temporarily ignoring files
Usually ignoring files is quite simple with Git. However, you may need to quickly hide changes in a file, perhaps for an entire development session or other reasons. Luckily there’s a simple way around this, thanks to some clever manual diving from Eelco Wiersma.
His main problem was using git commit -a, which automatically adds files that are modified into the commit object. This is a neat shortcut, but make sure you understand the staging area if you find yourself running this command all the time.
So, to temporarily ignore changes in a certain file, run:
git update-index --assume-unchanged <file>
Then when you want to track changes again:
git update-index --no-assume-unchanged <file>
Obviously there’s quite a few caveats that come into play with this. If you git add the file directly, it will be added to the index. Merging a commit with this flag on will cause the merge to fail gracefully so you can handle it manually.
Let’s go over a quick example of using the command. Changes have been made to a few files in my working directory:
$ git status # On branch master # # Changed but not updated: # (use "git add <file>..." to update what will be committed) # # modified: README.textile # modified: Rakefile # modified: TODO # no changes added to commit (use "git add" and/or "git commit -a")
If I ran git commit -a from here, all of the files would be added into the new commit. However, I want to temporarily ignore the changes in one of the files:
$ git update-index --assume-unchanged README.textile $ git status # On branch master # # Changed but not updated: # (use "git add <file>..." to update what will be committed) # # modified: Rakefile # modified: TODO # no changes added to commit (use "git add" and/or "git commit -a")
So if we commit the work now then turn the flag off, we can see that Git didn’t lose the original changes to the README. From there, you could now add them into a new commit, or revert back to the latest copy.
$ git update-index --no-assume-unchanged README.textile $ git status # On branch master # Your branch is ahead of 'origin/master' by 4 commits. # # Changed but not updated: # (use "git add <file>..." to update what will be committed) # # modified: README.textile # no changes added to commit (use "git add" and/or "git commit -a")
Check out the man page for git update-index here. If you know of other clever tricks with the index, leave a comment or submit a tip!
