I'd argue that you should probably stick to one subset of things in your bootstrap script -- and I'd say grep, awk, sed and (ba)sh go together, anything "higher level" like python/ruby/perl/tcl does not fit within that. You might want to check for python with a combination of "python -V" and the dance described above -- and, as part of bootstrapping, make a symlink (or copy, if you need to support windows and/or a filesystem without symlink support) to eg: python2. Save that tidbit as "assert-python2.sh" and then first "assert-python2.sh" then "check-bootstrap-deps.sh" and finally "bootsrap.sh" :-)