grep с регулярными выражениями, совместимыми с Perl (a grep with Perl-compatible regular expressions.)
BINARY FILES
By default, a file that contains a binary zero byte within the
first 1024 bytes is identified as a binary file, and is processed
specially. (GNU grep also identifies binary files in this
manner.) See the --binary-files option for a means of changing
the way binary files are handled.
