使用 source.bashrc 后别名未更新

Question

I am testing the bash behavior on login (terminal 1), but I got confused about its interaction with alias:

I opened with vim.bashrc and add this line:

alias ls='ls -l'

and save it with :x then I used source.bashrc to simulate a new login session and I found it in the aliases list

But I removed the alias from.bashrc and use source.bashrc again I saw that alias ls='ls -l' was still available. On the other hand, opening new shell terminal (terminal 2) the problem was solved.

Question: Why alias ls='ls -l' was not removed on the first terminal?

Answer 1

Sourcing .bashrc doesn't clear what you have defined so far. It just adds the definitions it contains to your current environment.

If you want to undefine a given alias, just type:

$ unalias ls
$ source .bashrc

If you want to undefine all aliases:

$ unalias -a
$ source .bashrc

Finally, if you want to start over with a brand new shell, you can of course close your session and reopen one, but here is an almost identical command in case this is not that easy (ssh) or undesirable:

$ exec bash

(you may also add the -l option to simulate a login shell, thus reading your ~/.bash_profile file)