CheatPress

RubyGems Ruby package manager

Version 4.0.23 · source

RubyGems, Postcard, light preview Light · Postcard 102 × 152 mm · PDF RubyGems, Postcard, dark preview Dark · Postcard 102 × 152 mm · PDF RubyGems, Postcard, ink saver preview Ink saver · Postcard 102 × 152 mm · PDF
RubyGems, A5, light preview Light · A5 148 × 210 mm · PDF RubyGems, A5, dark preview Dark · A5 148 × 210 mm · PDF RubyGems, A5, ink saver preview Ink saver · A5 148 × 210 mm · PDF
RubyGems, A4, light preview Light · A4 210 × 297 mm · PDF RubyGems, A4, dark preview Dark · A4 210 × 297 mm · PDF RubyGems, A4, ink saver preview Ink saver · A4 210 × 297 mm · PDF
RubyGems, A4 landscape, light preview Light · A4 landscape 297 × 210 mm · PDF RubyGems, A4 landscape, dark preview Dark · A4 landscape 297 × 210 mm · PDF RubyGems, A4 landscape, ink saver preview Ink saver · A4 landscape 297 × 210 mm · PDF
RubyGems, A3, light preview Light · A3 297 × 420 mm · PDF RubyGems, A3, dark preview Dark · A3 297 × 420 mm · PDF RubyGems, A3, ink saver preview Ink saver · A3 297 × 420 mm · PDF
RubyGems, A3 landscape, light preview Light · A3 landscape 420 × 297 mm · PDF RubyGems, A3 landscape, dark preview Dark · A3 landscape 420 × 297 mm · PDF RubyGems, A3 landscape, ink saver preview Ink saver · A3 landscape 420 × 297 mm · PDF
RubyGems, Letter, light preview Light · Letter 8.5 × 11 in · PDF RubyGems, Letter, dark preview Dark · Letter 8.5 × 11 in · PDF RubyGems, Letter, ink saver preview Ink saver · Letter 8.5 × 11 in · PDF
RubyGems, Tabloid, light preview Light · Tabloid 11 × 17 in · PDF RubyGems, Tabloid, dark preview Dark · Tabloid 11 × 17 in · PDF RubyGems, Tabloid, ink saver preview Ink saver · Tabloid 11 × 17 in · PDF

Start here

gem install <gem>
Install a gem
gem list
Installed gems
gem search <regexp>
Find gems on the server
gem info <gem>
Details of one gem
gem update
Update installed gems
gem uninstall <gem>
Remove a gem
gem build <name>.gemspec
Package your own gem
gem env
Where gems live

Concepts

  1. Gemspec your gem's metadata
  2. .gem file packaged archive
  3. rubygems.org the default source
  4. GEM_HOME installed gems
  5. Your Ruby code

Install

gem install <gem>
Install the latest version
gem install <gem> -v "~> 1.2"
Install a version matching a constraint
gem install <gem> --user-install
Install into your home directory
Binaries then land in the user gem bin dir; add it to PATH (gem env shows the path).
gem install <gem> --no-document
Skip generating docs (much faster)
gem install <gem> --prerelease
Allow prerelease versions
gem install <gem> -s <url>
Fetch from another source
gem install -g Gemfile
Install the gems a Gemfile lists
gem install <name>.gem
Install a local .gem file
gem install <gem> --conservative
Keep already-installed dependencies
gem fetch <gem>
Download the .gem file without installing
gem exec <cmd>
Run a gem's executable, installing if needed

List & search

gem list
List installed gems
gem list <regexp>
Filter installed gems by name
gem list -d
Include description and details
gem list <gem> -i
Is it installed? Prints true or false
gem search <regexp>
Search remote gems by name
gem search <regexp> -ae
Exact name, all versions
gem list -r <regexp>
List remote gems
gem info <gem>
Version, license, homepage, install path
gem contents <gem>
List an installed gem's files
gem which <file>
Path of a requireable file
gem dependency <gem>
Show a gem's dependencies
gem dependency <gem> -R
Show what depends on it
gem specification <gem>
Show the full gemspec
gem specification <gem> <field>
Show a single gemspec field

Update & remove

gem outdated
List gems with newer versions
gem update
Update all installed gems
Older versions stay installed; run gem cleanup to remove them.
gem update <gem>
Update one gem
gem update --system
Update RubyGems itself
gem update --system <version>
Move RubyGems to a given version
gem uninstall <gem>
Remove a gem
gem uninstall <gem> -v <version>
Remove one version
gem uninstall <gem> -a
Remove all versions without asking
gem uninstall <gem> -x
Also remove its executables
gem uninstall <gem> -I
Ignore dependency checks
gem cleanup
Remove old versions of gems
gem cleanup -n
Dry run: show what would go
gem pristine <gem>
Restore a gem to its packaged state
gem pristine --all
Restore every installed gem
gem stale
Gems by last file access

Sources

gem sources
Show configured sources
gem sources -a <url>
Add a source
gem sources -r <url>
Remove a source
gem sources -u
Refresh the source cache
gem sources -c
Clear the source cache
gem sources --prepend <url>
Add a source at the top

Build & publish

gem build <name>.gemspec
Package a gem into a .gem file
gem build <name>.gemspec -o <file>
Choose the output file name
gem build <name>.gemspec --strict
Fail on gemspec warnings
gem signin
Sign in and store an API key
gem push <name>-<version>.gem
Upload a gem to rubygems.org
gem push <file> --otp <code>
Push with a one-time MFA code
gem push <file> --host <url>
Push to another gem server
gem owner <gem>
List the owners of a gem
gem owner <gem> -a <email>
Add an owner
gem yank <gem> -v <version>
Pull a pushed version from the index
A yank cannot be undone and the version number cannot be reused.
gem signout
Sign out of all sessions
gem unpack <gem>
Extract a gem into the current folder
gem open <gem>
Open a gem's source in your editor
gem rebuild <gem> <version>
Check that a published gem is reproducible

Environment

gem env
Show RubyGems configuration
gem env home
Where gems are installed
gem env gempath
All directories searched for gems
gem env version
RubyGems version
gem env remotesources
Configured remote sources
gem --version
Print the RubyGems version
gem help <command>
Help for one command
gem help commands
List every command
gem check --doctor
Find and clean orphaned gem files
GEM_HOME=<dir> gem install <gem>
Install into a custom directory
Version constraints (-v)
Constraint Meaning
"1.2.3" exactly 1.2.3
">= 1.2" 1.2 or newer
"~> 1.2" 1.2 up to below 2.0
"~> 1.2.3" 1.2.3 up to below 1.3
"< 2" anything below 2

Recipes

Install without docs, per user
gem install <gem> --user-install --no-document# put the user bin dir on PATHgem env gempath
Tidy a gem set
gem outdatedgem updategem cleanup -ngem cleanup
Publish a gem
gem build <name>.gemspecgem signingem push <name>-<version>.gem
Debug a missing gem
gem list <gem>gem which <file>gem env gempathgem pristine <gem>