git grep(1) -h %22%40TODO%22 %7C sed -e %27s%2F%5E%5B %5D*%2F%2F%27 %7C sort %7C uniq --count %7C sort --reverse --sort%3Dnumeric
Print lines matching a pattern
-h, -H
    By default, the command shows the filename for each match.  -h option is used to suppress this
    output.  -H is there for completeness and does not do anything except it overrides -h given earlier
    on the command line.
-e
    The next parameter is the pattern. This option has to be used for patterns starting with - and should
    be used in scripts passing user input to grep. Multiple patterns are combined by or.
-c, --count
    Instead of showing every matched line, show the number of lines that match.
source manpages: git-grep