Perl5 リファレンス

       glob EXPR

       glob    Returns the value of EXPR with filename expansions
               such as the standard Unix shell /bin/csh would do.
               This is the internal function implementing the
               `<*.c>' operator, but you can use it directly.  If
               EXPR is omitted, `$_' is used.  The `<*.c>'
               operator is discussed in more detail in the I/O
               Operators entry in the perlop manpage.

               Beginning with v5.6.0, this operator is
               implemented using the standard `File::Glob'
               extension.  See the File::Glob manpage for