Sometime when you modify .bashrc or .bash_profile and source it, you may notice that you have ‘lost’ your shell commands.
You will see ‘command not found’ for the simplest commands such as ls and which.
Most like this happens because you have accidentally override your PATH. So instead of doing:
PATH=my/custom/path:$PATH, you did PATH=my/custom/path.
Here’s a simpel way to fix it.
echo 'PATH=/bin:/usr/bin' > foo && source foo
This will get recover your commands so you can modify your .bashrc or .bash_profile with nano. Remember to back up a working version before working on them next time :)