在linux中，如何在终端的任何目录中启动程序（ex.sublime文本）？

I want to do the following thing: In a terminal that is in any directory, type: "sublime a.txt" And sublime text will open a.txt in the current directory. I know i need to somehow write some script but how? One of my friends has done it once but i forgot.I want to do the following thing: In a terminal