'git-grep' [--cached]
[-a | --text] [-I] [-i | --ignore-case] [-w | --word-regexp]
[-v | --invert-match]
- [-E | --extended-regexp] [-G | --basic-regexp]
+ [-E | --extended-regexp] [-G | --basic-regexp] [-F | --fixed-strings]
[-n] [-l | --files-with-matches] [-L | --files-without-match]
[-c | --count]
[-A <post-context>] [-B <pre-context>] [-C <context>]