Week 13 Flashcards
What does a version control system do?
Tracks changes to source code
Helps integrate your changes with changes from someone else
Lets you manage parallel streams of development on the code
What are the two types of version control system approaches?
Centralized vs distributed control
What are the differences between centralized and distributed version control systems?
Both have the concept of a master repository
Centralized control runs all the major commands and log information through the master repository.
Distributed places a more extensive copy of the history in the local working copy.
Which of the two types of version control systems are better for online and offlie operations
Centralized is better if you have access to online
Distributed makes working offline easier, but merging revisions can require more complex algorithms
Which of the two types of version control systems are more convenient for users?
The distributed is more easy for users, but te centralized is easier to manage and build.
Describe the lock-modify-unlock system
You can exclude other uses from accessing a file by locking it. It also serializes all changes to the files. There are no conflicts because only one person can access at a time.
Describe the copy-modify-merge mode of operation?
You can get your own editable copy of the file and change as you like.
Merge your changes with everyone elses when you’re ready
What is a trunk?
The one main stream of development
What is a branch?
Side-development projects
What is a tag?
STable checkpoints that you might want to call back
What is a merge?
Sometimes the branch recombines with the trunk.
What belongs in a version control system?
Anything that is an original document.
source code
Documentation
supporting images
What doesn’t belong in a version control system?
Anything that is derived.
Object files
pdf files
executable files
What does svn stand for?
Subversion
What behaviour mode does subversion have?
copy-modify-merge
What are the two types of branch merging?
Bring updates from the trunk into a branch
Migrate a branch to the trunk and close the branch
What are the steps to bring updates from the trunk into a branch?
- Called a sync merge
- Commit all the branch changes to the branch repository
- Use the ‘svn merge’ command to bring over the content from the trunk
- Commit the update to the branch
What are the steps to migrate a branch to the trunk close the branch?
- Called a reintegrate merge
- commit all the branch changes to the branch repository
- get a copy of the trunk
- Use the svn merge –reintegrate command to move all the branch content to the trunk and close off the branch
- resolve any conflicts to commit the merge to the trunk
What do changelists do?
Let you make lists of files that are being modified for a common reason
What the purpose of a changelist
Lets you ask for status and commit on just those files
How do we create a changelist?
svn changelist listname file1 file2
What are the commands for file locking?
svn lock
svn unlock
can steal a lock from someone else with the –force flag
How do we get more information on a svn file?
svn info
Ignoring files?
svn propset svn:ignore pattern_to_ignore target_repository
What do shells like bash allow you to do?
Write programs in them too
What is a shell program called?
A script
When are scripts typically used?
Created to automate some process that involves invoking a sequence of programs
A script is as simple as what?
A text file with commands to execute. Usually one command per line.
what are the three ways we execute a script?
1) Read in the text to your current shell
2) Invoke the shell (a new instance) and pass the script as a parameter)
3) Make the script act like a program of its own
How are command line arguments accessed?
With the variable names $1, $2
What are the semantic elements for any language?
Variables
expressions
conditionals/selection
Loops
What is a subshell?
Within a script, you can execute another program or script in its own shell using the back quotes
