Scripting

The PocketMage TERMINAL app runs scripts written in Wrench, a lightweight C-like scripting language. Scripts can draw to the E-Ink and OLED displays, handle input, and talk to the rest of the system through the PocketMage library surface.

Wrench is a small interpreted language with a familiar if / while / var syntax. On PocketMage it is embedded inside the TERMINAL app, so every script is a .c file on the SD card that the terminal compiles and runs on demand.

What Wrench is for

Wrench sits one level above a native app. It trades raw performance for convenience:

Automation - script repeated terminal workflows instead of typing them each time
Custom screens - draw to the E-Ink or OLED with a few function calls
Prototyping - test an idea in a script before writing it as a native app
Device control - read the clock, battery, keyboard, and touch sensors from a script

Because scripts run in the TERMINAL app, they already have access to everything the terminal can reach: the displays, the SD card, prompts, and the shared system helpers.

Script lifecycle

Edit - create or open a .c script in TXT, or use the terminal’s editor. Save it to the SD card.
Compile - run brew <script>.c in the TERMINAL app to compile and execute it.
Run - the terminal interprets the script. print() sends output to the terminal buffer, updateTerm() paints it to the OLED.

The example scripts at the top of the page double as runnable tests: Basic Input/Output walks through the whole edit-to-run flow.

Bindings overview

Wrench bindings fall into five groups. The full command list documents every one with parameters, return values, and examples.

Input/output and terminal - print(), updateTerm(), prompt(), boolPrompt(), timePrompt(), datePrompt(), waitForKeypress()
E-Ink display - updateInk(), inkBackground(), inkRect(), inkCircle(), inkText()
OLED display - updateOled(), oledWord(), sysMessage(), oledBackground(), oledRect(), oledCircle(), oledText()
Hardware and system - getKey(), getTouch(), getBattery(), getBatteryVoltage(), setCpuSpeed(), sleep(), getTime(), getDate()
Filesystem - readFile(), writeFile()
General helpers - delay(), toInt(), random()

Language notes

Variables are declared with var and are dynamically typed. var x = "" creates a string; var i = 0 creates an integer.
Strings convert with toInt() where an integer is required.
Control flow uses C-style braces and parentheses.
random(min, max) returns a value in the inclusive range.
delay() is a blocking wait, in milliseconds.