From: Katy Huff Date: Sat, 4 Feb 2012 19:25:28 +0000 (-0600) Subject: Added the file for lesson 2 X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=397675597471fd06c175ef4dcb5c87a4ae169d56;p=swc-workshop.git Added the file for lesson 2 --- 397675597471fd06c175ef4dcb5c87a4ae169d56 diff --git a/Lesson-2:-Version-Control.rest b/Lesson-2:-Version-Control.rest new file mode 100644 index 0000000..4c246bc --- /dev/null +++ b/Lesson-2:-Version-Control.rest @@ -0,0 +1,320 @@ + +---------------------------------------------------------------------------------- +What is Version Control +---------------------------------------------------------------------------------- + +Very briefly, version control is a way to keep a backup of changing files, to +store a history of those changes, and most importantly to allow many people in +a collaboration to make changes to the same files concurrently. There are a lot +of verson control systems. Wikipedia provides both a nice vocabulary list and a +fairly complete table of some popular version control systems and their +equivalent commands. + +Today, we'll be using SVN. Perhaps someday we'll have a second section of this +experiment to go over distributed version control systems like mercurial. + +---------------------------------------------------------------------------------- +Checking Out The Code +---------------------------------------------------------------------------------- + +The Hacker Within has its own online code repository. You can check out code +from it at any time, from anywhere. You checked out some code this morning from +it at googlecode http://code.google.com/p/scbc-2011 in smartsvn. If you gave me +a google id, you are a fully fledged reading writing member today. Remember, +with great power comes great responsibility. + +Today, we'll check out an svn type repository at scbc-2011.googlecode.com/svn/ +. + +********************************************************************************** +Exercise : Checking out the code +********************************************************************************** + +Step 1 : Open up an internet browser and log in to google. + +Step 2 : Now go to the Checkout the source tab and click on the Password link. +Take Note. + +Step 3 : Either do this in SmartSVN or crack open a terminal. In SmartSVN, +click on the radio button that says check out project from repository. The +repository location is https://scbc-2011.googlecode.com/svn/ . + +In the terminal, if your google user name is buckybadger, do this: + +:: + + ~$ svn checkout https://scbc-2011.googlecode.com/svn/ \ + scbc-2011 --username buckybadger + +Step 4 : You should see many files download themselves onto your machine. Let's +make sure it worked. Either browse in SmartSVN or change directories to the +source code and list the contents. + +:: + + ~$ cd scbc-2011 ~/scbc-2011$ ls + + +---------------------------------------------------------------------------------- +Checking The Status of Your Local Copy +---------------------------------------------------------------------------------- + +The files you've created on your machine are your local "working" copy. The +changes your make in this local copy aren't backed up online automatically. +Until you commit them, the changes you make are local changes. When you change +anything, your set of files becomes different from the files in the official +repository copy. To find out what's different about them in the terminal, try: + +:: + + ~/scbc-2011$ svn status + + +The null result means that you're up to date with the +current version of the repository online! There are a few other responses you +might get if you or your collaborators have been active. We'll see what they +are as we go along. + +---------------------------------------------------------------------------------- +Updating +---------------------------------------------------------------------------------- + +Updating is like voting. You should update early and often , and particularly +before you make or commit any changes. This will ensure you're working with the +most up-to-date version of the repository. Updating won't overwrite any changes +you've made locally without asking, so don't get nervous. When in doubt, +update. + +:: + + ~/scbc-2011$ svn update + At revision 19. + +---------------------------------------------------------------------------------- +Adding New Files to Version Control +---------------------------------------------------------------------------------- + +This is great. You can make some changes, and commit them to version control. +But, what if you want to add something totally new? How do you make changes to +a file that doesn't exist yet? + +********************************************************************************** +Exercise : Adding files to Version Control +********************************************************************************** + +Step 1: Create a wiki page about yourself. Please tell us about yourself. Save +a file to the folder called wiki. Call it something unique, like +buckybadger.wiki. Take your time. + +:: + + ~/scbc-2011$ vi buckybadger.wiki + +Step 2: Check the status of your local copy For kicks, let's see what SVN +thinks of this. + +:: + + ~/scbc-2011$ svn status + +SVN should report that it hasn't yet been officially introduced to your file. + +:: + + ? buckybadger.wiki + +Step 3: Add the file to version control Now, introduce your file to svn by +adding it to version control. + +:: + + ~/scbc-2011$ svn add wiki/buckybadger.wiki + A wiki/buckybadger.wiki + +If you want to, commit that change. Your wiki page will be available for anyone +to see on the repo. When your done, give it a look online at +scbc-2011.googlecode.com/wiki. + +:: + + ~/scbc-2011$ svn commit -m "In commit messages, we usually explain what we've \ + done. Here, we've added a wiki page." + Adding wiki/buckybadger.wiki + Transmitting file data . + Committed revision 86. + +---------------------------------------------------------------------------------- +Removing Files from Version Control +---------------------------------------------------------------------------------- + +But, let's say you're shy and change your mind about adding this to version +control. Not all pretty faces belong on the internet, after all. If you change +your mind, and would rather not add this wiki page, try svn remove. You can +also just say rm. Be careful, this will delete your local copy of the file. + +:: + + ~/scbc-2011/wiki$ svn remove buckybadger.wiki + D buckybadger.wiki + ~/scbc-2011/wiki$ svn commit -m "a log message" + +Deleting hacker-poke/data/myPic.png Committed revision 87. + +Making and Committing a Change + +Now, recall the software-carpentry.org tutorial. You're Wolfman. The guy next +to you, he's Dracula. I'll be the Mummy. Please pick a random place in one of +the files and insert a comment, like an easter egg. + +********************************************************************************** +Exercise : Making Changes +********************************************************************************** + +Step 1 : Insert something + +If you're not in the terminal, just open up the ReadMe.wiki file. + +If you're new to the command line, you can open the best text editor like so: + +:: + + ~/scbc-2011$ cd wiki + ~/scbc-2011/wiki$ vi ReadMe.wiki + +Once it's open, you'll see some text. Just type the letter 'i' and place a line +anywhere you like. The line is a comment if it begins with a pound sign #, like +so: + +:: + + #summary A Readme for the Repository + =Read Me= + + #KATY'S COMMENT + ==Software Dependencies== + * Python 2.71 (or greater?) + * Nose + * Idle + * sqlite (3?) + * Smart SVN ? + * add more here... + + +To save it, press 'ESC', then ':wq' . + +Step 2 : Check the status of your local copy + +Now that you've changed a file, let's see what SVN thinks about your local +status. + +:: + + ~/scbc-2011$ svn status + + M ReadMe.wiki + + + +If you want, try committing your change. If it's a comment, it won't break +anything. If you think someone else has committed recently, don't forget to +update first. + +:: + + ~/scbc-2011$ svn update + + + +If SVN lets you know that someone else has committed changes to the same file +recently, hang on and watch until the next section on conflicts. If svn doesn't +complain, commit. + +Step 3 : Commit + +:: + + ~/scbc-2011$ svn commit -m "The m flag indicates that you'd like to leave a log \ + message saying what you've done. Here, we each added a comment." + +The m flag allows you to add a comment that will be stored in the repository to +help your collaborators keep track of the changes. + +---------------------------------------------------------------------------------- +Resolving Conflicts +---------------------------------------------------------------------------------- + +Some of you may have received an error message about a conflict. + +********************************************************************************** +Exercise: Resolving Conflicts +********************************************************************************** + +Step 1 : Update Before Committing + +:: + + $ svn update + + U ReadMe.wiki + + Conflict discovered in 'ReadMe.wiki'. + + Select: (p) postpone, (df) diff-full, (e) edit, (h) help for more options: + +Step 2 : Postpone + + +The options are many : + +:: + + (p) postpone - mark the conflict to be resolved later (df) diff-full - show + all changes made to merged file (e) edit - change merged file in an editor (r) + resolved - accept merged version of file (mf) mine-full - accept my version of + entire file (ignore their changes) (tf) theirs-full - accept their version of + entire file (lose my changes) (l) launch - launch external tool to resolve + conflict (h) help - show this list For now, you want to do some analysis, so + press p to postpone. + + $ p + +Step 3 : Check the Differences + +Try diff (or meld if you have it). + +:: + + $ diff myfile1.py myfile2.py Step 4 : Resolve the Conflict + +The svn command resolve in combination with --accept and one of the choices +from before will automatically delete the right files. Alternatively, you could +delete all of the files that you don't like, move the correct one to the right +filename, and try committing again. For now, we'll do it the clean way. For +example, pretend you'd like to accept yours rather than the other. + +:: + + $ svn resolve --accept ReadMe.wiki.mine Resolved conflicted state of + 'ReadMe.wiki' + +Importantly, if you decide to neglect all of your changes instead, you can +choose to revert. Try svn help revert to find out how to do that. + +:: + + $ svn revert ReadMe.wiki + + + +---------------------------------------------------------------------------------- +A test +---------------------------------------------------------------------------------- + +Okay Wolfmen, open up KatyHuff.wiki and replace my name with your own (or +someone else's, in case you're shy). + +Now, clearly we've all just tried to change the same thing at once. The first +one of us to update and commit will have no problems. However, when the rest of +us try, SVN won't let us merge our changes. We have to talk this one over and +decide who gets to commit. The rest of us will have to resolve conflicts as we +learned. Try it!