Current Perl documentation can be found at perldoc.perl.org.

Here is our local, out-dated (pre-5.6) version:

The <> operator performs a globbing operation (see above). By default glob() forks csh(1) to do the actual glob expansion, 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.