The environment variable PATH is the search path for executable commands, so I thought changing the PATH to something that doesn't exist (for instance,
export PATH=blah) would make me unable to use any command.
After I change it, it doesn't let me use all commands (e.g. I can't use
ls). But apparently, I can still use numerous commands, and I can still use
export and change it back.
Aren't all commands just executable files in the search path? Where are the executable files for these still-usable commands located? How come I can still use them when my search path is gibberish?