$# The next command is important: it will check if your results folder doesn't contain new results compared to your archive with the current git id. If there is no errors, then you wont lose any data
$# The next command is important: it will check if your results folder doesn't contain new results compared to your archive with the current git id. If there is no errors, then you wont lose any data
$gblk pre-co
$gblk pre-co
$git co <FIRSTCOMMIT>
$git co 62efe302b6c2e7ab0dfd9c08ddfb0a87ea699c6d
$gblk co
$gblk co --mode hard # hard is used to delete file that were not present in the first commit. Otherwise only existing files at the destination commit will be updated.
$ls results
$ls results
result.txt
```
```
Not: if gblk pre-co says that you might lose data compared to the saved version of your actual commit, then use `gblk commit --update`.
### Example usage with git hooks
Git hooks are commands that can be automatically executed before and after some git commands. They are defined in the repository `.git/hooks`.
gblk can create three hooks:
*`post-commit` hook that executes `gblk commit` after every git commit
*`pre-checkout` hook that execute `gblk pre-co` before a checkout. If the command fails because some data in results folder are not saved, then the chekout is not executed.
*`post-checkout`hook that execute `gblk co` after git checkout.
