Tech Returners
Version Control
What is Version Control and why is it important?
- Version Control (aka Revision Control aka Source Control) lets you track your files over time.
- Version control is also the key to collaborative software development…
- you can work in teams on the same project easily
- manage conflicts in code on the same files
- work on different versions all at the same time
- decide what you want to keep and what you want to bin
- you can work in teams on the same project easily
- manage conflicts in code on the same files
- work on different versions all at the same time
- decide what you want to keep and what you want to bin
Why Do We Need A Version Control System (VCS)?
- Backup and Restore - Files are saved as they are edited, and you can jump to any moment in time.
- Synchronization. Lets people share files and stay up-to-date with the latest version.
- Track Changes. As files are updated, you can leave messages explaining why the change happened
(stored in the VCS, not the file). This makes it easy to see how a file is evolving over
time, and why.
- Track Ownership. A VCS tags every change with the name of the person who made it. Helpful for
blamestorming
/ giving credit.
- Branching and merging - You can branch a copy of your code into a separate area and modify it
in isolation (tracking changes separately). Later, you can merge your work back into the
common area.
GIT Vs GITHUB
| Git | Github |
|---|---|
| a tool that allows creation of a local repository | allows hosting the central repository on a remote server |
| a version control system | a repository hosting service |
GitHub terminology
- Repositories - A repository is the most basic element of GitHub. They're easiest to imagine as
a project's folder. A repository contains all of the project files (including documentation),
and stores each file's revision history.
- Branches - Branching is the way to work on different parts of a repository at one time.
- Commits - A commit, or "revision", is an individual change to a file (or set of files). It's
like when you save a file. Commits usually contain a commit message which is a brief description
of what changes were made.
- Pull Request - Pull requests are proposed changes to a repository submitted by a user and accepted
or rejected by a repository's collaborators.
- Branching and merging - You can branch a copy of your code into a separate area and modify it
in isolation (tracking changes separately). Later, you can merge your work back into the
common area.
GitHub Tour
Task 1 - setup a GitHub account
Task 2 - GitHub tutorial
Intro to the command line
- It is a tool which you can type text commands into to perform specific tasks
directly to the computer
- Through typing, many tasks can be performed more quickly, and some tasks can be automated with
special commands that loop through and perform the same action on many files — saving you
lots of time in the process.
- The computer will attempt to carry out any command that it understands. Unfortunately, the computer
does not speak in any language spoken by humans
- The people who have created the operating systems you work on have created a standard set of
commands that are built into the computer without having to be processed.
- The user interface that accepts your typed responses and displays data on the screen is called
a
shell
and there are many different varieties that you can choose from.
- Most common one is
Bash
which is the default on mac and Linux.
If you are using Windows you can download git for windows at
https://gitforwindows.org/
If you are using Windows you can download git for windows at https://gitforwindows.org/
What can we do with Command Line?
- Move around your file structure
- Create and remove folders
- Create and remove files
- Copy and paste files
- Rename files
- List files
- Run programs, servers etc
- Can also Delete!! If you instruct the computer to erase all of your data, it will cheerfully
proceed to do so.
- KEY NOTE:
Do not run a command just to see what it does.
- Make sure you understand what the command is supposed to do first, especially if the command
involves changing or removing files.
Git & The Command Line
- Git is a very powerful and popular version control system, and the only place you can run all
Git commands is from the command line.
- If you know how to run the command line version, you can probably figure out any GUI versions.
- Command-line tools are used by developers everyday, so it’s best to understand it for the future!
:)
Task 2 - create a repository for your website on GitHub
Make some changes to your website and push up to github
https://git-for-windows.github.io/
Some useful git / git bash commands
| Command | Description |
|---|---|
| git init | initialise a project for version control (do this from within the folder to be initialised) |
| git status | see where changes have been made, but not yet added |
| git add . | add all outstanding changed files into staging
You can specify a particular file if you don't want to add them all |
| git commit -m "{message}" | commit change to git and add a relevant comment to identy changes made
These will be visible against all affected files in GitHub. |
| git log | log of all commits
Note: you need to enter q (for Quit) to get out of the status window |
| git remote add origin {url} | sets up connection to between repository on your PC and the one in GitHub |
| git push origin {branchname} | sends code to the {branchname} branch on git-hub (usually master, but you have to specify) |
| git remote -v | Shows you the target url of the repository on GitHub if you are connected |
| git clone {url} | takes a copy from github and loads it on your pc
NB puts the code into a new folder |
| rm -rf .git | Trouble shooting - delete local git repository
Very useful if you have cloned to the wrong location and want to remove the error. Remember to move / copy your changed code to a tempoaray location before you remove the local repository as it will be deleted! |
| pwd | print working directory (show me the place in my folder structure that I am right now) |
| cd .. | move up one level in my folder structure |
| cd - | return to the last directory I was in (NB. This is a toggle setting) |
| ls | list structure (equivilent to dir command in DOS) |
| ls -ltr | same as ls, but shows details of file permissions, size, modification time and name, in reverse
order
For a full list of list commands, type ls --help on the command line and test a few out -l : use a long list format -t : sort by modification time, newest first -r : reverse order when sorting |
| mkdir | Make directory (folder) - will give an error if it already exists |
| rmdir | Remove (delete) a directory (NB must be empty)
A directory cannot be removed if it is still registered as a git project. use rm -rf .git to fix |
| rm | delete file(s) from a directory
rm --help gives some assistance e.g. you can delete all jpg files by typing rm *.jpg |