Searching for commits which reference a given object

Question

I've got a file that's been installed on my system that is known to be part of a git repo. I'd like to find out which commit(s) (re-)introduced that version of that file, ie which commit is responsible for putting the file in its current state.

I know that the file is in the repo because git show $(git hash-object $the_file) works.

At this point I don't really need a solution to this example problem, I'm more just hoping to learn a bit more about how to navigate git's data structures.

Answer 1

How about git log <the file>?

Answer 2

If the current version introduce a particular comportement you can test (by a unit test program, a shell script, etc.), you can use the git bisect tool to find the commit responsible for this comportement.

Here is the manual of this command: http://www.kernel.org/pub/software/scm/git/docs/git-bisect.html

Answer 3

Get the hash of given version of file using git hash-object <file>, then use git log --raw -- <file>, and search through pager (it is '/' in 'less' and in 'more') for this hash.

Answer 4

Thanks to @Jefromi for pointing out the duplicate. Since this question hasn't been closed as a duplicate, I'm going to answer it with a reference to the accepted answer on that other thread, which contains a perl script that seems to do just what I want, with more or less optimal efficiency.