# Using digital source material

> Use the source, Luke
>
> -- a [pun][UTSL] on Obi-Wan Kenobi quote in Star Wars


## Special strings

NB! This documentation uses special strings
which you may want to adapt for your local setup:

githostref: src.ex...
gitshellhost: git.example.org


## Git

Digital source material is tracked with git.

Git is a version control system -
a repository for historic versions of file contents of a folder.



## Create


To turn a folder into a git repository,
go into the folder,
and initialize its git database:

```shell
git init
```

## Save


To "take a snapshot" of one of more files
for git archival,
first mark which files are involved
and then archive their (changes to) content:

```shell
git add foo bar
git add baz
git commit -m "Update foo bar, and add baz."
```

Alternatively you can update (but not add)
in one go:

```shell
git commit -m "Update foo bar." foo bar
```


## Share

To collaborate on a shared git repository,
first create a local copy from the shared location:

```shell
git clone git.example.org:/srv/git/src.ex.../example.git
```

Then from time to time syncronize,
first fetch eventual updates from others
and then push your local changes:

```shell
git pull
git push
```

### Publish

To publish a git repository initially created locally,
first create a new empty git publicly,
then tell your local git where its new origin will be,
and finally push your local git into its new public location:

```shell
ssh git.example.org git init --bare --shared /srv/git/src.ex.../example.git
git remote add origin git.example.org:/srv/git/src.ex.../example.git
git push --set-upstream origin main
```


## See also

* [Flight rules for Git]

[Flight rules for Git]: <https://github.com/k88hudson/git-flight-rules#readme>
  "A guide for programmers using Git about what to do when things go wrong"


## References

* [Source of this document][source]

[UTSL]: <http://catb.org/jargon/html/U/UTSL.html>

[source]: <https://source.redpill.dk/source>
  "Digital source material"