rgrep.1 -iC 2 'ERROR' /var/log/mxh.lol
print lines matching a pattern
-i, --ignore-case
       Ignore case distinctions in both the PATTERN and the input files.  (-i is specified by POSIX.)
    -C NUM, -NUM, --context=NUM
           Print NUM lines of output context.  Places a  line  containing  a  group  separator  (--)  between
           contiguous  groups  of  matches.   With the -o or --only-matching option, this has no effect and a
           warning is given.

File and Directory Selection
    -a, --text
           Process a binary file as if it were text; this is equivalent to the --binary-files=text option.
source manpages: rgrep