/usr/share/pcb/tools/Merge_dimPCBPS is in pcb-common 20110918-4.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 | #!/bin/sh
#
# $Id$
#
# merges PostScript files created by pcb (version >= 1.4.2) into
# a single file for backward compatibility
#
# Usage: name files...
#
# by Thomas Nau 9/96
#
if [ $# -eq 0 ]; then
	echo "Usage: `basename $0` files..." >&2
	exit 1
fi
# some system need nawk
#
case `uname` in
	SunOS)	AWK=nawk;;
	*)		AWK=awk;;
esac
$AWK '
	BEGIN								{ filecount = 0; }
	/^%!PS/								{ filecount++;  if (filecount > 1) { print "Black"; } }
	/^%!PS/,/^% PCBENDDATA/				{
		if (filecount == 1)
		{
			if (index($0, "%%Title:") == 1)
				sub(",.*$", ", merged layouts");
                        if (index($0, "Black") == 1)
                           sub ("Black", "0.9 mysetgray");
			print $0;
			next;
		}
	}
	/^% PCBSTARTDATA/,/^% PCBENDDATA/	{
		if (filecount > 1)
		{
			print $0;
			next;
		}
	}
										{ next; }
	END									{
		print "showpage";
		print "%%EOF";
	}
' $@
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