ubuntu18.04在换源的时候想打#注释一行代码，却打不出来#，什么也打不出来，怎么解决？

ubuntu18.04在换源的时候想打#注释一行代码，却打不出来#，什么也打不出来，怎么解决？

看看这个
https://blog.csdn.net/Linux_bin/article/details/106193583?ops_request_misc=&request_id=&biz_id=102&utm_term=ubuntu18.04%EF%BC%8C%E6%89%93%E4%B8%8D%E5%87%BA%E6%9D%A5?ops_request_misc=&request_id=&biz_id=102&utm_term=ubuntu18.04%EF%BC%8C%E6%89%93%E4%B8%8D%E5%87%BA%E6%9D%A5&utm_medium=distribute.pc_search_result.none-task-blog-2~all~sobaiduweb~default-0-106193583.142^v42^control,185^v2^tag_show&spm=1018.2226.3001.4449#%E7%AC%A6%E5%8F%B7&utm_medium=distribute.pc_search_result.none-task-blog-2~all~sobaiduweb~default-0-106193583.142^v42^control,185^v2^tag_show