linux下安装ruby的mysql库

运行以下代码安装ruby的mysql库:

sudo gem install mysql

结果报以下错误:

Building native extensions.  This could take a while...
ERROR:  While executing gem ... (Gem::Installer::ExtensionBuildError)
    ERROR: Failed to build gem native extension.

ruby extconf.rb install mysql
extconf.rb:1:in `require': no such file to load -- mkmf (LoadError)
        from extconf.rb:1

上网一搜，原来需要先安装ruby-dev:

sudo apt-get install ruby1.8-dev

再运行:

sudo gem install mysql

OK了。