如何在Ubuntu中使用gems ?

I recently upgraded to Ubuntu 9.04 and I have issues using gems. I installed Ruby, Rubygems and Rails using apt-get. The rails command does work.

我最近升级到Ubuntu 9.04，在使用gems时遇到了问题。我使用apt-get安装了Ruby、Rubygems和Rails。rails命令可以工作。

I then installed capistrano and other gems, such as heroku. In order to do that, I used the command:

然后我安装了capistrano和其他宝石，比如heroku。为了做到这一点，我使用了以下命令:

sudo gem install XXX

When I want to use the cap command it does not work:

当我想使用cap命令时，它不起作用:

bash: cap: command not found

It is the same with the other gem commands.

它与其他gem命令是一样的。

Do I have something particular to do so that the gem commands work?

我有什么特别的事情要做，以使gem命令工作?

5 个解决方案

#1

Where are my Gems?

You can find where your gems are stored using the gem environment command. For example:

您可以使用gem环境命令找到您的gem存储在哪里。例如:

chris@chris-laptop:~$ gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 1.3.2

  - RUBY VERSION: 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]
  - INSTALLATION DIRECTORY: /usr/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/bin/ruby1.8
  - EXECUTABLE DIRECTORY: /usr/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-linux
  - GEM PATHS:
     - /usr/lib/ruby/gems/1.8
     - /home/chris/.gem/ruby/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:

If you look at the "GEM PATHS:" section you can see that gems can be stored in two places on my laptop: /usr/lib/ruby/gems/1.8 or in the .gem directory in my home dir.

如果您查看“GEM路径:”一节，您可以看到gems可以存储在我的笔记本上的两个位置:/usr/lib/ruby/gems/1.8，或者在我的home dir中的. GEM目录中。

You can also see that executables are stored in EXECUTABLE DIRECTORY which in this case is /usr/bin.

您还可以看到可执行文件存储在可执行目录中，在本例中是/usr/ bin。

Because /usr/bin is in my path this lets me run cap, merb, rails etc.

因为/usr/bin在我的路径中这让我运行cap, merb, rails等。

Updating your PATH

If for some reason your EXECUTABLE DIRECTORY isn't on your path (for example if it is /var/lib/gems/1.8/bin) then you need to update your PATH variable.

如果由于某种原因，可执行目录不在路径上(例如，如果它是/var/lib/gems/1.8 bin)，那么需要更新路径变量。

Assuming that you are using the bash shell. You can do this quickly for the current session by typing the following at the shell prompt; let's pretend that you want to add /var/lib/gems/1.8/bin to the path:

假设您正在使用bash shell。通过在shell提示符下输入以下内容，可以快速完成当前会话;假设您想要在路径中添加/var/lib/gems/1.8/bin:

export PATH=$PATH:/var/lib/gems/1.8/bin

and press return. That appends the new directory to the end of the current path. Note the colon between $PATH and /var/lib/gems/1.8/bin

并按返回。将新目录附加到当前路径的末尾。注意$PATH和/var/lib/gems/1.8/bin之间的冒号

To set the value for all sessions you will need to edit either your .profile or .bashrc file and add the same line to the end of the file. I usually edit my .bashrc file for no reason other than that's what I've always done. When finished, save the file and then refresh your environment by typing:

要设置所有会话的值，需要编辑.profile或.bashrc文件，并在文件末尾添加相同的行。我通常编辑我的。bashrc文件，没有别的原因，除非我一直这样做。完成后，保存文件，然后输入:

bash

at the shell prompt. That will cause the .bashrc to get reread.

在shell提示符。这会导致。bashrc重新读取。

At any point you can check the current value of $PATH by typing

在任何时候，您都可以通过输入来检查$PATH的当前值

echo $PATH

at the shell prompt.

在shell提示符。

Here's a sample from one of my own servers, where my username is "chris" and the machine name is "chris-laptop":

这是我自己服务器的一个示例，我的用户名是“chris”，机器名是“chris-laptop”:

chris@chris-laptop:~$ 
chris@chris-laptop:~$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
chris@chris-laptop:~$ 
chris@chris-laptop:~$ export PATH=$PATH:/var/lib/gems/1.8/bin
chris@chris-laptop:~$ 
chris@chris-laptop:~$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/var/lib/gems/1.8/bin
chris@chris-laptop:~$ 

My Gem won't load!

"Ruby gems won't load even though installed" highlights a common problem using multiple different versions of Ruby; Sometimes the Gem environment and Gem path get out of sync:

“Ruby gems不会加载，即使安装”突出了使用多个不同版本的Ruby的常见问题;有时创业板环境和创业板路径不同步:

rb(main):003:0> Gem.path

=> ["/opt/ruby1.9/lib/ruby1.9/gems/1.9.1"]
irb(main):004:0> exit

Any Ruby process here is looking only in one place for its Gems.

这里的任何Ruby进程都只在一个地方寻找它的精华。

:~/$ gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 1.3.7
  - RUBY VERSION: 1.9.1 (2009-05-12 patchlevel 129) [x86_64-linux]
  - INSTALLATION DIRECTORY: /opt/ruby1.9/lib/ruby/gems/1.9.1
  - RUBY EXECUTABLE: /opt/ruby1.9/bin/ruby1.9
  - EXECUTABLE DIRECTORY: /opt/ruby1.9/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /opt/ruby1.9/lib/ruby/gems/1.9.1
     - /home/mark/.gem/ruby/1.9.1
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

Look carefully at the output of gem environment:

仔细查看gem环境的输出:

  - GEM PATHS:
     - /opt/ruby1.9/lib/ruby/gems/1.9.1

This isn't the same path as returned by Gem.path:

这与Gem.path返回的路径不同。

["/opt/ruby1.9/lib/ruby1.9/gems/1.9.1"]

It's hard to say what exactly caused lib/ruby to change to lib/ruby1.9 but most likely the developer was working with multiple Ruby versions. A quick mv or ln will solve the problem.

很难说到底是什么原因导致lib/ruby更改为lib/ruby1.9，但最有可能的是开发人员正在使用多个ruby版本。一个快速的mv或ln将解决这个问题。

If you do need to work with multiple Ruby versions then you really should be using rvm.

如果您确实需要使用多个Ruby版本，那么您确实应该使用rvm。

#2

As noted by @Chris you need to add the gems environment to your path. You can do this by:

正如@Chris指出的，您需要将gems环境添加到路径中。你可以这样做:

echo 'export PATH=$PATH:/var/lib/gems/1.8/bin' | tee --append ~/.bashrc

#3

The folder in which gems are stored must be on your PATH, for example mine is:

存储宝石的文件夹必须在您的路径上，例如我的文件夹是:

/home/victor/.gem/ruby/1.8/bin

/home/victor/.gem/ruby/1.8/bin

Check your path by typing

通过输入检查路径

echo $PATH

#4

It seens that when installing rubygems, now in ubuntu 9.04, I have this problem. I noticed that in "gem environment" the executable directory is "/var/lib/gems/1.8/bin", instead of "/usr/bin"... This is a problem with rubygems or with ubuntu 9.04??

在ubuntu 9.04中安装rubygems时，我遇到了这个问题。我注意到在“gem环境”中，可执行目录是“/var/lib/gems/1.8/bin”，而不是“/usr/bin”…这是rubygems还是ubuntu 9.04的问题?

The solution that I encountered is to add "/var/lib/gems/1.8/bin" to my $PATH doing this: export PATH=$PATH:/var/lib/gems/1.8/bin But it don't is saved... how can I save my path?

我遇到的解决方案是将“/var/lib/gems/1.8/bin”添加到我的$路径中，这样做:export PATH=$PATH:/var/lib/gems/1.8/bin，但它没有保存…我该如何拯救我的路?

Thanks...

谢谢……

Resolvi: coloquei o export PATH=$PATH:/var/lib/gems/1.8/bin no ~/.bashrc! =]

代码输出路径=$PATH:/var/lib/gems/1.8/bin no ~/.bashrc!=)

#5

mkmf is part of the ruby1.9.1-dev package. This package contains the header files needed for extension libraries for Ruby 1.9.1. You need to install the ruby1.9.1-dev package by doing:

mkmf是ruby1.9.1-dev包的一部分。这个包包含Ruby 1.9.1扩展库所需的头文件。您需要通过以下步骤安装ruby1.9.1-dev包:

sudo apt-get install ruby1.9.1-dev

sudo apt-get安装ruby1.9.1-dev