CODEWITHSUNDEEP
ruby
André Shevantes
André Shevantes

Reputation: 449

Where to find the ruby executable documentation?

I was trying to find the list of command-line arguments available for the ruby executable in http://ruby-doc.com/ but I could not find anything. After a Google search for "ruby interpreter command line options" I could only find this page, which applies to Ruby 1.4 only. Where can I find the documentation for the ruby executable in an 'official' source, like ruby-doc.com? Thanks!

Upvotes: 0

Views: 127

Answers (2)

Jörg W Mittag
Jörg W Mittag

Reputation: 369428

There is no such thing as "the Ruby executable". Every Ruby implementation has their own commandline executable. (Actually, come to think of it, SmallRuby and BlueRuby didn't have a commandline executable at all.)

And every Ruby implementation has their own commandline flags. That's why there cannot be a document explaining all the options: which implementation's options would that document?

For example, JRuby's --jdb flag to run under the Java Debugger simply doesn't make sense for IronRuby, Rubinius, MacRuby, Topaz, Cardinal, MRuby, or YARV. Rubinius's flag to turn on the sampling profiler doesn't make sense for implementations that don't have a sampling profiler. Rubinius's flag to turn on the native code JIT compiler doesn't make sense for implementations that don't have a native code JIT compiler. And so on.

However, there are a couple of options that most implementations agree on:

  • -0
  • -a
  • -c
  • -C
  • -d
  • -e
  • -E
  • -F
  • -i
  • -I
  • -l
  • -n
  • -p
  • -r
  • -s
  • -S
  • -T
  • -v
  • -w
  • -W
  • -x

BUT!!!

If you look at MRuby, which is the Ruby implementation written by Yukihiro "matz" Matsumoto, Ruby's creator, which is intended to be a lightweight implementation of the minimum core that can still be called "Ruby", it only supports these options:

  • -b load and execute RiteBinary (mrb) file
  • -c check syntax only
  • -e 'command' one line of script
  • -v print version number, then run in verbose mode
  • --verbose run in verbose mode
  • --version print the version
  • --copyright print the copyright

Of these, -b is clearly implementation specific, and -c, -v, --version, and --copyright have no runtime impact, so we can interpret this as meaning that -e is the only option that must be supported by a conforming Ruby implementation … after all, it is the only option supported by the Ruby implementation written by the only person who can legitimately have a say in what it means to be "a Ruby implementation".

Upvotes: 1

Nic Nilov
Nic Nilov

Reputation: 5156

Easiest option is to run man ruby. It will show your locally installed interpreter options.

Definitive option is the ruby repository on GitHub. Navigate to the version you need in the releases and locate man/ruby.1 file in the tree. The file contains definitions for CLI arguments.

Example: Ruby 2.3.0 interpreter CLI arguments definitions are here.

Upvotes: 3

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