perldoc -f glob
    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 "I/O Operators" in perlop.

            Beginning with v5.6.0, this operator is implemented using the
            standard "File::Glob" extension. See File::Glob for details.