参见 http://www.rubygems.org/read/chapter/11 并指定一个定义 gemhome 变量的 ~/.gemrc.

See http://www.rubygems.org/read/chapter/11 and specify a ~/.gemrc which defines a gemhome variable.

例如:

gemhome: /usr/local/rubygems

你也可以把这个文件放在/etc/gemrc

You can also place this file in /etc/gemrc

或者，您可以设置 GEM_HOME 环境变量:

Alternatively you can set the GEM_HOME env-variable:

$ export GEM_HOME=/tmp/gemtest
$ gem install bundler
$ ls /tmp/gemtest/bin/
bundle

更新(10 年后):

Andrey Rodionov 下面建议使用

Andrey Rodionov below suggest using

gem: --bindir /usr/bin