https://github.com/maltzj/google-style-precommit-hook/blob/95c2f5632710e095220e22cc1a4e1a1451abf75f/format-code.sh#L11 $(command) is a bash or other new shell issue. On many systems sh is a posix limited shell. This issue is fixed in https://github.com/maltzj/google-style-precommit-hook/pull/17