James Montgomerie’s World Wide Web Log

Using the Mac or iPhone's Built In Regex Routines

In which a convenient method of using POSIX regular expressions from Objective-C is presented.

It’s a common complaint that the Mac and iPhone platforms don’t have native support for regular expressions, but that’s not entirely true. If you drop down to the UNIX core, there’s an implementation of the old (and only partially busted) POSIX regular expression interfaces. Here, I’ll show a simple Objective-C wrapper class for them that lets you use them conveniently in Mac or iPhone apps.

Before I start, some preemptive remarks: There’s a lot wrong with POSIX regexes to modern eyes. Firstly, and most glaringly, the …

PWD in the Title Bar (or, “A Regex Adventure in BASH”)


In which a five-minute hack to put the current working directory in the title bar of the Terminal descends into hours learning the surprising arcanities of BASH.

Like most developers, I spend a lot of time at my computer living in Terminal (and the rest Xcode)*. I have what might be a strange tendency to open a new Terminal window for each new task, I think so that I don’t have to lose the context in my current window. This means that after I’ve finished doing something (or in the middle, when I look at the screen and my obsessive-compulsive…