Update ident string after checkin

Question

I have enabled the expansion of $Id:$ via ident in the .gitattributes file. This allows me to quickly identify whether the file is outdated when someone else checked out my repository and installed it from there.

Now, I also sync the contents of my own Git repository to other (non-development, i.e. without Git) systems. The trouble is that the keyword expansion only happens on checkout, but my workflow is commit -> push -> sync, so the synced copies contain outdated Ids.

How can I easily force an update of the Ids after a local commit? (Bonus points for doing this automatically after any commit!)

A simple git checkout doesn't work (also not with --force), probably because the file contents haven't changed. Neither does git checkout-index --force. I only managed to accomplish this via either local modification (cumbersome, need to know the modified files):

$ echo "modified" >> file
$ git checkout file

or by temporarily checking out the previous commit:

$ git checkout HEAD^
$ git checkout HEAD@{1}

what filepattern do you apply this ident attribute to? and about how many files does that encompass? — Alexander Bird, Nov 19 '12 at 16:20
Also, a tip (though this doesn't answer your question): you can do `git checkout HEAD@{1}` and it will checkout the previous value of HEAD (http://git-scm.com/book/en/Git-Tools-Revision-Selection#RefLog-Shortnames). It keeps track of branch values at .git/logs — Alexander Bird, Nov 19 '12 at 16:25
I would recommend not using idents when checking out files. It is almost never the right solution, and causes more problems than it solves; instead, if you need to keep track of which revision corresponds to a checkout, I would use a separate file that tracks that and is not committed to git. For instance, if you have a `sync` script, have it write the current commit-id to a file, and read that file anywhere that you need to display this. — Brian Campbell, Nov 19 '12 at 16:40
Though I don't see how it's relevant, my filepattern is `*`, and I have ~ 50 Bash scripts in 2 subdirectories. The scripts are somewhat related add-ons, but can be picked individually, that's why a central version file doesn't work well here; it'd have to be a separate one for each script. — Ingo Karkat, Nov 19 '12 at 16:43

Alexander Bird · Answer 1 · 2012-11-21T19:47:20.387

1

here are some suggestions:

git checkout --force . or maybe git checkout --force file.txt

If one of those commands work, then you can create a script .git/hooks/post-commit and have that script be a one-liner which calls that command (or whatever command works) and then git will do that on every commit. I believe hook scripts automatically have the root of the working directy (where the .git folder is) set as the cwd for the script.

EDIT:

If you run touch file.txt; git checkout file.txt then git will do a full checkout including applying the ident attribute when I tested that. hopefully that can be used somehow

edited Nov 21 '12 at 19:47

answered Nov 19 '12 at 16:33

Alexander Bird

38,679
42
124
159

Unfortunately, `--force` doesn't help. But thanks for the details on the hooks; I will try that. – Ingo Karkat Nov 19 '12 at 16:48
From my understanding of your general requirements, I would try the Brian's suggestion in the comment of the question. However, I'm not sure I know what you mean by "syncing" repos. Do you mean that you do a `git pull`? or that you have some other system to copy/rsync the files to the other non-git instances? Sorry for not understanding fully; though maybe that's not even important. – Alexander Bird Nov 19 '12 at 20:12
I sync the scripts via the Unison tool (xcopy / rsync would work, too). I am aware of the limitations of ident, and that it's generally recommended against, but it seemed to fit my use case very well. – Ingo Karkat Nov 20 '12 at 09:21

score 0 · Accepted Answer · answered Sep 22 '16 at 12:55

This can be done via a post-commit hook. I've automated the setup via a script, maintained as part of my git-extensions repository:

$ git-ident-update --help
Update the expansion of $Id$ to $Id:...$ via ident in the .gitattributes
after a commit.
To do this automatically in the future, invoke with --install.
Usage: git-ident-update [--install|--uninstall|--status|--set [<path>[ <path> ...]]] [-?|-h|--help]

score 0 · Answer 3 · answered Apr 10 '20 at 23:55

0

I run touch and git checkout on recently updated files that have git Id in them using the following command:

find . -type f -mtime -1 -a -not -name '*~' | \
   xargs grep -l '$Id:' | \
   xargs --replace --verbose sh -c '{ touch {} ; git checkout {}; }'

answered Apr 10 '20 at 23:55

Nicholas Sushkin

13,050
3
30
20

Update ident string after checkin

3 Answers3