无论golang中CLI中的参数位置如何,都获取文件名

Hello I've been trying to make my own pastebin script to get used to golang,As I was making it, I came across an issue after I tried to get rid of the -f flag that holds the file's name I tried to make it like any regular UNIX command, example ls -la file works the same as ls file -la.

I've reading about flag package in golang, but didn't seem to find anything that can help me fix such a problem. This is my first post here, I searched for similar questions but didn't find any. Thank you