I know that I can set a variable, 'export' the variables and put an alias statement in my .bash_rc file.
When I just set a variable it just lasts for that session and is not visible to other sessions, correct?
Then when I export it it it is visible to other shell sessions (is that only to other 'new' sessions though?
Can existing sessions reload or soemthing to get it?)
Most critically does that export 'stay' through a reboot?
Or is that when the .bashrc file comes in for 'really' permanent setting of variables going forward?
Finally any known differences between Ubuntu and Mac on this?