New article up on the Apple Developer Connection about scripting on the Mac. Perl gets a nice mention. (I think I saw this linked somewhere else, but I can't remember where.)
Using #!/usr/bin/env is a quick band-aid that will break in practical solutions. First, it requires an additional launch, possibly breaking setuid. Second, it depends on the callers environment, which will almost certainly be different for different invokers, leading to pulling up the wrong Perl/shell/Python/Ruby, etc.
You'd think people writing developer.apple.com[1] articles would have gotten better reviewers to point this stuff out. Oh well.
[1] He says that, also realizing that this applies to himself as well.
