Linux Commands

Command	Description
pwd	Path of folder I'm in
cd	Change directory
ls	Show content of directory
cat	List file content
less	List file content. Scrolling possible
touch <file>	Create a file
ln -s <target> <link>	Create a symlink to a file
ln -sfn <path to new target> java	Change target of existing symlink
cp <destination>	Copy files
mv <destination>	Move or rename files
mkdir	Create a new directory
rm	Remove files or directories
locate (-i =ignore-case)	Locate a file by name
find <directory> -name <name>	Finds a file by name
grep	Search for text in a given file
df	Show disk space usage
du -h fileName	Show file size
head -n 10 fileName	Show first n lines of a file
tail -n fileName	Show last n lines of a file
diff file1 file2	Show diff of two files
chmod	Change file permissions
chown	Change owner of a file
top	Show running processes
ctrl + r	Reverse search for executed commands
wget <url>	Download files
alias anExample='date +%H:%M:%S'	Create an alias. (Will be removed if shell is closed!)
unalias anExample	Remove alias
let	Evaluate arithmetic expressions
>	Overwrite file content
>>	Append file content
find /var -name syslog 2> /dev/null 1> syslog	Errors (2) will be removed. Only normal output (1) will be written to file
cmd1|cmd2	Data from cm1 will be transferred to cmd2
date --iso-8601=ns	Get date in ISO-8601

Show content of directory (ls)

Command	Description
ls -a	Show hidden files
ls -al	Also shows details like permissions

Concatenate (cat)

Command	Description
cat > myFile	Creates a new file
cat file1 file2 > file3	Creates a new file with content of file1 and file2

Remove (rm)

Command	Description
rm -r	Remove directory and content
rm -i *	Prompt before file removal

File permissions (chmod)

chmod u=rwx,g=rx,o=r fileName

• user can read, write and execute the file
• group members can read and execute the file
• others can read the file

Alternative chmod 754 fileName

• 4 = read
• 2 = write
• 1 = execute
• 0 = no permission
• 7 = 4+2+1 (read, write, execute)
• 5 = 4+1 (read, execute)

GIT Commands

Command	Description
git init	Create an empty Git repository or reinitialize an existing one
git remote add origin [email protected]:dan-za/myRepo.git	Add remote repository
git config --get remote.origin.url OR git remote get-url origin	Show remote repository URL
git status	State of git working directory
git fetch	Checks if changes are available
git pull	Pulls changes
git add -u .	Add deleted and unmodified files only
git add (-A)	Add (all) file(s)
git commit -m 'comment'	Commit changes to local repo
git push origin master	Push changes in local repo to remote repo
git checkout -b branchName	Create and switch to branch
git checkout master	Switch branch
git merge branchName	Merge branch into current branch
git branch -d branchName	Delete local branch
git push origin --delete branchName	Delete remote branch
git log	Show commit history