Writing code on the iPad

Disclaimer

This short guide will imply jailbreaking the iPad, using the command line (I will need a full-fledged computer to make it) and some SSH fiddling. If this makes anyone uncomfortable then please leave.
I wrote the guide for me as a memento long ago and that implies I’ve got some experience in *NIX systems and am willing to make some Googling to find creative solutions. Be advised.
Current iOS version at the time of this writing is 7.0.4 and I’ve applied this guide with success to an iPad Air and a first version iPad Mini (the non-retina version).

Why

I’ve got the iPad almost always with me and since I enjoy coding I’d like to be able to do so efficiently anywhere. Using Test-driven development techniques to do so I do not want to just write code but to be able to test it too. On the same machine I write it possibly.

The end result

The result of this short guide is being able to edit code using vim text editor or any other code IDE for iPad, pull and push modifications to the code using command line git and, optionally, running PHPUnit tests via the command line (I’m a PHP developer).
It’s not that the iPad lacks good code editors but they all lack, due to Apple sandboxing limitations, the power to interoperate efficiently one with the other; when I say “efficiently” I mean I can do it using an external keyboard at about the same speed I can work on my MacBook Pro.

Jailbreaking and requirements

First step into this adventure is jailbreaking the iPad itself. I’ve used evasi0n tool to do so and that’s as easy as pushing a button. Litterally.
As easy as supporting the project.
Once the jailbreaking is done a new Cydia app icon will appear on the springboard. I’m not delving into details here but I’ve installed the OpenSSH package to be able to remotely login into the iPad.

De-sandboxing applications via SSH

To actually work on the iPad I will use vim code editor and to usevim I will need to be able to access the terminal. I will use Prompt app by Panic to log into the local host address 127.0.0.1; trying this now would result in an error that’s simply the app “hitting the walls of its sandbox container”: I have to give the app root privileges moving it to the same place other Apple (read “system”) applications reside.
I will find the location of the Prompt.app package

cd /var/mobile/Applications
find . -name Prompt.app

to get the name of the folder, a long alpha-numeric string, the app has been installed into and then move the app “executable” among the non-sandboxed applications

cd E86861F7-1DC0-40BF-82BD-28FF9491422B/  <<< insert the folder found with the find command
mv Prompt.app/ /Applications

I will now open the iPad and delete the Prompt.app icon as if to uninstall it. After that, getting back to the SSH shell and refresh the springboard as the mobile user

su mobile
uicache

After that the Prompt app icon will be back on the springboard and will now be able to connect to the localhost address.
The same principle really applies to any app.

Install PHP

Since I will use PHP version 5.4.* to work I will add a repository source to cydia and that will be the iOs-Webstack one. After that I will install the PHP54 package from iOs-Webstack repository.

Install aptitude package manager (optional)

I will install aptitude via Cydia to be able to download packages via the command line. Any package I install via the command line, either via an SSH session or the Prompt app, can be installed using Cydia UI.

Install vim and git

Using SSH I will type the command

su -                                <<< to get back to the root user, will request password
aptitude install vim git wget curl coreutils coreutils-bin

and that’s all.

Create SSH keys to be able to use GitHub

Distributed version control is a must for me and almost any one using a computer for anything beyond social networks will need to use git and/or GitHub. Sadly that can’t be done out of the box when it comes to pulling and pushing from/to GitHub repositories due to missing SSL certificates.
As detailed on GitHub help page I will generate a private and public keys using SSH

ssh-keygen -t rsa -C "[email protected]"

and answer to the generator response for a key location, I will use the default one, and a passphrase. Following along GitHub guidelines I will print the public key contents to screen to be able to copy and paste them to GitHub (this I will do via SSH and a real PC)

cat ~/.ssh/id_rsa.pub

and will follow the guide from that point.
Please note that this set up will allow for repository cloning via SSH and not the “usual” way.

Install PHPUnit

I will usually install PHPUnit using pear but since I’m working in a reduced enviroment here I will just download phpunit.phar file and move it to the executables directory

wget --no-check-certificate https://phar.phpunit.de/phpunit.phar
chmod +x phpunit.phar
mv phpunit.phar /usr/local/bin/phpunit

running

phpunit --version

from the command line will yield PHPUnit version information.

Expand and extend

Now that I’ve got the tools and know-how I can extend the iPad possibilities and common pitfalls. No need to wait for an iPad Pro when a current jailbroken iPad will give me almost 10 hours of portable and local programming environment.

But I hate vim!

No, I love it but I believe anyone has the right to choose its tools and vim is not an option when there isn’t a keyboard connected to the iPad; I’m not that masochist.
In those cases I will use another iPad coding IDE app and after I’ve created a symbolic link to its Documents folder in the root user home folder (/var/root); I’m doing this for Textastic here

find /var/mobile/Applications -name Textastic.app

after the folder containing Textastic has been found

ln -s /var/mobile/Applications/5831B796-F4AF-4F9C-8F4A-A5A7B49750CE/Documents/ /var/root/Documents

and now editing any file in the /var/root/Documents folder will show into Textastic.
I will pull and push git repositories in the /var/root/Documents folder and those will magically appear in Textastic documents.

I appreciate your input