Lately, I’ve been trying to dig into shell scripting. While reading through a Bash Scripting Guide and testing out the expr command line utility I found that the OS X version of expr is very limited compared to the linux/standard version. All of the nice string related commands outlined on the Man Page for expr don’t work on the OS X version of the utility. This is severly limiting especially because (as far as I know) there is no way to find the index of a substring in Bash scripting except through expr. In any case, I’ve filed a bug-report (rdar://4269034) about this problem.
On a side-note, thank-you everyone who responded to my previous post on ‘What is Missing?’. I will be making one of the suggested projects.