Day13 of #90DaysofDevOps: Linux & Git-GitHub Cheat Sheet

pwd
Print Working Directory
Displays the current directory path.
ls [options]
List Directory Contents
Lists files and directories in the current location. Options:
- -a → Show hidden files.
- -l → List in long format with detailed info.
cd [directory]
Change Directory
Navigates to the specified directory.
- cd .. → Move up one directory level.
mkdir [directory_name]
Make Directory
Creates a new directory.
rmdir [directory_name]
Remove Directory
Deletes an empty directory.
rm [file]
Remove File
Deletes a file or directory.
- -r → Remove directories and contents recursively.

touch [filename]
Create a File
Creates an empty file.
cat [file]
Concatenate Files and Output Content
Displays content of a file or concatenates multiple files.
cp [source] [destination]
Copy Files
Copies a file or directory from source to destination.
mv [source] [destination]
Move or Rename Files
Moves or renames a file/directory.
nano [file]
Edit Files
Opens the file in a simple text editor (Nano).
vim [filename]
Open File in Vim Editor
Opens the specified file in the Vim text editor. If the file doesn't exist, Vim will create a new file with the given name.

find [directory] -name [filename]
Find Files by Name
Searches for files matching the name in the specified directory.
grep [pattern] [file]
Global Regular Expression Print
Searches for a specific pattern within a file.

chmod [permissions] [file]
Change File Permissions
Changes the permissions of a file (e.g., chmod 755 script.sh).
chown [owner]:[group] [file]
Change File Owner/Group
Changes the owner and group of a file.
usermod -aG [groupname] [username]

command can be used to add a user to one or more groups.
- -a: Append the user to the specified group(s). This option is critical when adding the user to additional groups without removing them from their existing groups.
- -G: Specifies the group(s) the user will be added to. Multiple groups can be specified by separating them with commas.

apt update
Update Package List
Updates the package list on Debian-based systems.
apt upgrade
Upgrade Installed Packages
Installs the latest versions of all packages.

git config --global user.name "Your Name"
Set Username
Configures the Git username for commits.
git config --global user.email "mail@example.com"
Set Email
Configures the Git email address for commits.
git init
Initialize Git Repository
Creates a new Git repository in the current directory.

git clone [repository_url]
Clone a Repository
Downloads an existing repository from a URL.
git status
Check Status
Displays the state of the working directory (untracked, modified, staged files).
git add [file]
Stage Changes
Adds changes in the file(s) to the staging area for the next commit.
git commit -m "Commit message"
Commit Changes
Commits the staged changes with a message.
git push [remote] [branch]
Push Changes to Remote
Sends commits from your local repository to the remote repository.
git pull [remote] [branch]
Pull Changes from Remote
Fetches and merges changes from the remote repository.

git branch
List Branches
Lists all branches in the repository.
git branch [branch_name]
Create New Branch
Creates a new branch.
git checkout [branch_name]
Switch Branches
Create a New Branch and Switching to It.
git merge [branch_name]
Merge Branch
Merges changes from the specified branch into the current branch.
git rebase [branch_name]
Rebase Branch
Reapplies commits on top of another base tip.

git reset [file]
Unstage a File
Removes the file from the staging area without deleting changes.
git reset --hard [commit]
Reset to a Specific Commit
Resets your working directory and index to a specific commit, deleting all newer commits.
git revert [commit]
Revert Commit
Creates a new commit that undoes changes made by a previous commit.

git remote add origin [repository_url]
Link Repository to GitHub
Links the local repository to the remote GitHub repository.
git push origin [branch_name]
Push to GitHub
Pushes the changes to the specified branch on GitHub.
git fetch
Fetch Changes
Retrieves new changes from the remote without merging them.

Stay tuned for more insights as I continue my #90DayOfDevOps challenges. If you have any questions or tips, feel free to share them in the comments.

Let’s keep learning and growing together! 🚀