Xcl---A family of programming lanquage-based shells
M.A. Roschke · University of North Texas Digital Library (University of North Texas) · 1989
As the three major UNIX shells have emerged, they have shown little inclination to include syntax and semantics from existing programming languages. The first of these shells, sh, contains only a small amount of C-like syntax. Csh provides some C language expression syntax, but includes very little other C syntax. The newest of these shells, ksh, also includes some C-like expression syntax, although they contain some significantly un-C-like syntax in such areas as relational and logical operators. Several much less widely used shells have been written that much more closely resemble particular programming languages. However, each of these shells have the disadvantage of not being based upon a widely used programming language. In addition, interactive commands tend to be difficult to enter because they must frequently be entered using normal programming language constructs such as function calls. Thus, the vast majority of programmers of today's UNIX shells must deal with a shell interface that is not based upon any familiar programming language. This paper describes some of the features of the xcl family of shells. Each of these shells is based closely upon an existing programming language and provides the user with a familiar and highly programmable shell interface. 7 refs.