slurp takes:

    * a filename,
    * a filehandle,
    * a typeglob reference,
    * an IO::File object, or
    * a scalar reference,

converts it to an input stream if necessary, and reads in the entire
stream. If slurp fails to set up or read the stream, it throws an
exception.

Homepage:
https://metacpan.org/release/Perl6-Slurp
