I recently wrote about Casual RE Builder, one of Charles Choi’s Casual Suite apps. As I wrote then, it goes a long ways towards making RE-builder usable for those of us who can’t remember all the commands necessary to export the resulting regex to a useful place.
While he was working on Casual RE-builder, Choi discovered that sometimes—usually in the Dired subsystem—Emacs expects “grep-like” regular expressions rather than the Emacs style. This is undoubtedly because Emacs outsources certain tasks to external grep routines. The fact that the particular regexp subset used depends on what flavor of grep you have installed makes things even more complicated. If you’re like me, all of this is news to you. Somehow, I’ve managed to stumble through using Dired without realizing that it was pulling a bait-and-switch on me.
Regardless, Choi has come to the rescue. He’s changed Casual RE-builder to add an option to export the regexps from RE-builder in grep format. It’s a small thing but it makes Casual RE-builder even more useful.
I’ve already installed Casual RE-builder and presumably I’ll get Choi’s latest changes with my next update. This is, I say again, a really useful package and if you use regexps at all in Emacs, you should take a look at it.