Determine if directory is under git control

Question

How can I tell if a given directory is part of a git respository?

(The following is in python, but bash or something would be fine.)

os.path.isdir('.svn') 

will tell you if the current directory is controlled by Subversion. Mercurial and Git just have a .hg/.git at the top of the repository, so for hg I can use

os.system('hg -q stat 2> /dev/null > /dev/null') == 0) 

but git status returns a nonzero (error) exit status if nothing's changed.

Is iterating up the path looking for .git myself the best I can do?

Answer 1

Just found this in git help rev-parse

git rev-parse --is-inside-work-tree 

prints true if it is in the work tree, false if it's in the '.git' tree, and fatal error if it's neither. Both 'true' and 'false' are printed on stdout with an exit status of 0, the fatal error is printed on stderr with an exit status of 128.