# Stefan Esser

#!/usr/local/bin/perl
#####################################################################
# Stefan Esser
#
# /usr/local/lib/lpdfilters/lj3-filter
#
# BSD line printer filter for HP-PCL 5 printer
# with independent init and uninit strings
# for HP-PCL and HP-GL modes
#
# Fri Jan 3 12:39:43 1992 -- Gustaf Neumann
# added support for printing of dvi-files
#
# CONFIGURATION:
# - the location of perl (headerline) /usr/local/bin/perl
# - the location of the tmp file (variable $tmpfile below)
# - the name of the dvi-filter and its options (variable $dvifilter below)

$tmpfile = "/usr/tmp/dvilj$$.dvi";
$dvifilter = "/usr/local/bin/dvilj -q -s26 -e- $tmpfile";

#--------------------------------------------------------------------
# init and uninit strings for HP-PCL and HP-GL modes
#
$text_inistr = "\033E\033&k2G"; # Text init string
$text_unistr = "\033E"; # Text un_init string

#$hpgl_inistr = "\033E\033%0B"; # HP-GL init string
$hpgl_inistr = "\033E\033&l1O\033%0B"; # HP-GL init string (rot 90 degree)
$hpgl_unistr = "\033E"; # HP-GL un_init string
$stdpwcmd = "PW 0.15;"; # default pen width in HP-GL mode

#--------------------------------------------------------------------
# describe (a superset of :-) the HP-GL commands
#
$hpglcmd = '(SM.|LB[^\003]*\003|[A-Z][A-Z][-\d,.\s]*|[.,;]|\033\..([\d;\s]*:)?|\s)';

#--------------------------------------------------------------------
# lprm sends SIGINT (is THIS signal handler necessary ???)
#
$SIG{'INT'} = 'CLEANUP';

sub CLEANUP {
print ($hpglfile ? $hpgl_unistr : $text_unistr);
unlink $tmpfile if $dvifile;
close(STDOUT);
exit 2;
}

#--------------------------------------------------------------------
# read enough (=4KByte) data to choose HP-GL or HP-PCL mode
#
$numread = read(STDIN,$buffer,4096);

#--------------------------------------------------------------------
# check whether the file is a dvi-file

$dvifile = $buffer =~ m/^\367\002/oi;
if ($dvifile) {
open(SPOOL,">$tmpfile") || die "Can't open $tmpfile for writing!";
while ($numread > 0) {
print SPOOL $buffer;
$numread=read(STDIN,$buffer,4096);
}
close(SPOOL) || exit (1);
system $dvifilter || exit (1);
unlink $tmpfile;
close(STDOUT) || exit (1);
exit (0);
}

#--------------------------------------------------------------------
# look for a sequence of HP-GL commands
#
$buffer =~ m/^$hpglcmd+/oi;

$matchlen= length($&);
$hpglfile= $matchlen > 10 && $matchlen / $numread > 0.95;

#--------------------------------------------------------------------
# add command to set pen width after 'IN', if found within the first 20 bytes
# else that default pen width
#
if ($hpglfile && substr($buffer,0,20) =~ m/IN/i) {
$pwcmd = ($buffer =~ m/(PW\s*\d+\.?\d*\s*;)/i)[0] || $stdpwcmd;
$buffer =~ s/IN\s*;/IN;$pwcmd/i;
}

#--------------------------------------------------------------------
# print init string, all data, uninit string to STDOUT
#
print ($hpglfile ? $hpgl_inistr : $text_inistr);

while ($numread > 0) {
print $buffer;
$numread=read(STDIN,$buffer,4096);
}

print ($hpglfile ? $hpgl_unistr : $text_unistr);

close(STDOUT) || exit (1);

exit (0);