RubyGems

Package manager for Ruby


    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 gem help:

`commands`	list all 'gem' commands
`examples`	show some examples of usage
`gem_dependencies`	gem dependencies file guide
`platforms`	gem platforms guide
`<COMMAND>`	show help on COMMAND (e.g. 'gem help install')
`gem server`	present a web page at http://localhost:8808/ with info about installed gems

gem install gemname [gemname …] [options] -- --build-flags [options]

Install/Update Options
`--platform platform`	to install
`-v --version version`	of gem to install
`--[no-]prerelease`	Allow prerelease versions of a gem to be installed. (Only for listed gems)
`-i --install-dir dir`	repository directory to get installed gems
`-n --bindir dir`	where binary files are located --[no-]document [TYPES] Generate documentation for installed gems List the documentation types you wish to generate. For example: rdoc,ri
`--build-root dir`	Temporary installation root. Useful for building packages. Do not use this when installing remote gems.
`--vendor`	Install gem into the vendor directory. Only for use by gem repackagers.
`-N --no-document`	Disable documentation generation
`-E --[no-]env-shebang`	Rewrite the shebang `#!` line on installed scripts to use `/usr/bin/env`
`-f --[no-]force`	Force gem to install, bypassing dependency checks
`-w --[no-]wrappers`	Use bin wrappers for executables Not available on dosish platforms
`-P --trust-policy POLICY`	Specify gem trust policy
`--ignore-dependencies`	Do not install any required dependent gems
`--[no-]format-executable`	Make installed executable names match ruby. If ruby is ruby18, foo_exec will be foo_exec18
`--[no-]user-install`	Install in user's home directory instead of `$GEM_HOME.`
`--development`	Install additional development dependencies
`--development-all`	Install development dependencies for all gems (including dev deps themselves)
`--conservative`	Don't attempt to upgrade gems already meeting version requirement
`--minimal-deps`	Don't upgrade any dependencies that already meet version requirements
`--[no-]post-install-message`	Print post install message
`-g --file [FILE]`	Read from a gem dependencies API file and install the listed gems
`--without groups`	Omit the `groups (comma separated) when installing from a dependencies file`
`--default`	Add full specification to specifications/default and extract only its bin
`--explain`	indicate which would be installed
`--[no-]lock`	Create a lock file (when used with `-g/--file)`
`--[no-]suggestions`	Suggest alternates when gems are not found
Local/Remote Options:
`-l --local`	Restrict operations to the LOCAL domain
`-r --remote`	Restrict operations to the REMOTE domain
`-b --both`	Allow LOCAL and REMOTE operations
`-B --bulk-threshold count`	Threshold for switching to bulk synchronization (default 1000)
`--clear-sources`	Clear the gem sources
`-s --source URL`	Append URL to list of remote gem sources
`-p --[no-]http-proxy [URL]`	Use HTTP proxy for remote operations
Common Options:
`-h --help`	Get help on this command
`-V --[no-]verbose`	Set the verbose level of output
`-q --quiet`	Silence commands
`--config-file FILE`	Use this config file instead of default
`--backtrace`	Show stack backtrace on errors
`--debug`	Turn on Ruby debugging
`--norc`	Avoid loading any .gemrc file
Deprecated Options
`--[no-]rdoc`	Generate RDoc for installed gems Use --document instead
`--[no-]ri`	Generate ri data for installed gems. Use --document instead
`-u --[no-]update-sources`	Update local source cache

Arguments: GEMNAME name of gem to install

: Install a gem into the local repository

For gems with executables ruby installs a wrapper file into the executable directory by default. This can be overridden with the --no-wrappers option. The wrapper allows you to choose among alternate gem versions using _version_.

For example `rake _0.7.3_ --version` will run rake version 0.7.3 if a newer version is also installed.

Gem Dependency Files

RubyGems can install a consistent set of gems across multiple environments using `gem install -g` when a gem dependencies file (gem.deps.rb, Gemfile or Isolate) is present. If no explicit file is given RubyGems attempts to find one in the current directory.

When the RUBYGEMS_GEMDEPS environment variable is set to a gem dependencies file the gems from that file will be activated at startup time. Set it to a specific filename or to "-" to have RubyGems automatically discover the gem dependencies file by walking up from the current directory.

Enabling automatic discovery on multiuser systems can lead to execution of arbitrary code when used from directories outside your control.

Extension Install Failures

If an extension fails to compile during gem installation the gem specification is not written out, but the gem remains unpacked in the repository. You may need to specify the path to the library's headers and libraries to continue. You can do this by adding a -- between RubyGems' options and the extension's build options:

      $ gem install some_extension_gem
      [build fails]
      Gem files will remain installed in \
      /path/to/gems/some_extension_gem-1.0 for inspection.
      Results logged to /path/to/gems/some_extension_gem-1.0/gem_make.out
      $ gem install some_extension_gem -- --with-extension-lib=/path/to/lib
      [build succeeds]
      $ gem list some_extension_gem
    
      *** LOCAL GEMS ***
    
      some_extension_gem (1.0)

If you correct the compilation errors by editing the gem files write the specification by hand. For example:

 $ gem install some_extension_gem
      [build fails]
      Gem files will remain installed in \
      /path/to/gems/some_extension_gem-1.0 for inspection.
      Results logged to /path/to/gems/some_extension_gem-1.0/gem_make.out
      $ [cd /path/to/gems/some_extension_gem-1.0]
      $ [edit files or what-have-you and run make]
      $ gem spec ../../cache/some_extension_gem-1.0.gem --ruby > \
                 ../../specifications/some_extension_gem-1.0.gemspec
      $ gem list some_extension_gem
    
      *** LOCAL GEMS ***
    
      some_extension_gem (1.0)

Defaults:

--both --version '>= 0' --document --no-force --install-dir /home/realger1/ruby/gems --lock

guides.rubygems.org