SVN (Subversion) is a popular version control system used by developers to manage their source code. It allows teams to collaborate on projects, track changes, and roll back to previous versions if needed. One of the useful features of SVN is the ability to specify a specific date when checking out a project. This allows developers to go back in time and retrieve a specific version of the code, which can be useful for debugging or testing purposes. In this article, we will discuss how to update SVN checkout to a specific date, along with its externals.
First, let's understand what externals are in SVN. Externals are references to other repositories or folders that are used as a part of the main project. These references can be used to bring in libraries, dependencies, or shared code from other sources. When we update our SVN checkout to a specific date, the externals are also updated to match that date. This ensures that the code is consistent and compatible with the specific version we are checking out.
To update our SVN checkout to a specific date, we need to use the "svn checkout" command. This command is used to create a working copy of a repository on our local machine. By default, the command will retrieve the latest version of the code. However, to specify a specific date, we need to use the -r flag followed by the date in the format "YYYY-MM-DD" as shown below:
svn checkout -r {2019-01-01} https://svn.example.com/repos/project
This command will create a working copy of the code as it existed on January 1st, 2019. If we want to specify a specific time as well, we can use the format "YYYY-MM-DDTHH:MM:SS". For example:
svn checkout -r {2019-01-01T15:00:00} https://svn.example.com/repos/project
This will retrieve the code as it existed on January 1st, 2019, at 3:00 PM. It is important to note that the date and time used in the -r flag are based on the last commit made to the repository. So if we want to retrieve the code as it existed at a specific commit, we can use the commit number instead of the date.
Now, let's talk about how to update the externals along with the main project. To do this, we need to use the "svn update" command. This command is used to bring the working copy up to date with the latest changes from the repository. By default, it will only update the main project, but we can use the --set-depth flag to specify the depth of the update. For example:
svn update --set-depth infinity
This will update the main project and all its externals to the latest version. However, if we want to update the externals to a specific date, we can use the -r flag just like we did in the checkout command. For example:
svn update -r {2019-01-01} --set-depth infinity
This will update the main project and its externals to the state they were in on January 1st, 2019. We can also use the commit number instead of the date if we want to update to a specific commit.
In conclusion, updating SVN checkout to a specific date with externals is a useful feature that allows developers to retrieve a specific version of the code. This can be helpful for debugging, testing, or even for rolling back to a stable version. By using the -r flag in the checkout and update commands, we can easily specify the desired date or commit number and update our working copy accordingly. With this knowledge, developers can make use of this feature to effectively manage their codebase and ensure consistency in their projects.
