Reading and Writing Files

Harucom can save and load files on its flash memory. Since programs and data are stored as files, they persist even after the power is turned off.

Use Ruby’s File class to read and write files.

# Write a file
File.open("/hello.txt", "w") { |f| f.write("Hello!") }

# Read a file
content = File.open("/hello.txt", "r") { |f| f.read(256) }
puts content

Directory Structure

Harucom’s flash memory has the following directories.

/
├── lib/          # Libraries
│   ├── console.rb
│   ├── irb.rb
│   ├── p5.rb
│   └── ...
├── app/          # Command scripts
│   ├── edit.rb
│   ├── run.rb
│   └── ...
├── etc/          # Settings
│   └── env.yml
├── data/         # Data files
│   ├── drums/
│   └── ...
└── system.rb     # Boot script

Directory	Description
/lib/	A place for libraries. Scripts here can be loaded with require.
/app/	A place for command scripts. Scripts saved here can be run as commands from IRB.
/etc/	A place for settings. Settings live in env.yml here.
/data/	Data files such as the drum samples.
/system.rb	A script that runs when Harucom starts up.

You can place files in any directory on Harucom. Feel free to save your own scripts and data files in the root directory /.

Changes to the system scripts persist across a power cycle. A firmware update writes the system files back to their defaults. To return everything to the factory state, see formatting the filesystem.

Running Scripts

Use the run command to execute any script.

irb> run hello.rb

If you specify only a filename, it loads from the root directory /. In this example, /hello.rb is executed.

You can also specify an absolute path including the directory.

irb> run /home/script.rb

Creating Command Scripts

Ruby scripts saved in the /app directory can be run directly as commands from IRB without using the run command. For example, if you create /app/hello.rb, you can run it by simply typing hello in IRB.

irb> edit /app/hello.rb

Enter the following code in the editor and save it.

name = ARGV[0] || "World"
puts "Hello, #{name}!"

Return to IRB and run it as a command.

irb> hello
Hello, World!

irb> hello Harucom
Hello, Harucom!

Arguments after the command name are available as ARGV inside the script.

Commands for working with files, such as ls and cp, are listed in Commands.