cvs, short for Concurrent Versions System, is a revision control system that is used to manage and track changes to files and directories in a software development project. It is a distributed version control system that enables multiple developers to work on the same set of files simultaneously, while keeping track of changes and maintaining a history of revisions.
The main purpose of cvs is to provide a collaborative environment for software development teams to manage source code and track changes over time. It allows developers to check out files from a central repository, make modifications to the code, and then commit those changes back to the repository. This allows for effective collaboration and ensures that changes are tracked and can be easily reverted if needed.
Some key features and concepts of cvs include:
- Version Control: cvs tracks changes to files and directories by creating a new version each time a modification is made. This allows developers to easily access previous versions of files and compare differences between versions.
- Branching and Merging: cvs supports branching, which allows developers to create independent lines of development for different features or bug fixes. Branches can be merged back together to incorporate changes from one branch into another, ensuring that all changes are properly integrated.
- Conflict Resolution: When multiple developers make changes to the same file simultaneously, conflicts may arise. cvs provides tools for resolving conflicts, allowing developers to review and merge conflicting changes manually.
- Annotated History: cvs keeps a detailed history of all changes made to files, including information about the author, date, and description of each revision. This annotated history provides a comprehensive record of the development process and can be helpful for understanding why certain changes were made.
- Access Control: cvs allows administrators to set access control rules, specifying who can read, write, or modify files in the repository. This ensures that only authorized users can make changes and helps maintain the integrity of the codebase.
- Network Transparency: cvs supports remote access to repositories, allowing developers to access and work with files from different locations. It uses various protocols, such as SSH or pserver, to facilitate secure communication between clients and servers.
cvs has been widely used in software development projects, particularly in the earlier days of version control systems. While newer and more advanced version control systems like Git and Subversion have gained popularity, cvs still remains in use in certain legacy projects. It provides a solid foundation for managing code changes and collaboration in a multi-developer environment.
cvs Command Examples
1. Create a new repository (requires the CVSROOT environment variable to be set externally):
# cvs -d /path/to/repository init
2. Add a project to the repository:
# cvs import -m "message" project_name version vendor
3. Checkout a project:
# cvs checkout project_name
4. Show changes made to files:
# cvs diff /path/to/file
5. Add a file:
# cvs add /path/to/file
6. Commit a file:
# cvs commit -m "message" /path/to/file
7. Update the working directory from the remote repository:
# cvs update