Let’s say you are working on your local branch, made some changes and now not sure which files you have changed, how are you going to find your changes? You can find your changes by running the git diff command as below:
$ git diff diff --git a/LICENSE b/LICENSE index 7e4922d..442669e 100644 --- a/LICENSE +++ b/LICENSE @@ -1,4 +1,4 @@ -Copyright (c) 2014 +Copyright (c) 2015
git diff shows unstaged differences since your last commit. The last two lines show the line removed and then the new line aded in this example.
-Copyright (c) 2014 +Copyright (c) 2015
Now let’s add this file to the stage and run git diff.
$ git add LICENSE $ git diff
git diff doesn’t output anything because there are no more differences since the last file added. But if you add –staged flag to your command:
$ git diff --staged diff --git a/LICENSE b/LICENSE index 7e4922d..442669e 100644 --- a/LICENSE +++ b/LICENSE @@ -1,4 +1,4 @@ -Copyright (c) 2014 +Copyright (c) 2015
It will show show the staged differences. Run git status to show the changes need to be commited.
What if we want to unstage some files we have staged?
$ git status # On branch master # Changes to be committed: # (use "git reset HEAD
..." to unstage) # # modified: LICENSE # $ git reset HEAD LICENSE Unstaged changes after reset: M LICENSE
git reset HEAD LICENSE unstages the LICENSE file.
If we want to discard the changes we staged:
$ git checkout -- LICENSE
This will blow away all changes since last commit.
SKIP STAGING AND COMMIT
If wanted to skip staging and only want to commit, we can run following command.
git commit -a -m "Modify readme"
But there is a caveat, this will add changes from all tracked files, but doesn’t add new(untracked) files.
UNDOING A COMMIT
There maybe a time that you made a commit, and immediately realised that you didn’t want to commit some files. How do we undo it?
$ git reset --soft HEAD^ $ git status Move to commit before ‘HEAD’ # On branch master # Changes to be committed: # (use "git reset HEAD
..." to unstage) # # modified: README.txt
git reset –soft HEAD^, –soft will reset the committed files inot staging. And HEAD^ will move the commit before ‘HEAD’. Now we can make changes and commit.
If your commit went horiibly wrong, you can blow away your commit and all changes by running following command:
$ git reset --hard HEAD^
You can undo last 2 commmits and all changes:
$ git reset --hard HEAD^^
ADDING TO A COMMIT
If you forgot to add a file to a commit, we can add a file later by using –amend option.
$ git add todo.txt $ git commit --amend -m "Modify readme & add todo.txt." [master fe98ef9] Modify readme and add todo.txt. 2 files changed, 2 insertions(+), 1 deletions(-) create mode 100644 todo.txt
We can modify the commit message with the new message. This command makes whever has been staged to the last commit.
HOW DO WE SHARE OUR CHANGES?
To share our commits with others we need to use push and pull commands.
REMOTE REPOSITORY HOSTING
There are few hosted solutions out there for access control etc. Eg:-Github, Bitbucket.
To add a remote our repository we have to specify an origin.
$ git remote add origin https://github.com/Sean/git-example.git
Here origin is our name for this remote.
To get a list of all the remote repositories we have access to:
$ git remote -v origin https://github.com/Sean/git-example.git (fetch) origin https://github.com/Sean/git-example.git (push)
To push to remote:
git push -u origin master Username for 'https://github.com': Sean Password for 'https://[email protected]': Counting objects: 11, done. Delta compression using up to 4 threads. Compressing objects: 100% (6/6), done. Writing objects: 100% (11/11), 1.50 KiB, done. Total 11 (delta 0), reused 0 (delta 0) To https://github.com/Sean/git-example.git * [new branch] master -> master
If you don’t want to type password every time you push follow the link below:
PULLING FROM REMOTE
To pull changes down from the remote:
$ git pull remote: Counting objects: 5, done. remote: Compressing objects: 100% (1/1), done. remote: Total 3 (delta 1), reused 3 (delta 1) Unpacking objects: 100% (3/3), done. From https://github.com/Sean/git-example fe98ef9..4e67ded master -> origin/master Updating fe98ef9..4e67ded Fast-forward todo.txt | 1 + 1 file changed, 1 insertion(+)
HAVING MULTIPLE REMOTES
It’s common to have multiple remotes contributing to your project.
To add new remotes:
$git remote add
To remove remotes:
$git remote rm
To push to remotes:
$git push -u
Some of you might have a Heroku account up and running. It’s useful to understand how Heroku handle git.
Creating dev-server-1426... done, stack is cedar http://dev-server-1426.herokuapp.com/ | [email protected]: dev-server-1426.git Git remote heroku added
$ git remote -v heroku [email protected]: dev-server-1426.git (fetch) heroku [email protected]: dev-server-1426.git (push) origin https://github.com/Sean/git-example.git (fetch) origin https://github.com/Sean/git-example.git (push)
To push to heroku
git push heroku master