Recently I saw a stackoverflow question on why scriptinglanguages aren't suitable as Unix shell scripting languages . My answer is that shellsare strongly optimized for a different use case than programminglanguages, and this has significant effects on the design of thelanguages that they use and their semantics.Above all, shells are optimized for invoking external programs; asuccessful shell has ruthlessly pruned away everything that makesthis awkward. Scripting languages, like other languages, are insteadgenerally optimized for writing expressions, statements, and otherinternal language