I have a following bash prompt string:root@LAB-VM-host:~# echo $PS1${debian_chroot:+($debian_chroot)}\u@\h:\w\$ root@LAB-VM-host:~# hostname LAB-VM-hostroot@LAB-VM-host:~# Now if I change the hostname from LAB-VM-host to VM-host with hostname command, the prompt string for this bash session does not change:root@LAB-VM-host:~# hostname VM-hostroot@LAB-VM-host:~# Is there a way to update hostname part of bash prompt string for current bash session or does it apply only for new bash sessions?
How to change bash prompt string in current bash session?
bash;prompt;hostname
Does Debian really pick up a changed hostname if PS1 is re-exported, as the other answers suggest? If so, you can just refresh it like this:export PS1=$PS1Don't know about debian, but on OS X Mountain Lion this will not have any effect. Neither will the explicit version suggested in other answers (which is exactly equivalent to the above).Even if this works, the prompt must be reset separately in every running shell. In which case, why not just manually set it to the new hostname? Or just launch a new shell (as a subshell with bash, or replace the running process with exec bash)-- the hostname will be updated.To automatically track hostname changes in all running shells, set your prompt like this in your .bashrc:export PS1='\u@$(hostname):\w\$ 'or in your case:export PS1='${debian_chroot:+($debian_chroot)}\u@$(hostname):\w\$ 'I.e., replace \h in your prompt with $(hostname), and make sure it's enclosed in single quotes. This will execute hostname before every prompt it prints, but so what. It's not going to bring the computer to its knees. 