# Day-12: LINUX &GIT-GITHUB CHEAT SHEET
### **File Commands**
⦁ `ls` --> Directory listing.
⦁ `ls -al` --> Formatted listing with hidden files.
⦁ `ls *.sh` --> list all the files having .sh extension.
⦁ `ls -i` --> list the files and directories with index numbers inodes.
⦁ `ls -d */` --> list only directories.(we can also specify a pattern).
⦁ `ls -lt` --> Sorting the Formatted listing by time modification.
⦁ `cd dir` --> Change directory to dir.
⦁ `cd -->` Change to the home directory.
⦁ `cd -` --> Go to the last working directory.
⦁ `cd ..` --> change directory to one step back.
⦁ `cd ../..` --> Change directory to 2 levels back.
⦁ `pwd` --> Show the current working directory.
⦁ `mkdir dir` --> Creating a directory dir.
⦁ `cat >file` -->Places the standard input into the file.
⦁ `more file` --> Output the contents of the file.
⦁ `head file` --> Output the first 10 lines of the file.
⦁ `tail file` --> Output the last 10 lines of the file.
⦁ `tail -f file` --> Output the contents of a file as it grows, starting with the last 10 lines.
⦁ `touch file` -->Create or update file.
⦁ `rm file` --> Deleting the file.
⦁ `rm -r dir` --> Deleting the directory.
⦁ `rm -f file` --> Force to remove the file.
⦁ `rm -rf dir` --> Force to remove the directory dir.
⦁ `cp file1 file2` --> Copy the contents of file1 to file2.
⦁ `cp -r dir1 dir2` --> Copy dir1 to dir2; create dir2 if not present.
### **Process management**
⦁ `ps` --> To display the current working processes.
⦁ `top` --> Display all running processes.
⦁ `kill pid` --> Kill the process with given pid.
⦁ `killall proc` --> Kill all the process named proc.
⦁ `pkill pattern` --> Will kill all processes matching the pattern.
⦁ `date` --> Show the current date and time.
⦁ `cal` --> Show this month's calendar.
⦁ `uptime` --> Show current uptime.
⦁ `w` --> Display who is online.
⦁ `whoami` --> Who you are logged in as.
⦁ `uname -a` --> Show kernel information.
⦁ `man` --> command Show the manual for command.
⦁ `df` --> Show the disk usage.
⦁ `du` --> Show directory space usage.
⦁ `free` --> Show memory and swap usage.
⦁ `whereis app` --> Show possible locations of app.
⦁ w`hich app` --> Show which applications will be run by default.
### **Searching**
⦁ `grep pattern` --> file Search for pattern in file.
⦁ `grep -r pattern dir` --> Search recursively for pattern in dir.
⦁ `command | grep pattern` --> Search pattern in the output of a command.
⦁ `locate file` --> Find all instances of file.
⦁ `find . -name filename` --> Searches in the current directory (represented by a period) and below it, for files and directories with names starting with filename.
### **File permission**
⦁ `r` --> read permission
⦁ `w` --> write permission
⦁ `x` --> execute permission
⦁ `chmod 777 filename` --> Assign read, write, and execute permission to everyone.
⦁ `chmod -R 777 dirname` --> Assign full permission to the directory and all sub- directories.
⦁ `chmod 766 filename` --> Assign full permission to the owner, and read and write permission to group and others.
⦁ `chown username filename` --> Change the ownership of a file.
⦁ `chrgp groupname filename` --> Change group ownership of a file.
### **User Management Commands**
⦁ `sudo useradd username` --> To add a new user.
⦁ `sudo passwd -l username` --> To change the password of a user.
⦁ `sudo userdel -r username` --> To remove a newly created user.
⦁ `sudo usermod -a -G groupname username` --> To add a user to a group.
⦁ `sudo userdel user groupname` --> To remove a user from a group.
### **Compression**
⦁ `tar cf` --> file.tar file Create tar named file.tar containing file.
⦁ `tar xf file.tar` --> Extract the files from file.tar.
⦁ `tar czf file.tar.gz files` --> Create a tar with Gzip compression.
⦁ `tar xzf file.tar.gz` --> Extract a tar using Gzip.
⦁ `tar cjf file.tar.bz2` --> Create tar with Bzip2 compression.
⦁ `tar xjf file.tar.bz2` --> Extract a tar using Bzip2.
⦁ `gzip file` --> Compresses file and renames it to file.gz .
⦁ `gzip -d file.gz` --> Decompresses file.gz back to file.
### **Network**
⦁ `ping host` --> Ping host and output results.
⦁ `whois domain` --> Get whois information for domains.
⦁ `dig domain` --> Get DNS information for domain.
⦁ `dig -x host` --> Reverse lookup host.
⦁ `wget file` --> Download file.
⦁ `wget -c file` --> Continue a stopped download.
### **Git-GitHub Cheat-Sheet**
**\*Git config**
Get and set configuration variables that control all facets of how Git looks and operates.
**Set the name:**
`git config --global` [`user.name`](http://user.name) `"UserName"`
**Set the email:**
`git config --global` [`user.email`](http://user.email) `"`[`yourEmail@gmail.com`](mailto:yourEmail@gmail.com)`"`
**Check the setting:**
`git config global --list`
**\*Initializing a repository**
`git init`
**\*Staging files**
`git add file1` --> Stages a single file
`git add file1 file2` --> Stages multiple files
`git add .` \--> Stages the current directory and all its content
**\*Viewing the status**
`git status`
**\*Committing the staged files**
`git commit -m “Message”`
**\*Skipping the staging area**
`git commit -am “Message”`
**\*Removing files**
`git rm file` --> Removes from working directory and staging area
`git rm --cached file` --> Removes from staging area only
**\*Renaming or moving files**
`git mv file file1.txt`
**\*Viewing the staged/unstaged changes**
`git diff` --> Shows unstaged changes
`git diff --staged` --> Shows staged changes
`git diff --cached` --> Same as the above
**\*Viewing the history**
`git log` --> Full history
`git log --oneline` --> Summary
`git log --reverse` --> Lists the commits from the oldest to the newest
**\*Unstaging files (undoing git add)**
`git restore --staged file`
**\*Comparing commits**
`git diff HEAD~2 HEAD` \--> Shows the changes between two commits
**\*Viewing a commit**
`git show 921a2ff` --> Shows the given commit
`git show HEAD` --> Shows the last commit
`git show HEAD~2` --> Two steps before the last commit
### **Branching & Merging**
**\*Managing branches**
`git branch dev` --> Creates a new branch dev
`git checkout dev` --> Switches to the dev branch
`git checkout -b dev` --> Creates and switches to dev branch
`git branch -d dev` --> deletes the dev branch
**\*Stashing**
`git stash` --> Creates a new stash
`git stash list` --> Lists all the stashes
`git stash show stash@{1}` --> Shows the given stash
`git stash apply 1` --> Applies the given stash to the working dir
`git stash drop 1` --> Deletes the given stash
`git stash clear` --> Deletes all the stashes
**\*Merging**
`git merge dev` --> Merges the dev branch into the current branch
`git merge --squash dev` --> Performs a squash merge
**\*Viewing the merged branches**
`git branch --merged` --> Shows the merged branches
`git branch --no-merged` --> Shows the unmerged branches
**\*Rebasing**
`git rebase master` --> Changes the base of the current branch
**\*Cherry picking**
`git cherry-pick fed53ed` --> Applies the given commit on the current branch
### Collaboration
**\*Cloning a repository**
`git clone url`
**\*Syncing with remote**
`git fetch origin master` --> Fetches master from origin
`git fetch origin` --> Fetches all objects from origin
`git pull` --> Fetch + merge
`git push origin master` --> Pushes master to origin
**\*Managing remote**
`git remote` --> Shows remote repos
`git remote add upstream url` --> Adds a new remote called upstream
`git remote rm upstream` \--> Removes upstream
### **Rewriting History**
**\*Undoing commits**
`git reset --soft HEAD` --> Removes the last commit, keeps changes staged
`git reset --mixed HEAD` --> Unstages the changes as well
`git reset --hard HEAD` --> Discards local changes
**\*Reverting commits**
`git revert 72856ea` --> Reverts the given commit
`git revert HEAD~3` --> Reverts the last three commits
**\*Amending the last commit**
`git commit --amend`
**\*Interactive rebasing**
`git rebase -i HEAD~5`
\>>>>>>>>>>>>>>>>> Thank you for reading! :-) <<<<<<<<<<<<<<<<