Added InterAppCommunication via /dev/iac

[redbug26]

You have also to add TARGET_IS_EXTENSION in "Preprocessor Macros" like in this screen

To test:

# Open iOS Settings
echo "App-prefs:root=General&path=Keyboard" > /dev/iac

# Open music
echo "music:" > /dev/iac

# Test x-callback (available also from any other application.. EG: type the url in safari)
echo "x-ish://x-callback-url/iac?output=username@gmail.com&password=myPassword" >/dev/iac
cat /dev/iac

Could be used to with Shortcut apps via something like

shortcuts://x-callback-url/run-shortcut?name=Calculate%20Tip&input=text&text=24.99&x-success=x-ish%3A%2F%2Fx-callback-url%2Fiac%3fresult

[tbodt]

Thanks for taking the time to implement this! On first look this seems pretty good. One thing I'd want adjusted is the device number, which is currently 1,99. I would want to reserve an entire major number for iSH devices, and define an API for adding custom entries to the array in fs/dev.c. Looking at the list of allocated major numbers, 240 seems like a good choice, since major numbers from 240 to 254 are reserved for devices with no actual official major number. I'll review this a bit more later.

[redbug26]

No problem :)
Working on /proc/net/dev now :)

[saagarjha]

Here's a selection of unsolicited review that I thought you might find useful.

[jthoward64]

What is needed to merge this?