使用feh快速设置桌面壁纸
在awesomeWM上设置壁纸是一件很麻烦的事情，我需要修改 rc.lua 中的代码，然后再restart awesomeWM才能设置新的壁纸。
不过最近发现原来通过 feh 就能够快速设置壁纸了。方法为
feh --bg-scale /path/to/wallpaper.png
通过 feh --help 查看feh帮助就会发现它还支持不同的布局方式：
| bg-center FILE | Set FILE as centered desktop background |
| bg-fill FILE | Like --bg-scale, but preserves aspect ratio by zooming the image until it fits. May cut off corners |
| bg-max FILE | Like --bg-fill, but scale the image to the maximum size that fits the screen with black borders on one side |
| bg-scale FILE | Set FILE as scaled desktop background. This will fill the whole background, but the images' aspect ratio may not be preserved |
| bg-tile FILE | Set FILE as tiled desktop background |
