B           Digest      Filter     MIME       SDBM_File  Time     util
ByteLoader  DynaLoader  GDBM_File  NDBM_File  Safe       Unicode
Cwd         Encode      I18N       ODBM_File  Socket     XS
DB_File     Errno       IO         Opcode     Storable   attrs
Data        Fcntl       IPC        POSIX      Sys        re
Devel       File        List       PerlIO     Thread     threads