Command reference

What a command does, what it is made of and where it can bite. With examples from the tracks and one-click practice.

Bash

pwd — Show which folder you are in
ls — List files and folders
cd — Go to another folder
mkdir — Create a folder
touch — Create an empty file or update its modification date
cp — Copy a file or a folder
mv — Move or rename a file
rm — Delete files and folders
cat — Print a file to the terminal
head — Show the first lines of a file
tail — Show the last lines of a file, or follow it
less — Read a big file page by page
wc — Count lines, words and bytes
grep — Find the lines with some text in files
find — Find files and folders by name, type and more
which — Find out where a program lives
> >> 2> — Output redirection. Write a command's output to a file instead of the screen
| — The pipe. Pass the output of one command to the input of another
sort — Sort lines and drop duplicates
echo — Print text or the value of a variable
export — Set an environment variable for the programs you run
env — List environment variables
source — Run the commands from a file in the current shell

git config — Set up git: the author name and email, the editor and other settings
git init — Create a new repository in the current folder
git clone — Download a repository from a server with its whole history
git status — See what changed in the folder and what is already staged
git add — Stage changes so they go into the next commit
git commit — Save the staged changes to history as a new commit
git diff — See exactly what changed in your files, line by line
git branch — List, create, rename or delete branches
git switch — Switch to another branch, or create a new one and switch to it
git merge — Bring the changes from another branch into the current one
git log — Show the commit history
git show — Show one commit: its message, author and every change in it
git blame — Find out who last changed each line of a file, and in which commit
git restore — Discard edits in a file or unstage it
git reset — Move the branch to another commit, for example to undo the last commits
git revert — Undo a commit with a new commit, without rewriting history
git remote — List and add remote repositories
git fetch — Download new commits from the server without touching your branches
git pull — Download changes from the server and merge them into the current branch
git push — Send your commits to the server
git stash — Put uncommitted edits aside for a while and bring them back later
git rebase — Move a branch's commits onto a new base, or rewrite the last commits