= File repository svn = The file storage revision system [http://subversion.tigris.org/ Subversion (svn)] is an integrated part of [wiki:TracGuide trac] and plays a key role in the collaboration room and project activity. First and foremost svn is the system which holds all project files. Files are available both by download from a web browser or by connecting to the file storage using a svn client. [wiki:Repository#access Read more below]. In addition to being a file storage, svn has features which are beneficial for the development of the data standards. svn contains a revision history of all changes and allows for arbitrary rollback in file versions. It has also the capability to compare and find differences between different versions of a file. == Access == #access There are several ways to access the files. The simplest ones are to use the [/browser trac svn browser] or the [/svn svn web server interface]. Browse to the file you want access to and simply open like any regular link. If you want to download many files, e.g., a complete project or the whole file storage, this is best done by using an svn client. We recommend using [http://tortoisesvn.tigris.org/ TortoiseSVN] as the svn client. To install go to http://tortoisesvn.net/downloads and download the version that fits your system. To download (parts of) the file storage you need to use the command [http://tortoisesvn.net/docs/nightly/TortoiseSVN_en/tsvn-dug-checkout.html Checkout]. Follow the link and use the following values in the Checkout dialogue: * URL of repository: `https://trac.posccaesar.org` * if you just want to download a specific folder, then input the complete path to that folder, e.g. `https://trac.posccaesar.org/projects/IDS-ADI` * Checkout directory: any folder on your client computer For the other settings the default values should be sufficient most uses. The [http://tortoisesvn.net/docs/nightly/TortoiseSVN_en/tsvn-dug-update.html Update] command downloads the changes in the repository from the version you have locally on your client computer. You should always update before you start working or reading a file to make sure that your using the latest version. To write to the file storage you will need a user account to the trac. To upload your work to the file storage, use the [http://tortoisesvn.net/docs/nightly/TortoiseSVN_en/tsvn-dug-commit.html commit] command. Since svn keeps track of all file changes there is no need to include version information in file names, e.g., like `filename_[date].txt`. If you are not uploading a changed file, but a completely new file (i.e., the file or folder does not exist in the file storage), you will need to [http://tortoisesvn.net/docs/nightly/TortoiseSVN_en/tsvn-dug-add.html add] the new files and folders first. For more information see the [http://tortoisesvn.net/docs/nightly/TortoiseSVN_en/ complete TortoiseSVN manual]. See also [wiki:RepositoryTortoiseSVN] for a walk-through of how to use the TortoiseSVN client.