1. Open Source Software Development Environment
William Cohen
NCSU CSC 591W
January 16, 2008

2. Outline
Community
Communication
Local machine environment

3. Community Mixture of people working on OSS projects: Volunteers:
Want to learn more by doing
Think project is cool
Need project for something else
Contributors for hire:
Someone see value in the project
Adding specific features
Distributed contributors:
Different companies
Different continents
Different timezones

4. Communication
Usually on mailing lists to allow wider participation
Allows archiving information
Good for people that are differing timezones
IRC:
Interactive
Often used for quick questions
Phone:
Maybe have people awake at odd times due to TZ
Face-to-face:
Less frequent
Usually at conferences, e.g. Ottawa Linux Symposium

5. Local Machine Environment
Environment varies based on OSS project
Components:
Revision Control Systems (RCS)
Editing
Building
Debugging

6. Revision Control Systems
Manages code base for projects
Identifies each set of changes
Allow multiple versions (branches) of the software to be in development
Enables retrieval of specific versions of software
Perform comparison between different versions
Allow merging of changes from one version to another

7. RCS Vocabulary Commit Log message Update Repository Checkout
Working copy
Revision, change, changeset
Diff
Tag
Branch
Merge
Conflict
Lock

8. Example RCS Systems Centralized (one master repository): CVS
Subversion
Distributed (multiple repositories):
Mercurial
Git
Monotone

9. Editing Need write the code
Some environments such as eclipse have built in editors
Editor individual choice for many projects:
Emacs vs. vi
Pick what works for you
Some editors have highlight and other support for various languages (e.g. Vim and emacs)

10. Building
Have the required supporting software installed on the machine
Configure
Build
Install

11. Configure Determine the build environment: Operating system
Target architecture
Where supporting library and include files are located
Enable/disable optional features in software
Specify installation location

12. Build
Convert the human readable source code into computer can executable code
“make” often used to drive build:
Makefile lists dependencies for files
Makefile contains rules on how to build file from other files

13. Install Puts software in appropriate locations
Separate process after the code is built
Usually requires root permissions
May need to do other steps to:
Inform OS about new shared libraries
Enable background process

14. Debugging
Need methods of inspecting code to determine what is going wrong or point out problem area
Primitive debugging:
Use print statements to print out pieces of information
Less primitive:
Compile software with additional symbols so debugger knows where things are located
Use tools such as gdb or totalview