filterprogram failed: $!\n"; + } + + # + # Fork our output handler. + # + + if ($prefixpid = fork) { + # + # We don't need these anymore + # + close($foutread); + + } elsif (defined $prefixpid) { + # + # Read from foutwrite, and output (with prefix) to stdout + # + + close($finwrite); + + while (<$foutread>) { + print STDOUT $quoteprefix, $_; + } + + exit 0; + } + + # + # Send our input to the filter program + # + + print $finwrite @text; + + close($finwrite); + waitpid $filterpid, 0; + warn "Filter process exited with ", ($? >> 8), "\n" if $?; + waitpid $prefixpid, 0; + warn "Pipe reader process exited with ", ($? >> 8), "\n" if $?; + + return $ret; +} + +# +# Filter HTML through a converter program +# + +sub process_html (*$$;$) +{ + my ($input, $encoding, $charset, $boundary) = @_; + my $filterpid, $prefixpid, $finread, $finwrite; + my $foutread, $foutwrite, $decoder, $ret; + + if (! defined($decoder = find_decoder($encoding))) { + return 'EOF'; + } + + # + # We fork a copy of ourselves to read the output from the filter + # program and prefix the quote character. + # + + pipe($finread, $finwrite) || die "pipe() failed: $!\n"; + pipe($foutread, $foutwrite) || die "pipe() (second) failed: $!\n"; + + binmode($finread, ":encoding($outcharset)"); + binmode($finread, ":encoding($outcharset)"); + binmode($foutread, ":encoding($outcharset)"); + binmode($foutwrite, ":encoding($outcharset)"); + + if ($filterpid = fork) { + # + # Close the pipes in the parent that we're not using + # + + close($finread); + close($foutwrite); + } elsif (defined $filterpid) { + # + # Close our ununsed filehandles + # + + close($finwrite); + close($foutread); + + # + # Dup() down the filehandles to standard input and output + # + + open(STDIN, "<&", $finread) || + die "dup(filterin) failed: $!\n"; + open(STDOUT, ">&", $foutwrite) || + die "dup(filterout) failed: $!\n"; + + # + # Close our copies. + # + + close($finread); + close($foutwrite); + + # + # Exec our converter + # + + exec (@htmlconv) || + die "Unable to exec $filterprogram: $!\n"; + } else { + die "Fork for $htmlconv[0] failed: $!\n"; + } + + # + # Fork our output handler. + # + + if ($prefixpid = fork) { + # + # We don't need these anymore + # + close($foutread); + + } elsif (defined $prefixpid) { + # + # Read from foutwrite, and output (with prefix) to stdout + # + + close($finwrite); + + while (<$foutread>) { + print STDOUT $quoteprefix, $_; + } + + exit 0; + } + + # + # Send our input to the filter program + # + + while (<$input>) { + last if ($ret = match_boundary($_, $boundary)); + print $finwrite (&$decoder($_)); + } + + if (! defined $ret) { + $ret = 'EOF'; + } + + close($finwrite); + waitpid $filterpid, 0; + warn "HTML converter process exited with ", scalar($? >> 8), "\n" if $?; + waitpid $prefixpid, 0; + warn "Pipe reader process exited with ", $? >> 8, "\n" if $?; + + return $ret; +} + +# +# Decide what to do, based on what kind of content it is. +# + +sub process_part (*$$$$;$) +{ + my ($input, $content_type, $encoding, $charset, $boundary, $name) = @_; + my ($type, $subtype) = (split('/', $content_type, -1), ''); + + if ($type eq 'text') { + # + # If this is a text part, right now we only deal with + # plain and HTML parts. + # + if ($subtype eq 'plain') { + return process_text($input, $encoding, $charset, + $boundary); + } elsif ($subtype eq 'html') { + return process_html($input, $encoding, $charset, + $boundary); + } else { + print ">>> $content_type content\n"; + return eat_part($input, $boundary); + } + } elsif ($type eq 'multipart') { + return process_multipart($input, $subtype, $boundary); + } else { + # + # Other types we're not sure what to do with right now + # Just put a marker in there + # + + print ">>> $content_type attachment"; + if (defined $name) { + print ", name=$name"; + } + print "\n"; + + return eat_part($input, $boundary); + } +} + +# +# Process a multipart message. +# +# When called, we should be right after the beginning of the first +# boundary marker. So we should be pointed at header lines which describe +# the content of this part +# + +sub process_multipart ($$$) +{ + my ($input, $subtype, $boundary) = @_; + my $altout; + + while (1) { + my $encoding, $type, $end, $name, $charset; + + # + # Use the Mail::Header package to read in any headers + # corresponding to this part + # + + my $head = Mail::Header->new($input, (MailFrom => 'IGNORE')); + + # + # Extract out any Content-Type, Content-Transfer-Encoding, and + # Content-Disposition headers + # + + my $ctype = Mail::Field->extract('Content-Type', $head); + my $cte = Mail::Field->extract('Content-Transfer-Encoding', + $head); + my $cdispo = Mail::Field->extract('Content-Disposition', $head); + + if (defined $ctype) { + $type = $ctype->type; + $charset = $ctype->charset; + } else { + $type = 'text/plain'; + $charset = 'us-ascii'; + } + + $encoding = defined $cte ? $cte->param('_') : '7bit'; + $name = defined $cdispo ? $cdispo->param('filename') : undef; + + # + # Special handling for multipart/alternative; pick + # the "first" one we can handle (which is usually + # text/plain) and silently eat the rest, but output a + # warning if we can't handle anything. + # + + if ($altout) { + $end = eat_part($input, $boundary); + } else { + my $subboundary = $boundary; + my $maintype = (split('/', $type))[0]; + + if ($maintype eq 'multipart') { + $subboundary = $ctype->boundary; + # + # Go until we find our beginning of this + # part + # + my $subend = eat_part($input, $subboundary); + + if ($subend ne 'EOP') { + print ">>> WARNING: malformed ", + "nested multipart\n"; + return $subend; + } + } + + $end = process_part($input, $type, $encoding, + $charset, $subboundary, $name); + + if ($subtype eq 'alternative' && ! defined $altout && + $type eq 'text/plain') { + $altout = 1; + } + + # + # Since we changed the semantics of $boundary + # above for nested multiparts, if we are + # handling a nested multipart then find the end + # of our current part + # + + if ($maintype eq 'multipart') { + $end = eat_part($input, $boundary); + } + + } + + if ($end eq 'EOM' || $end eq 'EOF') { + if ($subtype eq 'alternative' && !defined $altout) { + print ">>>multipart/alternative: no suitable ", + "parts\n"; + } + return $end; + } + } +} + +# +# "Eat" a MIME part; consume content until we hit the boundary or EOF +# + +sub eat_part ($$) +{ + my ($input, $boundary) = @_; + my $ret; + + # + # If we weren't given a boundary just eat input until EOF + # + + if (! defined $boundary) { + while (<$input>) { } + return 'EOF'; + } + + # + # Otherwise, consume data until we hit our boundary + # + + while (<$input>) { + if ($ret = match_boundary($_, $boundary)) { + return $ret; + } + } + + return 'EOF'; +} + +# +# Return the decoder subroutine to use +# + +sub find_decoder ($) +{ + my ($encoding) = @_; + + if ($encoding eq '7bit' || $encoding eq '8bit') { + return \&null_decoder; + } elsif ($encoding eq 'base64') { + return \&decode_base64; + } elsif ($encoding eq 'quoted-printable') { + return \&decode_qp; + } else { + warn "Unknown encoding: $encoding\n"; + return undef; + } +} + +sub null_decoder ($) +{ + my ($input) = @_; + + return $input; +} + +# +# Match a line against the boundary string +# + +sub match_boundary($$) +{ + my ($_, $boundary) = @_; + + if (substr($_, 0, 2) eq '--') { + s/[ \t\r\n]+\Z//; + if ($_ eq "--$boundary") { + return 'EOP'; + } elsif ($_ eq "--$boundary--") { + return 'EOM'; + } + } + + return undef; +}