#!/bin/sh

# This new_fax script is based on Martin Spott's new_fax.mime2.
# I have tightened the error checking, replaced the invocation
# of pnmscale (which used copious amounts of memory) with the
# correct stretch option for g32pbm, added support for other
# image types, and included an informative message body.
#                   Ed Doolittle <dolittle@math.toronto.edu>
#
# CVS: $Id: new_fax.mime4,v 1.1 1999/04/17 10:38:50 gert Exp $

# Martin's original comments:

# A script to send mgetty's incoming faxes via MIME encoded EMail;
# by Martin Spott (martin.spott@uni-duisburg.de), I borrowed one or two
# lines from other's ....
#
# I wrote this one because I wanted a program using as little specialized
# MIME tools as possible.
#
# This 'new_fax' only needs ' g32pbm', 'pnmscale' and 'pnmtotiff' from the
# 'pbmplus' package, 'mmencode' from the 'multimail' packages, and the rest
# is standard Unix tools.
# It was tested with thsmail under Linux and PMMail under OS/2 as frontends.

# This script is called when a message was recorded. 
# It gets the following arguments:
#      $1 : the hangup code
#      $2 : the remote id
#      $3 : the number of pages
#      $4... : the file names

# Place the correct EMail-adresses here !!!
USER="postmaster"

# Where to locate the binaries listed below
PATH=/usr/sbin:/usr/local/bin:/usr/bin:/bin:$PATH

# Select image type by uncommenting one of the following lines:
#PBMTOX=pnmtopng 	; MIME_TYPE="image/png"               ; FILE_EXTN=png
PBMTOX=ppmtogif 	; MIME_TYPE="image/gif"               ; FILE_EXTN=gif
#PBMTOX=pnmtotiff 	; MIME_TYPE="image/tiff"              ; FILE_EXTN=tif
# PBM files may be huge
#PBMTOX=cat       	; MIME_TYPE="image/x-portable-bitmap" ; FILE_EXTN=pbm
# compressed PBM files
#PBMTOX=gzip       	; MIME_TYPE="application/octet-stream"; FILE_EXTN=pbm.gz

# The binaries we need; please check carefully !!!
BASENAME=basename
CAT=cat
ECHO=echo
G3TOPBM=g32pbm
#MMENCODE=mmencode
MMENCODE=mimencode
RM=rm
SED=sed
SENDMAIL=sendmail

# How mgetty calls us.
HANGUP_CODE="$1"
SENDER_ID="$2"
NUMBER_PAGES="$3"

# Some miscellaneous data and filenames.
TMP=/tmp
MAIL_MESS=$TMP/MESS_$$
ERRO_MESS=$TMP/ERRO_$$
IMAG_FILE=$TMP/TIFF_$$
MIME_MESS=$TMP/MAIL_$$
umask 077

# Clean up from previous invocations and trap errors
$RM -f $MAIL_MESS $ERRO_MESS $IMAG_FILE $MIME_MESS
trap "$RM -f $MAIL_MESS $ERRO_MESS $IMAG_FILE $MIME_MESS; exit" 0 1 2 15

# Essential lines to put into the header of a MIME mail.
HEADERLINE_1="MIME-Version: 1.0"
HEADERLINE_2="Content-Type: multipart/mixed; boundary="attachment""

# Lines to put into the header of each MIME attachment.
ATTACHMENT_HEADERLINE_1="--attachment"
ATTACHMENT_HEADERLINE_2="Content-Type: $MIME_TYPE"
ATTACHMENT_HEADERLINE_3="Content-Transfer-Encoding: base64"

# Line to close the attachment section of a MIME mail.
ATTACHMENT_ENDLINE="--attachment--"

# Now we build our MIME mailheader using commandline arguments.
$ECHO "Subject: incoming FAX from $2 with $3 pages" >  $MAIL_MESS
$ECHO "$HEADERLINE_1"                               >> $MAIL_MESS
$ECHO "$HEADERLINE_2"                               >> $MAIL_MESS
$ECHO ""                                            >> $MAIL_MESS
$ECHO "This is a MIME encoded email."               >> $MAIL_MESS
$ECHO "$ATTACHMENT_HEADERLINE_1"                    >> $MAIL_MESS
$ECHO ""                                            >> $MAIL_MESS
$ECHO "Incoming FAX from $2 with $3 pages"          >> $MAIL_MESS
$ECHO "Hangup code was $1"                          >> $MAIL_MESS
$ECHO ""                                            >> $MAIL_MESS

# To handle each attachment we skip the first three arguments (those we
# already used for the header).
shift 3

# Handling of each fax page, whose names are given via commandline arguments.
# We have to cut off the absolute path via 'basename' and remove the dot
# which separates the page number. Also we add a filename extension and fit
# the result as filename into our attachment header - some mail frontends
# need this.
#
for i in $@
do
	# We use the second character in the filename to identify the
	# resolution of our incoming fax, so we can easily scale the fax for
	# display on a screen.
	RESOLUTION=`$BASENAME $i | $SED 's/.\(.\).*/\1/'`
	if [ "$RESOLUTION" = "n" ]
	then
		STRETCH=-s
	else
		STRETCH=
	fi
#
	# The fax is converted from G3 to PBM, it is scaled and then
	# converted to TIFF.
	# We write it into a temporary file, because my 'mmencode' doesn't
	# handle standard input correctly.
	$CAT $i                                        2>> $ERRO_MESS \
	| $G3TOPBM $STRETCH                            2>> $ERRO_MESS \
	| $PBMTOX                        >> $IMAG_FILE 2>> $ERRO_MESS
#
	# Now we put the header for each attachment into our MIME mail.
	$ECHO "$ATTACHMENT_HEADERLINE_1" >> $MIME_MESS
	$ECHO "$ATTACHMENT_HEADERLINE_2; name=\"`$BASENAME $i|cut -f1 -d\.``$BASENAME $i|cut -f2 -d \.`.$FILE_EXTN\""    >> $MIME_MESS
	$ECHO "$ATTACHMENT_HEADERLINE_3" >> $MIME_MESS
	$ECHO ""                         >> $MIME_MESS
#
	# Here we do base64 encoding of out TIFF data and add the result
	# into our MIME mail as attachment.
	$MMENCODE -b $IMAG_FILE          >> $MIME_MESS 2>> $ERRO_MESS
#
	# To clean up temporary TIFF data.
	$RM -f $IMAG_FILE
#
	# Each attachment has to end with a blank line (I believe).
	$ECHO ""                         >> $MIME_MESS
done

# To close the attachment section of our mail.
$ECHO "$ATTACHMENT_ENDLINE"              >> $MIME_MESS

# Assemble the message
if [ -s $ERRO_MESS ]; then
	$ECHO "Errors, warnings, and chatter encountered during processing:" \
                                         >> $MAIL_MESS
	$CAT $ERRO_MESS                  >> $MAIL_MESS
	$ECHO ""                         >> $MAIL_MESS
fi
$CAT $MIME_MESS                          >> $MAIL_MESS

# Sending the mail.
$SENDMAIL < $MAIL_MESS $USER

# Cleaning up mail data.
$RM -f $MAIL_MESS $ERRO_MESS $IMAG_FILE $MIME_MESS
trap "" 0 1 2 15

# Cheerio !
exit 0