Terminal 101

Command	Description
`/` (Forward Slash)	Top level directory
`.` (Single Period)	Current directory
`..` (Double Period)	Parent directory
`~` (Tilde)	Home directory
`sudo [command]`	Run command with the security privileges of the super user
`nano [file]`	Opens the Terminal editor
`open [file]`	Opens a file
`[command] -h`	Get help about a command
`man [command]`	Show the help manual of the command

Command	Description
`Ctrl + R`	Search through previously used commands
`history n`	Shows the previous commands you've typed. Add a number to limit to the last `n` items
`![value]`	Execute the last command typed that starts with a value
`!!`	Execute the last command typed

Command	Description
`cd`	Home directory
`cd [folder]`	Change directory, e.g. cd Documents
`cd ~`	Home directory
`cd/`	Root of the drive
`cd -`	Previous directory or folder you last browsed
`pwd`	Show your working directory
`cd..`	Move up to the parent directory
`cd../..`	Move up two levels

Command	Description
`ls`	Display the name of files and subdirectories in the directory
`ls -C`	Force multi-column output of the listing
`ls -a`	List all entries including those with `.`(period) and `..`(double period)
`ls -1`	Output the list of files in one entry per line format
`ls -F`	Display a `/` (slash) immediately after each path that is a directory, `*` (asterisk) after executable programs or scripts, and `@` after a symbolic link
`ls -S`	Sort files or entries by size
`ls -l`	List in a long format. Includes file mode, owner and group name, date and time file was modified, pathname, and more
`ls -lt`	List the files sorted by time modified (most recent first)
`ls -lh`	Long listing with human readable file sizes in `KB`, `MB`, or `GB`
`ls -lo`	List the file names with size, owner, and flags
`ls -la`	List detailed directory contents, including hidden files

Command	Description
`mkdir <dir>`	Create new folder named `<dir>`
`mkdir -p <dir>/<dir>`	Create nested folders
`mkdir <dir1> <dir2> <dir3>`	Create several folders at once
`mkdir "<dir>"`	Create a folder with a space in the filename
`rmdir <dir>`	Delete a folder (only works on empty folders)
`rm -R <dir>`	Delete a folder and its contents
`touch <file>`	Create a new file without any extension
`cp <file> <dir>`	Copy a file to the folder
`cp <file> <newfile>`	Copy a file to the current folder
`cp <file>~/<dir>/<newfile>`	Copy a file to the folder and rename the copied file
`cp -R <dir> <"new dir">`	Copy a folder to a new folder with spaces in the filename
`cp -i <file><dir>`	Prompts you before copying a file with a warning overwrite message
`cp <file1> <file2> <file3>/Users/<dir>`	Copy multiple files to a folder
`rm <file>`	Delete a file (This deletes the file permanently; use with caution.)
`rm -i <file>`	Delete a file only when you give confirmation
`rm -f <file>`	Force removal without confirmation
`rm <file1> <file2> <file3>`	Delete multiple files without any confirmation
`mv <file> <newfilename>`	Move/rename
`mv <file> <dir>`	Move a file to the folder, possibly by overwriting an existing file
`mv -i <file> <dir>`	Optional `-i` flag to warn you before overwriting the file
`mv *.png ~/<dir>`	Move all PNG files from current folder to a different folder

Command	Description
`cat <file>`	Output the content of `<file>`
`less <file>`	Output the contents of `<file>` using the less command that supports pagination and more
`head <file>`	Output the first 10 lines of `<file>`
`<cmd> > > <file>`	Appends the output of `<cmd>` to `<file>`
`<cmd> > <file>`	Direct the output of `<cmd>` into `<file>`

Command	Description
`ls -ld`	Display the default permission for a home directory
`ls -ld/<dir>`	Display the read, write, and access permission of a particular folder
`chmod 755 <file>`	Change the permission of a file to `755`
`chmod -R 600 <dir>`	Change the permission of a folder (and its contents) to `600`
`chown <user>:<group> <file>`	Change the ownership of a file to user and group. Add `-R` to include folder contents

Command	Description
`ps -ax`	Output currently running processes. Here, a shows processes from all users and `x` shows processes that are not connected with the Terminal
`ps -aux`	Shows all the processes with %cpu, %mem, page in, PID, and command
`top`	Display live information about currently running processes
`top -ocpu -s 5`	Display processes sorted by CPU usage, updating every 5 seconds
`top -o rsize`	Sort top by memory usage
`kill PID`	Quit process with ID `<PID>`. You'll see PID as a column in the Activity Monitor
`ps -ax`	`grep <appname>`

Command	Description
`find <dir> -name <"file">`	Find all files named `<file>` inside `<dir>`. Use wildcards (`*`) to search for parts of filenames
`grep "<text>" <file>`	Output all occurrences of `<text>` inside `<file>` (add `-i` for case insensitivity)
`grep -rl "<text>" <dir>`	Search for all files containing `<text>` inside `<dir>`

Command	Description
`Tab`	Auto-complete file and folder names
`Ctrl + A`	Go to the beginning of the line you're currently typing on
`Ctrl + E`	Go to the end of the line you're currently typing on
`Ctrl + U`	Clear the line before the cursor
`Ctrl + K`	Clear the line after the cursor
`Ctrl + W`	Delete the word before the cursor
`Ctrl + T`	Swap the last two characters before the cursor
`Esc + T`	Swap the last two words before the cursor
`Ctrl + L`	Clear the screen
`Ctrl + C`	Kill whatever you're running
`Ctrl + D`	Exit the current shell
`Option + →`	Move cursor one word forward
`Option + ←`	Move cursor one word backward
`Ctrl + F`	Move cursor one character forward
`Ctrl + B`	Move cursor one character backward
`Ctrl + Y`	Paste whatever was cut by the last command
`Ctrl + Z`	Puts whatever you're running into a suspended background process
`Ctrl + _`	Undo the last command

Command	Description
`ping <host>`	Ping host and display status
`whois <domain>`	Output whois info for a domain
`curl -O <url/to/file>`	Download file via `HTTP`, `HTTPS`, or `FTP`
`ssh <username>@<host>`	Establish SSH connection to `<host>` with user `<username>`
`scp <file><user>@<host>:/remote/path`	Copy `<file>` to a remote `<host>`

Command	Description
`du`	List usage for each subdirectory and its contents
`du -sh [folder]`	Human readable output of all files in a directory
`du -s`	Display an entry for each specified file
`du -sk*	sort -nr`
`df -h`	Calculate your system's free disk space
`df -H`	Calculate free disk space in powers of 1,000 (as opposed to 1,024)

Command	Description
`brew doctor`	Check brew for potential problems
`brew install <formula>`	Install a formula
`brew uninstall <formula>`	Uninstall a formula
`brew list`	List all the installed formulas
`brew search`	Display available formulas for brewing
`brew upgrade`	Upgrade all outdated and unpinned brews
`brew update`	Fetch latest version of homebrew and formula
`brew cleanup`	Remove older version of installed formula
`brew tap homebrew/cask`	Tap the cask repository from GitHub
`brew cask list`	List all installed casks
`brew cask install <cask>`	Install the given cask
`brew cask uninstall <cask>`	Uninstall the given cask

pixelspencil/terminal-101.md