linux下浏览器backspace后退键使能

firefox版：
现在在用的fedora默认firefox，安chrome还会说可能存在各种隐患。。。先说这个吧。
进入设置界面，在地址栏输入：

about:config

搜索backspace，理论上只有一个选项叫：

browser.backspace_action

它的值设为0，即可实现回览需求。
具体如下：

0: Pressing [Backspace] will go back a page in the session history and [Shift]+[Backspace] will go forward. (Default in Windows)

1: Pressing [Backspace] will scroll up a page in the current document and [Shift]+[Backspace] will scroll down. Except Camino that does not implement any behavior for the value 1, which is unmapped. (Default in Linux builds before 2006-12-07)

Any other integer number: Any other integer value will simply unmap the backspace key. In Linux builds after 2006-12-07, the default is 2.

chrome版：
有一个插件在这里：
http://www.chromeextensions.org/appearance-functioning/backspace-as-back-for-linux-2/
参考：
1.http://www.mydigitallife.info/disable-or-enable-backspace-as-go-back-page-browsing-function-in-firefox/