It would not be terribly difficult to create a workalike on other * nixes as the task is effectively just mapping your filesystem's stat(2) metadata onto an SQL

It would not be terribly difficult to create a workalike on other * nixes as the task is effectively just mapping your filesystem's stat(2) metadata onto an SQLite db, with a virtual table representing file content and a user defined function that calls exec()* . SQLite gives you most of what you need here for free and makes the rest relatively easy. In fact a module containing the implementations for the latter can even be loaded directly into the existing sqlite3 cli. If you added an inotify daemon and FTS indexes you would have essentially a clone of Spotlight and other indexed filesystem search engines. * piping the filenames somewhat obviates this though