#!/bin/sh
#
# pshalf <files>
#
# Make Postscript output two pages to a page (rotated, approx 1/2 size).
#
# reads stdin or files, writes stdout.  Takes miminally conforming PostScript 
# input and produces minimally conforming PostScript output.
#
# Caveat: the output has mungled around with the showpage operator, which
# means that it cannot be used as input to any other program that must
# capture the showpage operator (for example psdraft, or pshalf itself).
#
# Written by Denise Draper	denise@cwi.nl
#

awk '
BEGIN			{ firsthalf = 1; outpages = 0;
print "%!PS-"
print "% This file has been run through pshalf; it should not be run"
print "% through any other PostScript post-processors."
PREPRO
			}
/^%%Pages:/		{ next }
/^%%PageFonts:/		{ next }
/^%%Page:/		{ if( firsthalf ) {
				if( outpages != 0 )
					print "HfDict begin ep end"
				outpages = outpages + 1
				print "%%Page: ? " outpages
				print "HfDict begin bp end"
			  } else {
				print "HfDict begin hp end"
			  }
			  firsthalf = 1 - firsthalf
			  next
			}
/^%%EndProlog/		{ 
print "% --Pshalf, by Denise Draper--"
PROLOG
print "% --End Pshalf--"
print "%%Pages: (atend)"
print "%%EndProlog"
			  next
			}
/^%%Trailer/		{ if( outpages != 0 )
				print "HfDict begin ep end"
			  print "%%Trailer"
			  print "%%Pages: " outpages
			  next
			}
			{ print $0 } ' $@