Terminal & CLI

Commands for understanding and changing your location in the filesystem.

Term / Syntax	Name	Description	Example
pwd	Print working directory	Displays the current directory path.	pwd
ls	List directory	Lists files and directories.	ls -la
cd	Change directory	Moves the shell to another directory.	cd projects/reference-site
cd ..	Parent directory	Moves one level up the directory tree.	cd ..
~	Home directory	Shell shorthand commonly representing the current user's home directory.	cd ~

Common commands for creating, copying, moving, and removing filesystem entries.

Term / Syntax	Name	Description	Example
mkdir	Create directory	Creates a directory.	mkdir assets
touch	Create/update file	Creates an empty file or updates timestamps on many Unix-like systems.	touch README.md
cp	Copy	Copies files or directories when used with appropriate options.	cp index.html index.backup.html
mv	Move/rename	Moves or renames files and directories.	mv old-name.js app.js
rm	Remove file	Deletes files; use recursive options cautiously.	rm old-file.txt

Commands for reading files and searching text/output.

Term / Syntax	Name	Description	Example
cat	Print file	Writes file contents to standard output.	cat README.md
less	Paged viewer	Displays text one screen at a time with navigation/search.	less server.log
grep	Search text	Searches input for lines matching a pattern.	grep -n "error" server.log
find	Find files	Searches directory trees using conditions such as name or type.	find . -name "*.js"

Shell operators for composing commands and controlling standard input/output.

Term / Syntax	Name	Description	Example
|	Pipe	Sends one command's standard output to another command's standard input.	cat app.log | grep "ERROR"
>	Overwrite redirect	Writes standard output to a file, replacing its existing contents.	npm test > test-output.txt
>>	Append redirect	Appends standard output to a file.	echo "done" >> build.log
2>	Error redirect	Redirects standard error in common shells.	command 2> errors.log

Commands and syntax for environment variables and running processes.

Term / Syntax	Name	Description	Example
env	Environment	Displays environment variables in many Unix-like shells.	env
export	Set exported variable	Sets a shell variable for child processes in many shells.	export NODE_ENV=development
echo	Print value	Prints text or expanded shell values.	echo "$PATH"
Ctrl+C	Interrupt process	Common terminal shortcut for sending an interrupt signal to the foreground process.	Press Ctrl+C
npm scripts	Project commands	Runs scripts defined in a Node project's package.json.	npm run dev