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Important Git Operations

Showing Latest Commit Log

In Git, the commit you are currently on is known as the HEAD commit.

The output of the git show HEAD command will display everything the git log command displays for the HEAD commit, plus all the file changes that were committed.

$ git show HEAD commit 735359632f3ca3fe572484a4ec3e0d7b0d9c8f2d Author: codecademy <[email protected]> Date: Wed Jul 6 10:20:58 2016 -0400 scene-5.txt diff --git a/scene-5.txt b/scene-5.txt index b12dd97..5dd5d4e 100644 --- a/scene-5.txt +++ b/scene-5.txt @@ -12,3 +12,7 @@ Hamlet: I will. +Ghost: +My hour is almost come, +When I to sulphurous and tormenting flames +Must render up myself. \ No newline at end of file

Git Reset Using SHA

In Git, the git reset commit_SHA command can be used to set HEAD to the commit_SHA commit. The commit_SHA argument is the first seven digits of a previous commit’s SHA. In this example, the HEAD was reset to the commit made on Wed Jan 6.

You can use git log to see a record of previous commits and their SHA values.

$ git log commit 9d63f80111447544c303e9f1776fa08593a87310 Author: codecademy <[email protected]> Date: Wed Jan 13 18:55:53 2021 +0000 Added updates to the file commit 3ba6efbeece6ed530d85de5e313e52123fdf8cb4 Author: codecademy <[email protected]> Date: Wed Jan 6 10:11:13 2021 -0400 Completed first line of dialogue $ git reset 3ba6efb

Staging Multiple Files

In Git, the git add filename_1 filename_2 command is used to add multiple files to the staging area at once.

You can use git status to check if you properly added your files to the staging area.

$ git add scene-5.txt scene-7.txt $ git status On branch master Changes to be committed: (use ""git reset HEAD <file>..."" to unstage) modified: scene-5.txt modified: scene-7.txt

Remove File from Staging

In Git, the git reset HEAD filename command will remove filename from the staging area. Note that this command does not discard file changes from the working directory. You might use this command if you’ve added a file to the staging area, but the file includes incorrect edits.

You can use the git status command to make sure your file was properly removed from the staging area.

$ git reset HEAD scene-3.txt Unstaged changes after reset: M scene-3.txt

Rolling Back to Last Commit

In Git, the git checkout HEAD filename command rolls back all changes that have been made to filename since the last commit. In other words, this command will change your working directory to look exactly as it did when you last made a commit.

You can use the git diff command to see if the rollback was successful. If git diff doesn’t output anything, this means your working directory matches your last commit.

$ git checkout HEAD scene-5.txt $ git diff $

git stash

git stash allows you to get back to a clean commit point with a synchronized working tree, and avoid losing your local changes in the process of switching branches or tasks.

You’re “stashing” your local work temporarily in order to update a previous commit and later on retrieve your work.

You can use git stash pop to retrieve from your stash.

In this diagram, a coworker asks the programmer if they can work on something else while they have their current code open. Git stash allows their current code to be stashed as they finish the other update. Git stash pop puts the code changes back into the working directory.

git log options

git log allows you to view the commit history of the branch you currently have checked out.

git log --oneline show the list of commits in one line format. `git log -S “keyword” displays a list of commits that contain the keyword in the message.

git log --oneline --graph displays a visual representation of how the branches and commits were created in order to help you make sense of your repository history.

Git log --online --graph outputs a graphical representation of commits, showing where branches were created earlier and merged.

git commit –amend

git commit --amend flag allows you to update a commit. To avoid creating a new one, you could create your changes, stage them with git add and then type the command git commit --amend to update your previous commit.

The terminal editor will ask you to update your commit message.

Git commit amend command outputs an option to edit the last commit, including editing the commit message.

Git aliases

If you have a set of commands that you use regularly and want to save some time from typing them, you can easily set up an alias for each command using Git config.

The following terminal command

git config --global alias.glop "log --pretty=format:"%h %s" --graph"

allows you to reduce the entire command to:

git glop