Perl script to save an email attachment to disk

From unknown source, bless his perl skills. Change the TMPDIR path to where you want to save the attachments. I called it unmime, you are free to call it anything you want.

Things to watch out for:

Path to perl RTE.
Executable rights for script.


Define an alias in sendmail's /etc/aliases to call the script, e.g:
detach: |"/your/path/to/script/unmime"

Mailing to the alias will detach the file to your preferred directory. Remember to run "newaliases" after adding the alias.

Script below:

#!/usr/bin/perl
#
# Un-MIME regular message from stdin.
# Non-text version saved in directory ~/mail/MIME and proper indication is
# left in the dumped message. Text is otherwise dumped and deleted from there.
#
# Intended to be used with mailagent thanks to the following incantation rule:
#
# Mime-Version: /^\d/ { SAVE +mime; FEED ~/mail/unmime; RESYNC; REJECT };
#
# Options:
# -e: pass the quoted-printable decoder over the message and that's it.
# -x: translate chars not understood by some iso8859-1 fonts.
# -X: translate all accents to non-accentuated letters (plain ASCII).

($me = $0) =~ s|.*/(.*)|$1|;

require "getopts.pl";
Getopts('exX');

$opt_x++ if $opt_X; # -X implies -x

$TMPDIR = "/var/spool/mail/MIME";

use MIME:arser;

#------------------------------------------------------------
# dump_entity - idempotent routine for dumping an entity
#------------------------------------------------------------

sub dump_entity {
my ($entity) = @_;
my $IO;
my $not_first_part = 0;

# Print the header, converting accents if any
my $head = $entity->head->original_text;
$head =~ s/^(Subject:.*)/no_iso_markup($1)/me
if $head =~ /^Subject:.*=\?iso-8859-1\?Q\?/mi;
print $head, "\n";

# Output the body:
my @parts = $entity->parts;
if (@parts) { # multipart...
my $i;
foreach $i (0 .. $#parts) { # dump each part...
dump_entity($parts[$i]);
}
} else { # single part...
# Get MIME type, and display accordingly...
my ($type, $subtype) = split('/', $entity->head->mime_type);
#print STDERR "type - $type\n";

my $body = $entity->bodyhandle;
my $path = $body->path;
if ($type =~ /^(text|message)$/ || -T $path) { # text: display it...
if ($IO = $body->open("r")) {
print "\n" if $not_first_part++;
print to_ascii($_) while (defined($_ = $IO->getline));
$IO->close;

# If message is text/message, chances that we did the right
# thing are extremely high. So unlink the message if lying on
# the disk... -- RAM, 19/11/96

#unlink($path) or warn "$me: can't unlink $path: $!\n"
# if defined $path && -f $path;

} else { # d'oh!
die "$me: couldn't find/open '$file': $!";
}
} else { # binary: just summarize it...
my $size = ($path ? (-s $path) : '???');
print ">>> This is a non-text message, $size bytes long.\n";
print ">>> It is stored in ", ($path ? "'$path'" : 'core'),".\n\n";
}
}
print "\n";

1;
}

#------------------------------------------------------------
# smart_pack
#------------------------------------------------------------
sub smart_pack {
my ($hexa) = @_;
my $val = hex($hexa);
return "=$hexa" if $val >= 128; # We're smart right there!
return pack('C', $val);
}

#------------------------------------------------------------
# no_accent
#------------------------------------------------------------
sub no_accent {
local ($_) = @_;
tr/\xab\xbb\xe0\xe2\xe7\xe8\xe9\xea\xee\xef\xf4\xf9\xfb/""aaceeeiiouu/;
return $_;
}

#------------------------------------------------------------
# to_ascii
#------------------------------------------------------------
sub to_ascii {
my ($l) = @_;
return $l unless $opt_x; # Don't loose info unless -x or -X
$l =~ tr/\x92/'/ if $opt_x; # ';
$l = no_accent($l) if $opt_X;
return $l;
}

#------------------------------------------------------------
# to_txt -- combines =xx packing with no_accent()
#------------------------------------------------------------
sub to_txt {
my ($l) = @_;
$l =~ s/=([\da-fA-F]{2})/pack('C', hex($1))/ge;
return no_accent($l);
}

#------------------------------------------------------------
# no_iso_markup -- removes ugly ?iso-8859-1?Q escapes
#------------------------------------------------------------
sub no_iso_markup {
local ($_) = @_;
s/^(.*?)=\?iso-8859-1\?Q\?(.*)\?=/$1 . to_txt($2)/ie;
s/_/ /g;
return $_;
}

#------------------------------------------------------------
# unquote_stdin
#------------------------------------------------------------
sub unquote_stdin {
local $_;
my $encoded = 0;
my $in_header = 1;
while (<STDIN>) {
$in_header = 0 if /^\s*$/;

# All Subject: line with accents to be "un-mimed" as well.
s/^(Subject:.*)/no_iso_markup($1)/e
if $in_header && /^Subject:.*=\?iso-8859-1\?Q\?/i;

# Avoid decoding inlined uuencoded/btoa stuff... since they might
# accidentally bear valid =xx escapes... The leading \w character
# is there in case the thing is shar'ed...
# Likewise, all the lines longer than 60 chars and with no space
# in them are treated as being encoded iff they begin with M.

$encoded = 1 if /^\w?begin\s+\d+\s+\S+\s*$/ || /^\w?xbtoa Begin\s*$/;
$encoded = 0 if /^\w?end\s*$/ || /^\w?xbtoa End/;

if ($encoded || (length > 60 && !/ / && /^M/)) {
print $_;
} else {
# Can't use decode_qp from MIME::QuotedPrint because we might not
# face a real quoted-printable message...
# Inline an alternate version.

s/\s+(\r?\n)/$1/g; # Trailing white spaces
s/^=\r?\n//; # Soft line breaks
s/([^=])=\r?\n/$1/; # Soft line breaks, but not for trailing ==
s/=([\da-fA-F]{2})/smart_pack($1)/ge; # Hehe
print to_ascii($_);
}
}
return 1; # OK
}

#------------------------------------------------------------
# main
#------------------------------------------------------------

sub main {
return &unquote_stdin if $opt_e;

# Create a new MIME parser:
my $parser = new MIME:arser;

# Create and set the output directory:
$parser->output_dir($TMPDIR);

# Read the MIME message:
$entity = $parser->read(\*STDIN) or
die "$me: couldn't parse MIME stream";

# Dump it out:
dump_entity($entity);
unlink<$TMPDIR/msg-*.txt> or warn "can't unlink: $!\n";
}

exit(&main ? 0 : -1);
#------------------------------------------------------------
1;
#
# This bit below saves the message body to file, uncomment if wanted
#
#unlink</var/spool/mail/MIME/msg-*.txt> or warn "can't unlink: $!\n";