Top 17 Subversion SVN Interview Questions & Answers

SVN or Subversion is an open source code control system. It is used to trace all the changes made to your source code or files.  It is a repository used to manage files, folders, directories and the modification made to these files over a period of time. SVN repository provides a complete history of changes made to the files and can easily track if someone had made changes in the file.

The difference between SVN and GIT is

• Git does not support “commits” across multiple branches or tags. Subversion allows the creation of folders at any location in the repository layout
• Gits are unchangeable while subversion enables committers to treat a tag a branch and to create multiple revisions under a tag root
• Git is less preferred for handling large files or frequently changing binary files while SVN is capable of handling multiple projects stored in the same repository

In SVN repository you can store

• Source Code
• Build scripts
• Test data used by QA
• DB schema
• Project settings (When the whole team is using the same IDE)
• Project documentation (Internal and External)
• Minutes of meetings, significant e-mails, and info from the web
• Expensively generated artifacts
• And other documents related to the project

To add a file or dir in SVN the command you will use

• svn add filename
• svn add dirname

Common subversion commands include

• Import
• Checkout
• Commit
• Update

Other than these it also has commands like revert, move, copy and merge.

Update is used to update the local workspace with the changes made by the team to the repository, while commit is the process to implement changes from local to repository, in simple words, upload a file into the repository.

To apply a patch in SVN, you are required to “Create Patch” by making changes and generating the .diff file.  Then this .diff file can be implemented to the new code base using “Apply Patch”.

Command to create a new directory under version control includes

• svn mkdir directory
• svn mkdir http://url/directory

The command you will use to import your existing directory into the new repository you have to write

svn import/home/mysurface/programming file:///home/mysurface/repo/programing_repo-m “initial import”

Command svn list file:///home/mysurface/repo/programming_repo is used to see what is inside the repository.

The command used to view the difference between the local and repository version is

• svn diff filename
• svn diff dirname

The result codes G and R in svn indicates

• G code: Changes on the repo were automatically merged into the working copy
• R code: This code indicates that the item has been replaced in your working copy. This means the file was programmed or scheduled for deletion, and a new file with the same name was scheduled for addition in its place

“Revert” function will remove your local changes and reload the latest version from the repository.

To retrieve a previous version, you have to use “revert” command. But revert command will simply erase local edits, what you actually need is to “merge” command. For example, you have a file [abc.txt] and the current version is 101, and you want version 201. Then you will use the command like

• svn merge –r 101:201 abc.txt
• svn commit –m “Reverted to revision 201” abc.txt

Following commands can be used

• svnadmin dump
• svndumpfilter include
• svnadmin load
• svn remove

Best practices for SVN is

• Update and Test before commit
• Work from your own local workspace
• Commit small autonomous changes
• Validate the files you are committing, you actually changed
• Keep in touch with repository
• Watch for conflicts
• Always group your check-in logically
• Use comment

Check-Out command in SVN is used to create a local workable copy of your project retrieved from the local repository.

For example, you have a project located in the repository created at URL location http://www.guru99.com/svn/myrepo/myproject.  So you have to checkout myproject into your local system assuming myrepo is a public repository. You will use code

• svn co http://www.guru99.com/svn/myrepo/myproject .

This command will copy all your files to your current directory. If you want checkout the directory which is in a private repository, you will then use the following command

• svn co http://www.guru99.com/svn/privaterepo/myproject –username admin –password admin