git-grep(1) - Print lines matching a pattern
    Instead of searching tracked files in the working tree, search blobs registered in the index file.
    Search files in the current directory that is not managed by git.
    In addition to searching in the tracked files in the working tree, search also in untracked files.
    Also search in ignored files by not honoring the .gitignore mechanism. Only useful with --untracked.
    Do not pay attention to ignored files specified via the .gitignore mechanism. Only useful when
    searching files in the current directory with --no-index.
-a, --text
    Process binary files as if they were text.
-i, --ignore-case
    Ignore case differences between the patterns and the files.
    Don’t match the pattern in binary files.
--max-depth <depth>
    For each <pathspec> given on command line, descend at most <depth> levels of directories. A negative
    value means no limit. This option is ignored if <pathspec> contains active wildcards. In other words
    if "a*" matches a directory named "a*", "*" is matched literally so --max-depth is still effective.
-w, --word-regexp
    Match the pattern only at word boundary (either begin at the beginning of a line, or preceded by a
    non-word character; end at the end of a line or followed by a non-word character).
-v, --invert-match
    Select non-matching lines.
-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.
    When run from a subdirectory, the command usually outputs paths relative to the current directory.
    This option forces paths to be output relative to the project top directory.
-E, --extended-regexp, -G, --basic-regexp
    Use POSIX extended/basic regexp for patterns. Default is to use basic regexp.
-P, --perl-regexp
    Use Perl-compatible regexp for patterns. Requires libpcre to be compiled in.
-F, --fixed-strings
    Use fixed strings for patterns (don’t interpret pattern as a regex).
-n, --line-number
    Prefix the line number to matching lines.
-l, --files-with-matches, --name-only, -L, --files-without-match
    Instead of showing every matched line, show only the names of files that contain (or do not contain)
    matches. For better compatibility with git diff, --name-only is a synonym for --files-with-matches.
-O [<pager>], --open-files-in-pager [<pager>]
    Open the matching files in the pager (not the output of grep). If the pager happens to be "less" or
    "vi", and the user specified only one pattern, the first file is positioned at the first match
-z, --null
    Output \0 instead of the character that normally follows a file name.
-c, --count
    Instead of showing every matched line, show the number of lines that match.
    Turn off match highlighting, even when the configuration file gives the default to color output. Same
    as --color=never.
    Print an empty line between matches from different files.
    Show the filename above the matches in that file instead of at the start of each shown line.
-p, --show-function
    Show the preceding line that contains the function name of the match, unless the matching line is a
    function name itself. The name is determined in the same way as git diff works out patch hunk headers
    (see Defining a custom hunk-header in gitattributes(5)).
-A <num>, --after-context <num>
    Show <num> trailing lines, and place a line containing -- between contiguous groups of matches.
-B <num>, --before-context <num>
    Show <num> leading lines, and place a line containing -- between contiguous groups of matches.
-W, --function-context
    Show the surrounding text from the previous line containing a function name up to the one before the
    next function name, effectively showing the whole function in which the match was found.
-f <file>
    Read patterns from <file>, one per line.
    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.
--and, --or, --not, ( ... )
    Specify how multiple patterns are combined using Boolean expressions.  --or is the default operator.
    --and has higher precedence than --or.  -e has to be used for all patterns.
    When giving multiple pattern expressions combined with --or, this flag is specified to limit the
    match to files that have lines to match all of them.
-q, --quiet
    Do not output matched lines; instead, exit with status 0 when there is a match and with non-zero
    status when there isn’t.

    Instead of searching tracked files in the working tree, search blobs in the given trees.