I find them pretty useful, the DSLs are generally just slightly modified version of BNF which is pretty straightforward to pick up. Bison + flex is my tool of c

I find them pretty useful, the DSLs are generally just slightly modified version of BNF which is pretty straightforward to pick up. Bison + flex is my tool of choice for extensive CLI interfaces in C projects. Regex is useful (hence flex) but for higher level constructs without reinventing the wheel I think it's hard to do much better than a parser generator.