I am trying to merge two or more postscript files into one. I tried concatenation but it does not work as each postscript file may have different resource header.
Ha
As OP mentioned in the question's conclusions, concatenating the files with the line
false 0 startjob pop
in between should do the trick. So in bash, one could write something like
mkdir merge
for ps in *.ps; do
cat $ps >> merge/output.ps
echo "false 0 startjob pop" >> merge/output.ps
done
However, as the question also mentions this is only useful for printing (or PDF conversion), a viewer will probably fail to display all but the first ps file. Some more details can be found here.