Quick-reference cards for Git, AWS, and the Linux & macOS terminal — the commands you reach for every day.
Branching, merging, rebasing, stashing, remotes, log inspection, and history rewriting.
git --helpS3, EC2, IAM, Lambda, CloudWatch, and SSM — the most-used commands with flags explained.
aws helpman <command>
Open the manual page for any command
<command> --help
Print a short usage summary
which <command>
Show the full path of an executable
history | grep <term>
Search your shell history
Ctrl+R
Reverse-search shell history interactively
Ctrl+L
Clear the terminal screen
ls -lah
List files with sizes, hidden files, human-readable
find . -name "*.log"
Recursively find files matching a pattern
grep -rn "text" ./dir
Recursive grep with line numbers
du -sh *
Show disk usage of each item in the current directory
df -h
Show free disk space on all mounted volumes
cp -r src/ dst/
Copy directory recursively
mv old new
Move or rename a file/directory
rm -rf dir/
Force-remove a directory and all contents (no undo)
tar -czf out.tar.gz dir/
Create a gzip-compressed archive
tar -xzf file.tar.gz
Extract a gzip archive
ps aux | grep <name>
Find a running process by name
kill -9 <PID>
Force-kill a process by PID
lsof -i :<port>
Show what is listening on a port
curl -I <url>
Fetch HTTP response headers only
curl -o file <url>
Download a URL to a file
ssh -i key.pem user@host
SSH with a private key file
scp file user@host:~/
Secure-copy a file to a remote host
cmd | less
Page through long output
cmd > file.txt
Redirect stdout to a file (overwrites)
cmd >> file.txt
Append stdout to a file
cmd 2>&1 | less
Merge stderr into stdout, then page
cmd &
Run command in the background
!!
Repeat the last command
sudo !!
Re-run the last command as root
pbcopy and pbpaste let you pipe text in and out of the clipboard — e.g. cat file.txt | pbcopy.