I need to add the following lines to the end of .bashrc file in Ubuntu.
file, is there some refresh command to be able immediately use the new aliases or functions without closing the terminal (in my case xfce4-terminal with a few tabs open, many files open and in the middle of the work)?
"you will have to run this in every instance." - Note that zsh users can set TMOUT and TRAPALRM appropriately to stat and (if necessary) re-source ~/.zshrc once per second, or at any other reasonable interval.
But of course, it's not effective in any programs or scripts called by the calling program.
To make it effective all the way down the call chain, you must follow the setting of the environment variable with an export command.