Command line Cheat Sheet

This is a generic/intro guide to the bash shell.

The reason for this is to provider relatively new coders with a simple reference to the command-line.

General Notes/Tips

Press tab after typing a few letters for tab-completion.
If you're on a Mac, iTerm is a better terminal to use.
The \ backslash is used to write a command across multiple lines (for readability).

Open New Terminal Tab from Command-line on Mac

osascript -e 'tell application "Terminal" to activate' -e 'tell application "System Events" to tell process "Terminal" to keystroke "t" using command down'

File System Commands

Print Current Directory

pwd

Print directory structure

find . -print | sed -e 's;[^/]*/;|____;g;s;____|; |;g'

But better, install this: http://mama.indstate.edu/users/ice/tree/

Changing Directories

cd ./packages
cd packages

List Files in Directory

ls

Moving Files

mv packages lib

Copying Files and Directories

cp ./lib/tower.js ./tmp/tower.js

Create a File

touch ./tmp/tower.js

Create a directory

mkdir ./tmp
# make nested directories
mkdir ./tmp/The\ Beatles\White\ Album\ Disc\ 1

Removing Files and Directories

rm -rfv ./tmp

Symlinking Files

Make a file "executable"

chmod 755 ./bin/tower

Append content to a file

Replace content in a file

Searching files

Inspecting a File's Metadata

# on Mac
mdls ./bin/tower

Mac Spotlight actually uses that information when you search.

Unzipping a File

Zipping a File

Open a File

open ./bin/tower

Open current directory

open .

If you put this command in your ~./bash_profile it will open that file when you start your computer.

HTTP Commands

Downloading Files

# `L`: follow redirect if server is throwing some intermediate redirect.
# `O`: save as local file(s) rather than sending to STDOUT.
curl -L https://github.com/downloads/viatropos/tower/tower.png -O

Uploading Files

curl -X POST \
  -F attachment[files][]="[@some/image.png;type=image/png" \
  http://localhost:3000/attachments.json

GET JSON

curl -H "Accept: application/json" -H "Content-type: application/json" \
  http://localhost:3000/posts.json

POST JSON

curl -H "Accept: application/json" -H "Content-type: application/json" \
  -X POST \
  -d '{"post":{"title":"A Post!"}}' \
  http://localhost:3000/posts.json

PUT JSON

curl -H "Accept: application/json" -H "Content-type: application/json" \
  -X PUT \
  -d '{"post":{"title":"New Title"}}' \
  http://localhost:3000/posts/301860cb52ad676200000003.json

DELETE JSON

curl -H "Accept: application/json" -H "Content-type: application/json" \
  -X DELETE \
  http://localhost:3000/posts/301860cb52ad676200000003.json

Downloading a Website

wget  -r -e robots=off --wait 0.25 --random-wait -N --user-agent "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_7) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.56 Safari/536.5" "http://example.com/"

Downloading Large (or Lots) of Files

You can use rsync, but I would use rsync through wget:

wget

Simulating Web Traffic (Load Testing)

Apache bench.

ab -n 1000 -c 5 http://localhost:3000/posts.json

Login to Remote Command-line

ssh username@hostname

System Commands

Show Operating System Version

uname -a

Show Your IP Address

ifconfig

See your most recent commands

history

...and make aliases for them:

history | awk '{print $2}' | awk 'BEGIN {FS="|"} {print $1}' | sort | uniq -c | sort -r

Print IP Address

Show executable path

which tower

List Processes

ps -ax

Kill a Process

Logging

tail -n 500
top

Limits

ulimit -n 10240

Take a snapshot

# Mac:
screencapture -iW ~/Desktop/screen.jpg  # currently focused window
screencapture -S ~/Desktop/screen.jpg   # entire desktop

Copy to clipboard

# copies the directory listing
ls -l | pbcopy

Paste from clipboard

# get pasteboard lines containing foo and save them in a_file
pbpaste | grep foo > a_file

Shell Variables

Environment Variables

Custom Variables

Pipes

Filters

Keyboard Events

File System Events

Configuring the Shell

`~/.bash_profile`

`~/.bashrc`

`~/.profile`

Command Summary

sed
awk
grep
find
which
chmod
curl
wget
touch
cp
cd
pwd
ls
kill
ps
wc
cat
echo
ping
sudo
history
alias
sort
uniq
open

Random Useful Mac Commands

# eject disk
drutil tray open
# open movie with vlc
open -a vlc movie.avi

Useful Command-line Tools

pdftotext
brew
git
ImageMagick