You can even combine this approach with split and parallel make to do a cheap single-machine parallel sort. I use a little script that generates a Makefile that

You can even combine this approach with split and parallel make to do a cheap single-machine parallel sort. I use a little script that generates a Makefile that can be called with make -j n that splits an input file, sorts the parts, and then merges them with sort -m. It's proved to be quite handy.