Why do I sometimes get an "Argument list too long" when I use <*>?

The <> operator performs a globbing operation (see above). By default glob forks csh to do the actual glob exansion, but csh can't handle more than 127 items and so gives the error message Argument list too long. People who installed tcsh as csh won't have this problem, but their users may be surprised by it.

To get around this, either do the glob yourself with Dirhandles and patterns, or use a module like Glob::KGlob, one that doesn't use the shell to do globbing.