WordPress pre自动换行默认只支持IE浏览器，要兼容Opera/Firefox/Chrome，可进行如下操作

主题——>自定义——>额外CSS

添加如下内容

pre {    
        font-family: "Courier 10 Pitch", Courier, monospace;
        /* styles to make preformatted text wrap */
        white-space: pre-wrap;       /* css-3 */
        white-space: -moz-pre-wrap;  /* Mozilla, since 1999 */
        white-space: -pre-wrap;      /* Opera 4-6 */
        white-space: -o-pre-wrap;    /* Opera 7 */
        word-wrap: break-word;       /* Internet Explorer 5.5+ */
}

长代码换行显示测试

sudo apt-get -y install ruby2.1 ruby-switch ruby2.1-dev ri2.1 libruby2.1 libssl-dev zlib1g-dev
sudo ruby-switch --set ruby2.1