How to check if your local git repository is up to date

Question

Basically am writing a crontab task that checks my remote git repository every 1 minute. If there is changes, it pulls them (to the local repo), go through each commit and does runs a grunt selenium task on each commit.

The part that am sort of stuck is how to find out if the remote git repository has new content and i need to pull!

Answer 1

You can use git ls-remote to find that out:

git ls-remote origin master

This command will get the latest sha-1 id of the master branch, you can specify as many branches as you want, or none to get them all. You can use that to compare with the local branch.

However, it might be more efficient to fetch all the changes so you don't have to do the same network operation twice:

git fetch origin

This way you will get the updates in 'origin/master', and you can compare with 'master' to see if there are updates. This doesn't merge or rebase, so once you have detected there are updates, you can do git pull or git merge or git rebase, whatever it is that you want to do.

Answer 2

git fetch
git log ..origin/master --oneline | wc -l

It outputs the number of revisions (commits) that would be applied when pulling.

If it's greater than 0 it means that there is new content.