#!/bin/sh
# /usr/local/bin/lpf_vsl	by Julian Stacey
# Installed from ~jhs/public_html/src/bsd/jhs/bin/local/lpf_vsl/lpf_vsl
# See also: 			/usr/share/doc/handbook/printing.{html,latin1}
# Alternative I haven't tried: 	/usr/ports/print/apsfilter &

# Bug: date|lpr in /var/log/lpd-errs produces 2 x "[: Tue: unexpected operator"
#	I guess its the input format detector going wrong.
#	I never wrote it to work on one line files.
#	I don't much care. 

log=/var/log/lpf_vsl
dbg=echo

$dbg " " >> $log
$dbg "`date`: lpf_vsl start" >> $log

# man printcap:
#	The if filter is invoked with arguments:
#		if [-c] -wwidth -llength -iindent -n login -h host acct-file
# I just ignore arguments delivered here for now.
# JJLATER If the "-h host" component has a bjc in it, generate bjc not pcl.

# gs="-sPAPERSIZE=a4 -dFIXEDMEDIA -dNOPAUSE -q -sDEVICE=ljet3 -sOutputFile=- -"
# gs="/usr/local/bin/gs $gs -dBATCH -dSAFER"
gs="/usr/local/bin/gs -sPAPERSIZE=a4 -dFIXEDMEDIA -dNOPAUSE -q -sDEVICE=ljet3 -sOutputFile=- -dBATCH -dSAFER -"

# PDF Processing: gs now accepts PDF as input
pdfin="$gs"
$dbg "pdfin = $pdfin" >> $log
# Previously, I used to try to convert PDF to PS with this:
#	pdf2ps="/usr/local/bin/pdf2ps -sPAPERSIZE=a4"
#	Avoid pdf2ps error "exec: gs: not found" in /var/log/lpd-errs
#	PATH=:/bin:/usr/bin:/usr/local/bin ; export PATH
#	Although man pdf2ps says
#		pdf2ps [ options ] input.pdf [output.ps]
#	The second parameter is not actually optional, defaulting to pipe if
#	absent, it's just:	`basename "$1" \.pdf`.ps
#	From /usr/local/bin/pdf2ps: -c save pop -f "$1"

tmp=/var/spool/output/lpd.lpf_vsl/$$.tmp	# $$ is PID
$dbg "tmp = $tmp" >> $log
#	Keep $tmp same as in /etc/printcap
#	chmod 755 `dirname $tmp` ; chown daemon:daemon `dirname $tmp`

# Suppress Inter Field Seperator so it will not swallow the leading
# white space on the first line of plain text input, between left
# margin & first printable character.
#	IFS=

# Read first characters of first line, to determine file type.
# This syntax was not good enough:
#	read first_line
# because a PCL file contains nulls \0 (a .tiff too), EG below from
#	~/job/project/cd/label/4.6/box_vsl_i386.pcl
#	 033   E 033   &   l   2   6   A 033   &   l   0   o   0   l   0
#	   E 033   &   l   -   1   8   0   u   3   6   Z 033   *   r   0
#	   F 033   &   l   1   X 033   *   r   B 033   *   p   0   x   0
#	   Y 033   *   t   3   0   0   R 033   *   p   +   3   0   9   Y
#	 033   *   r   1   A 033   *   b   3   M 033   *   b   3   W 037
#	 333   p 033   *   b   3   W 037 333 360 033   *   b   3   W 037
#	 333 370 033   *   b   3   W 037 332 001 033   *   b   3   W 037
#	 333 374 033   *   b   3   W 037 333 334 033   *   b   3   W 037
#	 332 003 033   *   b   3   W 037 333 236 033   *   b   4   W   ?
#	 332 007 216 033   *   b   3   W 037 333 017 033   *   b   3   W
#	 037 333 007 033   *   b   5   W 037 332 017 001 200 033   *   b
#	   3   W 037 332 016 033   *   b   4   W   ? 332 036 003 033   *
#	   b   5   W 037 332 034 001 300 033   *   b   4   W   ? 332   <
#	 001 033   *   b   3   W 037 334 340 033   *   b   7   W   ? 332
#	   8  \0   & 001 300 033   *   b   5   W 037 332   x  \b 370 033
#	   *   b   9   W 037 332   p 001 360   E  \0   ? 200 033   *   b
#	   8   W 037 332 360 001   p   & 007 360 033   *   b   8   W 037
#	 332  \0 001  \0   &  \0 376 033   *   b   4   W   ? 344 037 300
#	 033   *   b   4   W   ? 344 003 370 033   *   b   4   W   ? 344
#	  \0   ~ 033   *   b   7   W   _ 332 377 377 360  \b 016 033   *
#	   b   5   W 037 331 001 013  \0 033   *   b   3   W 037 331 003
#	 033   *   b   3   W 037 331 007 033   *   b   8   W   _ 332 340
#	  \0  \0   ' 377 376 033   *   b   5   W 037 332 200  \b 001 033
#	   *   b   5   W 037 332  \0  \b 003 033   *   b   6   W   ? 344
#	 300  \0 004 007 033   *   b   3   W 037 344 200 033   *   b   3
#	   W 037 332 200 033   *   b   5   W 037 331 003 020  \0 033   *
#	   b   4   W   ? 331 001 300 033   *   b   2   M 033   *   b   2
#	   6   W 371  \0 003  \0  \0  \0 177 202 377 320 377 001 377 340
#	 307  \0 001  \0 360 373  \0 003  \0  \0 003 200 033   *   b   2
#	   8   W 371  \0 003  \0  \0  \0   @ 202  \0 320  \0 001  \0
#	 307  \0 003  \0 377 377 360 375  \0 003  \0  \0 001 300 033   *
#	   b   3   M 033   *   b   5   W 037 331 001  \n
# None of the shell variables & other unix commands (EG echo printf etc)
# tools I've tried cope with it, so to avoid writing a C program, I swallow
# the first line whole & unchanged with head.

# I lost some PCL data with this:
#	head -1 > $tmp
#	first_line=`cat $tmp`
# So now I swallow whole file (tough if its real big, this proc. wont
# work as a pipe.
cat > $tmp ; first_line=`head -1 $tmp`

# Restore Inter Field Seperator to space tab nl
# IFS="\040\011\012"

first_two_chars=`expr "$first_line" : '\(..\)'`
first_four_chars=`expr "$first_line" : '\(....\)'`
first_six_chars=`expr "$first_line" : '\(......\)'`

$dbg "`date`: Detecting format." >> $log

if [ "$first_four_chars" = "%!PS" ]; then
	$dbg "Format: POSTSCRIPT from GROFF" >> $log
	# PostScript: use Ghostscript to convert and print it
	# groff generated .ps files start: "%!PS-Adobe-3.0"
	# I do not need	to emit $first_line for gs, as I tested ghostview
	# without first line, & it displayed OK, & ghostview uses gs internaly.
	# Example:
	#	%!PS-Adobe-3.0
	#	%%Creator: Applixware
	$gs $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ "$first_four_chars" = "%!ps" ]; then
	$dbg "Format: POSTSCRIPT not from GROFF" >> $log
	$gs $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(...\)'` = '.\"' ]; then
	$dbg "Format: GROFF" >> $log
	# Note the backslash while needed in the .rof file, used to be
	# discarded by
	#	read first_line
	# before I received it here, however now using:
	#	cat > $tmp ; first_line=`head -1 $tmp`
	# it is there.
	cat $tmp | groff -U -b -s -t -Tps -dformat=ps -dumlauts=p | \
		 $gs && rm $tmp && exit 0
	# I could instead generate pcl direct from groff.
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(........\)'` = '%PDF-1.2' ]; then
	$dbg "Format: PDF-1.2" >> $log	# from ps2pdf, groff, external
	$pdfin $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(........\)'` = '%PDF-1.3' ]; then
	$dbg "Format: PDF-1.3" >> $log	# From external
	# From Phil Walters I received %PDF-1.3
%âãÏÓ
	$pdfin $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(........\)'` = '%PDF-1.4' ]; then
	$dbg "Format: PDF-1.4" >> $log	# From external
	# From Companies House change of address form
	#	%PDF-1.4?%??????
	#	2544232302EECD00
	#	5046D1E4D523F3DA
	# 0D=Carriage Return
	# From GEA Prog 2008_04.pdf
	#	%PDF-1.4?
	#	254423230
	#	5046D1E4A
	# 0A=New Line
	$pdfin $tmp && rm $tmp && exit 0
	#	GNU Ghostscript 7.07: Unrecoverable error, exit code 1
	#	Segmentation fault
	# However xpdf can display it, & can export it to a .ps file 
	# which this can print. So I discovered this works OK generating .ps
	#	 pdftops $tmp - > t.ps
	# So merge the 2:
	# /usr/X11R6/bin/pdftops $tmp - | $pdfin && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(........\)'` = '%PDF-1.5' ]; then
	# Never seen a 1.5, but presumably they exist.
	/usr/X11R6/bin/pdftops $tmp - | $pdfin && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(........\)'` = '%PDF-1.6' ]; then
	# from mk@, scanner@msd. 
	/usr/X11R6/bin/pdftops $tmp - | $pdfin && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(....\)'` = '%PDF' ]; then
	$dbg "Format: PDF Unknown Version" >> $log # Not from ps2pdf, upper case
	$pdfin $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(....\)'` = '%pdf' ]; then
	$dbg "Format: pdf unknown version" >> $log # not from ps2pdf, lower case
	$pdfin $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ $first_two_chars = '\033E' ]; then
	( echo "PCL detected by /usr/local/bin/lpf_vsl" | mail -s "PCL from lpf_vsl" jhs )
	$dbg "Format: PCL" >> $log # Escape E
	#  HP/PCL: The big HP PCL 5 book recomends all PCL files should
	#  start with this, & ghostscript generates it, so it's a safe bet.
	# Example:	"^[E^[&l26A" from gs
	# I hope data in first line is not longer than $first_line can read !
	# Some PCL files go berserk, & the whole damn file has no \n,
	# or just one at end.
	cat $tmp && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ `expr "$first_line" : '\(...\)'` = 'II*' ]; then
	$dbg "Format: TIFF" >> $log # From eg http://berklix.com/scanjet/
	/usr/local/bin/tiff2ps -a $tmp | $gs && rm $tmp && exit 0
		# The match pattern should have a null, ie 'II*\0'
		# but I haven't got the elif to match on that.
	$dbg "Format has failed" >> $log
	exit 1

elif [ "`echo \"$first_line\" | file -b -`" = "JPEG image data" ]; then
 	$dbg "Format: JPG"  >> $log
	/usr/local/bin/jpegtopnm < $tmp | /usr/local/bin/pnmtops \
		 | $gs && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

elif [ $first_six_chars = 'GIF89a' ]; then
 	$dbg "Format: GIF"  >> $log
	/usr/local/bin/gif2ps < $tmp | $gs && rm $tmp && exit 0
	$dbg "Format has failed" >> $log
	exit 1

# In a mail Removing Received: lines changes file report 
# From	"ASCII mail text"
# To:	"ASCII HTML document text" OR "ASCII text" if a non MIME
# so JJLATER trap "ASCII mail text".

else
	$dbg "Format: Dangerously Assuming ASCII" >> $log
	#  Hope its not a binary that will consume paper.
	#  Plain text: print a form at the end to eject the last page.
	# EscE: Initialise printer to default state with EscE,
	#	in case last use has left it in a mangled state
	#	EG host computer might have died in mid print.
	# EscE: Initialise again for good measure:
	#	maybe the printer might not recognise first Reset if it
	#	gets swallowed into an embedded sequence, or perhaps the
	#	printer is on a flakey dynamic multiplexer, & the first
	#	couple of characters get lost, while the multiplexer is
	#	switching the printer to a different host computer.
	#	Unlike with a hayes escape, a pcl scape does not seem to
	#	require a quiet period afterward, according to the big
	#	HP PCL manual.
	# Esc&k2G: Tell printer to treat LF as CR+LF.
	# EscE	Reset to default for next user (that on a dynamic
	#	multiplexer may not even be Unix+lpd )
	#	A printer reset also has the side effect of causing
	#	the printer to flush the last partial page (if any), whereas
	#	If we sent a FF instead, we could end up printing an
	#	extra blank page, if either { (A) the input stream of data had
	#	terminated with a page aligning FF, or (B) the last line feed
	#	happened to align the printer to end of page.
	printf "\033E\033&k2G" && cat $tmp && \
		printf "\033E" && rm $tmp && exit 0
fi

# About Trailing Form Feed:	JJLATER
# - The trailing Reset (\033E) Form Feed = New Page =Control L = (\014)
#  should be selective, sampling data at end of file, but it's not (yet),
# - Printers can be set up to also require FF or not,
#   generatin their own instead. If both do FF you get a wasted page. 
# - If neither do it, the job doesn't print till next job, or until you manually
#   send an empty page.
# - My HP is set up to generate its own trailing NP=FF
# - My Brother is set up to want an FF from computer.
# - Applixware.pcl does not have a terminating FF.
# - Groff.pcl produced by groff -U -b -s -t -Tlj4 -dformat=lj4
#	thing.rof > thing.pcl ) Have a terminating ^L^[E
# - .pcl made by groff -U -b -s -t -Tlj4 -dformat=lj4  thing.rof > thing.pcl
#    Ends with ^L^[E (& has bits of words in, not pure bitmap), for CV ~55K.
# - .pcl made by gs -sDEVICE=ljet3 -sOutputFile=thing.pcl -- thing.ps 
#    also ends in ^L^[E (but seems to have no strings, just bit map, & is
#    much larger, for my CV ~650K)

# JJLATER add a trap to rm $tmp

# Should never get this far.
echo "`date`: /usr/local/bin/lpf_vsl failure unrecognised format $tmp" | mail -s "lpf_vsl failure" root
echo "`date`: /usr/local/bin/lpf_vsl failure unrecognised format $tmp" >> $log
exit 2	# only on error.

# /usr/share/doc/handbook/handbook93.html:
# The text filter, confusingly called the input filter in LPD documentation,
# handles regular text printing. Think of it as the default filter. LPD expects
# every printer to be able to print plain text by default, and it is the text
# filter's job to make sure backspaces, tabs, or other special characters do not
# confuse the printer. If you are in an environment where you have to
# account for printer usage, the text filter must also account for pages
# printed, usually by counting the number of lines printed and comparing that
# to the number of lines per page the printer supports. The text filter is
# started with the following argument list:
#	[-c] -wwidth -llength -iindent -n login -h host acct-file