Thanks! Found it: http://cs61.seas.harvard.edu/wiki/2015/Shell http://cs61.seas.harvard.edu/wiki/2015/Shell This looks pretty comprehensive for an undergrad p

Thanks! Found it: http://cs61.seas.harvard.edu/wiki/2015/Shell http://cs61.seas.harvard.edu/wiki/2015/Shell This looks pretty comprehensive for an undergrad project actually... they have a grammar and everything, with pipes and redirects, which are definitely the most Unix-y concepts. And they talk about interrupts, although no user-defined signal handlers or anything. FWIW I ported the POSIX shell grammar to ANTLR, though I'm writing it in C++ (and prototyping the architecture in Python). ANTLR is actually incapable of expressing the lexer AFAICT... http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3...