mruby-mruby/mrbgems/mruby-bin-mrb

mruby-bin-mrb

mrb is a lightweight mruby runtime that executes only precompiled RiteBinary (.mrb) files. Unlike the full mruby command, it does not depend on mruby-compiler, resulting in a significantly smaller binary.

This gem is intended for embedded deployments where Ruby scripts are precompiled on a development machine and only the runtime is needed on the target device.

Size comparison

By excluding mruby-compiler (and gems that depend on it such as mruby-eval, mruby-binding, and mruby-bin-mirb), the text segment can be reduced by approximately 300KB or more, depending on the build configuration.

Usage

mrb [switches] programfile.mrb [arguments]

Options

• -d - set debugging flags (set $DEBUG to true)
• -r library - load a library (.mrb) before executing your script
• -v - print version number, then run in verbose mode
• --verbose - run in verbose mode
• --version - print the version
• --copyright - print the copyright

Workflow

# On the development machine (with full mruby + mrbc):
mrbc -o program.mrb program.rb

# On the target device (with mrb only):
mrb program.mrb

# Load a precompiled library before the main program:
mrb -r lib.mrb program.mrb

# Pass arguments to the script:
mrb program.mrb arg1 arg2

Build configuration example

To build a minimal mruby with only the mrb runtime:

# build_config/runtime.rb
MRuby::Build.new do |conf|
  conf.toolchain

  # Use a gembox that does not pull in the compiler.
  # For example, the default gembox does not require it.
  conf.gembox 'default'

  # The runtime-only executor (no compiler dependency)
  conf.gem :core => 'mruby-bin-mrb'

  # Do NOT include these (they require mruby-compiler):
  #   conf.gem :core => 'mruby-bin-mruby'
  #   conf.gem :core => 'mruby-bin-mirb'
  #   conf.gem :core => 'mruby-eval'
  #   conf.gem :core => 'mruby-binding'
end

Differences from mruby command

Feature	mruby	mrb
Execute .rb files	yes	no
Execute .mrb files	yes	yes
-e inline code	yes	no
-c syntax check	yes	no
-b force binary mode	yes	not needed (always binary)
Requires mruby-compiler	yes	no

License

MIT License - see the mruby LICENSE file.