/usr/bin/head and perl lwp
I use cpan to install perl modules all the time. I recently installed Perl LWP. Unfortunately the install replaces and important text command file in /usr/bin. The file head was replaced by LWP head and this has caused some problems on my system. I found it out when I tried to install Sun’s Netbeans IDE on my mac. It wouldn’t launch. After submitting a bug request and going through the process with their tech, they discovered my head wasn’t the official one Apple ships. I did some poking around and found this on macosxhints: Perl LWP and head
I guess I have been having other problems, too. My system nighty scripts have not been running due to this issue. So if you have installed LWP, a very cool perl web library, be careful not to install the head. It asks you if you want to. Apparently I said yes during the install. If you do accidentally install it, you can copy it back from your install disk. It is in /usr/bin on the disk as it should be on your root drive.