The Parsing Expression Grammar Template Library (PEGTL) is a C++0x library for creating parsers according to a Parsing Expression Grammar (PEG). Grammars are embedded as regular C++ code, created with template programming (not template meta programming). These hierarchies naturally correspond to the inductive definition of PEGs. The library extends on the subject of PEGs with new expression types, actions that can be attached to grammar rules, and mechanisms to ensure helpful diagnostics in case of parsing errors. PEGs are superficially similar to Context-Free Grammars (CFGs).
csvgrep is a commandline program which enables users to execute searches on text-delimited files using a rudimentary query language. Its query language is bound to simplicity and expressivity, to be easily comprehensible. It aims at replacing both grep and awk when you are challenged to retrieve information from a text-delimited file based on the content of a specific field (or column). You can get what you want using the semantic already in the file’s underlying structure.