Ruby: What's RVM, Gem, Rake, Bundler, RDoc, ri, irb?
This page shows you how to install Ruby on linux, and explains essential tools used in Ruby. It is NECESSARY to be familiar with these tools if you work with Ruby or Rails.
What is “irb”?
“irb” is the interactive command line interface for Ruby.
“irb” is written in Ruby.
Type irb --help. Sample output: irb_help.txt
.
Type irb to start. Type exit or press
Ctrl+d to quit.
What is “ri”?
“ri” is Ruby's doc reader, similar to unix man or perl's perldoc or python's pydoc.
“ri” is written in Ruby.
Type ri --help. Sample output: ri_help.txt
.
What is “gem”?
RubyGems is a tool for installing/managing Ruby packages. It's similar to linux's apt-get.
Each Ruby package in the RubyGem format is called “gem”. A Ruby package (library) is usually also called a “gem”.
RubyGems is now part of the standard library from Ruby version 1.9.2.
RubyGems is written in Ruby.
The command name is gem. Type gem --version and gem --help. Sample output: gem_help.txt
◆ gem --help
RubyGems is a sophisticated package manager for Ruby. This is a
basic help message containing pointers to more information.
Usage:
gem -h/--help
gem -v/--version
gem command [arguments...] [options...]
Examples:
gem install rake
gem list --local
gem build package.gemspec
gem help install
Further help:
gem help commands list all 'gem' commands
gem help examples show some examples of usage
gem help platforms show information about platforms
gem help <COMMAND> show help on COMMAND
(For example, 'gem help install')
gem server present a web page at
http://localhost:8808/
with info about installed gems
Further information:
http://rubygems.rubyforge.org
For example, try gem list to list locally installed gems.
What is Rake?
“Rake” is short of “Ruby Make”.
Rake is a tool, similar to unix make. It reads a file of dependency spec, and call other commands to build things or run tasks.
Rake is now part of the standard library from Ruby version 1.9.
Rake is written in Ruby.
Type rake --help. Sample output: rake_help.txt
◆ rake --help
rake [-f rakefile] {options} targets...
Options are ...
--backtrace=[OUT] Enable full backtrace. OUT can be stderr (default) or stdout.
--comments Show commented tasks only
--job-stats [LEVEL] Display job statistics. LEVEL=history displays a complete job list
--rules Trace the rules resolution.
--suppress-backtrace PATTERN Suppress backtrace lines matching regexp PATTERN. Ignored if --trace is on.
-A, --all Show all tasks, even uncommented ones
-D, --describe [PATTERN] Describe the tasks (matching optional PATTERN), then exit.
-e, --execute CODE Execute some Ruby code and exit.
-E, --execute-continue CODE Execute some Ruby code, then continue with normal task processing.
-f, --rakefile [FILE] Use FILE as the rakefile.
-G, --no-system, --nosystem Use standard project Rakefile search paths, ignore system wide rakefiles.
-g, --system Using system wide (global) rakefiles (usually '~/.rake/*.rake').
-I, --libdir LIBDIR Include LIBDIR in the search path for required modules.
-j, --jobs [NUMBER] Specifies the maximum number of tasks to execute in parallel. (default:2)
-m, --multitask Treat all tasks as multitasks.
-n, --dry-run Do a dry run without executing actions.
-N, --no-search, --nosearch Do not search parent directories for the Rakefile.
-P, --prereqs Display the tasks and dependencies, then exit.
-p, --execute-print CODE Execute some Ruby code, print the result, then exit.
-q, --quiet Do not log messages to standard output.
-r, --require MODULE Require MODULE before executing rakefile.
-R, --rakelibdir RAKELIBDIR, Auto-import any .rake files in RAKELIBDIR. (default is 'rakelib')
--rakelib
-s, --silent Like --quiet, but also suppresses the 'in directory' announcement.
-t, --trace=[OUT] Turn on invoke/execute tracing, enable full backtrace. OUT can be stderr (default) or stdout.
-T, --tasks [PATTERN] Display the tasks (matching optional PATTERN) with descriptions, then exit.
-v, --verbose Log message to standard output.
-V, --version Display the program version.
-W, --where [PATTERN] Describe the tasks (matching optional PATTERN), then exit.
-X, --no-deprecation-warnings Disable the deprecation warnings.
-h, -H, --help Display this help message.
What is Bundler, bundle?
Bundler is tool similar to RubyGem, except it's specific for a app. That is, it install Ruby packages (gems) specific for your application, based on a dependency file named Gemfile (so, in this respect, it's also similar to Rake or unix “make”). It is heavily used by Rails.
Bundler home page: http://gembundler.com/
Here's a sample Gemfile: Gemfile_sample.txt
The command for Bundler is “bundle”. Type bundle --help.
BUNDLE(1) BUNDLE(1)
NAME
bundle - Ruby Dependency Management
SYNOPSIS
bundle COMMAND [--no-color] [--verbose] [ARGS]
DESCRIPTION
Bundler manages an application's dependencies through its entire life
across many machines systematically and repeatably.
See the bundler website http://gembundler.com for information on get-
ting started, and Gemfile(5) for more information on the Gemfile for-
mat.
OPTIONS
--no-color
Prints all output without color
--verbose
Prints out additional logging information
BUNDLE COMMANDS
We divide bundle subcommands into primary commands and utilities.
PRIMARY COMMANDS
bundle install(1) bundle-install.1.html
Install the gems specified by the Gemfile or Gemfile.lock
bundle update(1) bundle-update.1.html
Update dependencies to their latest versions
bundle package(1) bundle-package.1.html
Package the .gem files required by your application into the
vendor/cache directory
bundle exec(1) bundle-exec.1.html
Execute a script in the context of the current bundle
bundle config(1) bundle-config.1.html
Specify and read configuration options for bundler
UTILITIES
bundle check(1)
Determine whether the requirements for your application are
installed and available to bundler
bundle list(1)
Show all of the gems in the current bundle
bundle show(1)
Show the source location of a particular gem in the bundle
bundle outdated(1)
Show all of the outdated gems in the current bundle
bundle console(1)
Start an IRB session in the context of the current bundle
bundle open(1)
Open an installed gem in the editor
bundle viz(1)
Generate a visual representation of your dependencies
bundle init(1)
Generate a simple Gemfile, placed in the current directory
bundle gem(1)
Create a simple gem, suitable for development with bundler
bundle platform(1)
Displays platform compatibility information
OBSOLETE
These commands are obsolete and should no longer be used
o bundle lock(1)
o bundle unlock(1)
o bundle cache(1)
Bundler is written in Ruby.
What is RDoc?
Rdoc is Ruby's doc generating tool. Similar to Java's javadoc. It extract class/method names and or special comments from Ruby source code and generate to a output format (For example, ri format).
Type rdoc --help. Sample output: rdoc_help.txt
.
RDoc is written in Ruby.
What is RVM?
RVM is Ruby Version Manager. It is used to install Ruby, and also manage multiple installations of Ruby.
It is recommended that you install Ruby by compiling the source code, or use RVM.
RVM is written in bash.
The command of RVM is rvm.