Version Control Software and Source Code Repositories Levi D. Smith Knoxville Game Design January 2018

Overview • I don’t claim to be an expert, but know enough to do the basics • Software Configuration Management (SCM) • Version Control Systems • The tool used for managing source code • Distributed vs Centralized (client / server) • https://en.wikipedia.org/wiki/Comparison_of_version_control_software • Source Code Repositories • Where your code is hosted • Public and private • Paid and free • Can also host server yourself, remote file share, or just local system

Benefits • See diffs between revisions (deltas) • Roll back to a stable version • Timestamps of when commits were made • Accessibility to multiple developers • Better than sharing a Dropbox or Google drive folder • More elegant than backing up directories • Analysis tools and web view of source code

Disadvantages • All developers must have the tool and access to the repository • Developers resistant to using version control • Time investment for managing repository

General Workflow Create repository on server Clone repository to local workstation Edit code Commit changes Push changes to repository on server

Version Control Software

Older Version Control Systems • Source Code Control System (SCCS), 1972 • Concurrent Versions System (CVS), 1990 • Check-in and Check-out code • Can lock code that is checked out

Microsoft Version Control Systems • Visual Source Safe, 1994 • Required client licenses • Team Foundation Server (TFS) • Integrates well with Visual Studio

Subversion (SVN) • Created by CollabNet in 2000 • Now a part of the Apache Foundation project • https://subversion.apache.org/ • Command line interface • Tortoise is a graphical interface that integrates into operating system • Shows icons for new and updated files • Icons may be out of sync • Also has repo browser • Commit identifiers are sequential numbers • AnkhSVN • Support for Subversion in Visual Studio

Mecurial • Supported by Atlassian Source Tree graphical interface • BitBucket default • Command line interface and Tortoise support

Git • Originally developed by Linus Torvalds in 2005 • https://git-scm.com/ • Command line interface • Open Source graphical tool • Also supported by Atlassian Source Tree • Changes have to be “staged” before commit • Commit identifiers are cryptic strings • Can push local repository to server • Differences with SVN • https://help.github.com/articles/what-are-the-differences-between-subversion-and- git/

Ignore Files • Useful for excluding files to be committed • In Unity, don’t need to check in /Library, /Temp, and your builds • .gitignore (Git), .ignore.txt (Mecurial) • Can set global ignore file, so that same folders are ignored for every project • Can use regular expressions

Other topics • Merging • Always commit after a merge • Forking • Typically don’t do it • Rebase, Archive, Branch • Blame

Source Code Repositories

SourceForge • Older host popular for Open Source projects • Supports Subversion

BitBucket • Can host free private repositories • Supports Mecurial and Git • Repository size capped to 2GB

GitHub • Public repositories are free • Private repositories are $7 per month • Graphical charts showing checkins • Wiki, Issue (bug) tracking • Git ≠ GitHub