Sandbox

Hello Sandbox!

Every year "sandbox"

Living in a Sandbox is an optional course that aims at exploring the culture of free and open source UNIX-like software and computer hardware from the viewpoint of a small device: the Raspberry Pi. During this course, students will be exposed to historical and technical elements of computing that are nowadays buried under an app centric culture grown in the names of user-friendliness, transparency and deceptive allegories such as the cloud.

New technologies, like smart phones and web services, promise cutting edge technologies and software as a means to empower users with a seemingly endless progression of new digital possibilities. In fact, many of these new services are striking for the many constraints they place (where can this be played, how many \“friends\” can connect, who decides what a remix means and if it can be \“shared\”).

Many of the platforms are themselves built on decades old technologies & software. Sandbox aims to deconstruct the digital black boxes, revealing the hidden (historical) layers of software and system, with the aim of: (1) empowering students through literacy of reading these systems, and (2) encouraging new assemblages to be (strategically) reconstructed.

When people hear the word sandbox, it is very likely that most of them will be thinking of the outdoor playset that consists of a container filled with sand. You probably have seen many already and have possibly played in one as a child. Using sand as medium and a couple of tools, the sandbox opens the door to a world where anything can be pretended and experimented with. For some others though, the sandbox is linked instead to the realm of software. Indeed, and similarly to its analogue counterpart, software sandboxes are used both to provide testing and prototyping environments, as well as to describe how users and processes can be isolated for security purposes. These two approaches play an important role in the development and execution of software. As a matter of fact, whether you are browsing a website, using an app, or working with your favourite digital tool, sandboxes have been and are currently used to enable and allow this action.

Truth is, digital sandboxes are everywhere and it is a bit … problematic. Indeed, stepping out of an analogue sandbox is as easy as dusting off from your clothes the particules left from the imaginary world. The same cannot be said of the digital sandboxes which bits are tightly interleaved with our daily activities and digital diet. Seeing our increasing dependence on software and network infrastructure and in a post-PRISM age, it is becoming urgent to understand how these sandboxes operate and impact production, communication and more generally social dynamics.

The best way to explore these issues is to run your own sandbox! Living in a Sandbox aims to be a platform for:

• Critically (re)defining terms like Sharing, Network, Public/Private
• Understanding the history of networked computation, and an ability to trace to contemporary practices and to make strategic decisions in creating new work

See also

• A Social Shell & Mesh Cookbooks with Michael Murtaugh & Anne Laforet (2014)
• Shadow IT with Aymeric Mansoux (2022)
• Dir Derive (A Situationist Filesystem) with Magnus Lawrie, Margaret Malcolm, Aymeric Mansoux, Installation, Filesystem (2015)

Sandbox protocol

(Soon!)

Command Line Interface (CLI)

Ghost in the Shell

From: https://vvvvvvaria.org/curriculum/In-the-Beginning-...-Was-the-Commandline/READER.html#how-to-work-with-text-commands

Go ahead and start using the command line by opening a terminal application. You’ll see a text interface with a blinking cursor. What happened when you opened the terminal is that it actually opened a so-called shell for you. The shell (sh) is a software which takes your keyboard input and gives it to the computer’s operating system. There are various types of shells but the most common ones are bash (bourne again shell) or zsh.

Essential commands

From: https://pzwiki.wdka.nl/mediadesign/Shell_Cheat_Sheet

From: https://community.linuxmint.com/tutorial/view/244

System Info

date – Show the current date and time
cal – Show this month’s calendar
uptime – Show current uptime
w – Display who is online
whoami – Who you are logged in as
finger user – Display information about user
uname -a – Show kernel information
cat /proc/cpuinfo – CPU information
cat /proc/meminfo – Memory information
df -h – Show disk usage
du – Show directory space usage
free – Show memory and swap usage

Keyboard Shortcuts

Enter – Run the command
Up Arrow – Show the previous command
Ctrl + R – Allows you to type a part of the command you’re looking for and finds it

Ctrl + Z – Stops the current command, resume with fg in the foreground or bg in the background
Ctrl + C – Halts the current command, cancel the current operation and/or start with a fresh new line
Ctrl + L – Clear the screen

command | less – Allows the scrolling of the bash command window using Shift + Up Arrow and Shift + Down Arrow
!! – Repeats the last command
!\$ – Repeats the last argument of the previous command
Esc + . (a period) – Insert the last argument of the previous command on the fly, which enables you to edit it before executing the command

Ctrl + A – Return to the start of the command you’re typing
Ctrl + E – Go to the end of the command you’re typing
Ctrl + U – Cut everything before the cursor to a special clipboard, erases the whole line
Ctrl + K – Cut everything after the cursor to a special clipboard
Ctrl + Y – Paste from the special clipboard that Ctrl + U and Ctrl + K save their data to
Ctrl + T – Swap the two characters before the cursor (you can actually use this to transport a character from the left to the right, try it!)
Ctrl + W – Delete the word / argument left of the cursor in the current line Ctrl + D – Log out of current session, similar to exit

Learn the Commands

apropos subject – List manual pages for subject
man -k keyword – Display man pages containing keyword
man command – Show the manual for command
man -t man | ps2pdf - > man.pdf – Make a pdf of a manual page
which command – Show full path name of command
time command – See how long a command takes

whereis app – Show possible locations of app
which app – Show which app will be run by default; it shows the full path

Searching

grep pattern files – Search for pattern in files
grep -r pattern dir – Search recursively for pattern in dir
command | grep pattern – Search for pattern in the output of command
locate file – Find all instances of file
find / -name filename – Starting with the root directory, look for the file called filename
find / -name “\filename\” – Starting with the root directory, look for the file containing the string *filename*
locate filename** – Find a file called filename using the locate command; this assumes you have already used the command updatedb (see next)
updatedb – Create or update the database of files on all file systems attached to the Linux root directory
which filename – Show the subdirectory containing the executable file called filename
grep TextStringToFind /dir – Starting with the directory called dir, look for and list all files containing TextStringToFind

File Permissions

chmod octal file – Change the permissions of file to ’’octal’’, which can be found separately for user, group, and world by adding: 4 – read (r), 2 – write (w), 1 – execute (x)
Examples:
chmod 777 filename – read, write, execute for all
chmod 755 filename – rwx for owner, rx for group and world

chmod symbolic file – You can also change permissions in symbolic mode.
Examples:
chmod ugo+x filename – to make a file executable
chmod g+w filename – to grant write access to the group
chmod o-r filename – to remove read access to others

u: user
g: group
o: others

r: read
w: write
x: executable

-R: recursively

For more options, see man chmod.

File Ownership

chown – change ownership

chown name_of_new_owner ’’filename’’
chown newuser:newgroup filename – To change ownership of a file to newuser and the group newgroup
chown root:www-data /var/www/html/ – To change ownership of a file to root and the group www-data

Check the current ownership of a file with: ls -l
Check which groups you are in with: groups

File Commands

ls – Directory listing
ls -l – List files in current directory using long format
ls -laC – List all files in current directory in long format and display in columns
ls -F – List files in current directory and indicate the file type
ls -al – Formatted listing with hidden files

cd dir – Change directory to dir
cd – Change to home
mkdir dir – Create a directory dir
pwd – Show current directory

rm name – Remove a file or directory called name
rm -r dir – Delete directory dir
rm -f file – Force remove file
rm -rf dir – Force remove an entire directory dir and all it’s included files and subdirectories (use with extreme caution)

cp file1 file2 – Copy file1 to file2
cp -r dir1 dir2 – Copy dir1 to dir2; create dir2 if it doesn’t exist
cp file /home/dirname – Copy the filename called file to the /home/dirname directory

mv file /home/dirname – Move the file called filename to the /home/dirname directory
mv file1 file2 – Rename or move file1 to file2; if file2 is an existing directory, moves file1 into directory file2

ln -s file link – Create symbolic link link to file
touch file – Create or update file
cat > file – Places standard input into file
cat file – Display the file called file

more file – Display the file called file one page at a time, proceed to next page using the spacebar
head file – Output the first 10 lines of file
head -20 file – Display the first 20 lines of the file called file
tail file – Output the last 10 lines of file
tail -20 file – Display the last 20 lines of the file called file
tail -f file – Output the contents of file as it grows, starting with the last 10 lines

Network

ifconfig – List IP addresses for all devices on the local machine
iwconfig – Used to set the parameters of the network interface which are specific to the wireless operation (for example: the frequency)
iwlist – used to display some additional information from a wireless network interface that is not displayed by iwconfig
ping host – Ping host and output results
whois domain – Get whois information for domain
dig domain – Get DNS information for domain
dig -x host – Reverse lookup host
wget file – Download file
wget -c file – Continue a stopped download

SSH

ssh user@host – Connect to host as user
ssh -p port user@host – Connect to host on port port as user
ssh-copy-id user@host – Add your key to host for user to enable a keyed or passwordless login

User Administration

adduser accountname – Create a new user call accountname
passwd accountname – Give accountname a new password
su – Log in as superuser from current login
exit – Stop being superuser and revert to normal user

Process Management

ps – Display your currently active processes
top – Display all running processes
kill pid – Kill process id pid
killall proc – Kill all processes named proc (use with extreme caution)
bg – Lists stopped or background jobs; resume a stopped job in the background
fg – Brings the most recent job to foreground
fg n – Brings job n to the foreground

Stopping & Starting

shutdown -h now – Shutdown the system now and do not reboot
halt – Stop all processes - same as above
shutdown -r 5 – Shutdown the system in 5 minutes and reboot
shutdown -r now – Shutdown the system now and reboot
reboot – Stop all processes and then reboot - same as above
startx – Start the X system

meta characters

Meta Characters are characters that have special meaning within the terminal

• ~ the tilde stands for the user’s home. cd ~/ change directory to home
• . dot stands for this directory. ls . list this directory
• .. dot dot stands for the parent directory to this directory. cp myfile.jpg .. copy myfile.jpg to the parent directory
• * asterisk is a wildcards which represents zero or more characters ls P*.jpg will list all the files, in the current directory, that begin with P and end with .jpg
• \ backslash it is a literal character. It escape the meta value of the meta-characters and display them only as literal characters. echo Foo \* will output Foo * If \ wasn’t there it would output all the files in that directory.

man pages

man pages are manuals of program. They tells you what the program is, what it can do and how.

man df show the manual for the program df that is used to display the free disk space

Can you find out how to display the output from df in a human readable format?

pipe

A pipes (” | “) sends the output of one program to the input of another program.

echo "my sentence"| wc the echoed sentence “my sentence” is pipped into the program wc which counts the number of lines, words, and characters

write

> Writes the output of a command to a file, rather than to print on terminal.

df > df_output.txt redirect the content of man dfM to a file called df_output.txt

If the said file doesn’t exit it will create it, if it already exists it will overwrite its contents/

append

>> appends the output of a command to a file, without overwriting the original file.

echo 'also add this' >> df_output.txt will add ‘also add this’ to the contents of df_output.txt

package managers

Package managers like apt-get and aptitude (on Debian/Ubuntu Linux distributions) and Homebrew and MacPorts on Mac, allow more (command-line, but not only) programs, than the ones that come with the operating, to be installed on our system.

sudo apt search [app name]
sudo apt install [app name]
sudo apt remove [app name]

Links

• https://hub.xpub.nl/sandbox/ (XPUB4’s server)
• https://hub.xpub.nl/sandbot/ (XPUB3’s server)
• https://hub.xpub.nl/soupboat/ (XPUB2’s server)
• https://pzwiki.wdka.nl/mediadesign/Sandbox (PZI wiki page about the idea of the Sandbox)
• https://www.bleu255.com/~aymeric/dump/aymeric_mansoux-sandbox_culture_phd_thesis-2017.pdf (Aymeric’s PhD Thesis “Sandbox Culture, A Study of the Application of Free and Open Source – Software Licensing Ideas to Art and Cultural Production”
• https://vvvvvvaria.org/curriculum/In-the-Beginning-...-Was-the-Commandline/READER.html#how-to-work-with-text-commands (In the Beginning … Was the Commandline, reader publishing by Varia (2018))
• https://pzwiki.wdka.nl/mediadesign/Shell_Cheat_Sheet (shell cheat sheet)
• https://solarpunk.cool/zines/map-is-the-territory/ (The Map is the Territory, shell introduction zine by Zach Mandeville (https://coolguy.website/) and Angelica Blevins (https://angblev.com/) from https://solarpunk.cool/; sources of the zine: https://git.sr.ht/~zim/map-is-the-territory)