jrep is a command-line grep-like utility written in Java.
Features:
-- Java regular expressions
(https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html)
-- Support for RE2J
(https://github.com/google/re2)
-- POSIX options (excluding -E and -G)
(http://pubs.opengroup.org/onlinepubs/009604499/utilities/grep.html)
-- most GNU grep(1) options
(https://www.gnu.org/software/grep/)
-- Extensions over GNU grep(1):
options -O, -2 and -8
Documentation:
-- https://github.com/cheusov/jrep/blob/master/scripts/jrep.pod
or
-- man page after installation