Dear all,

how to reinitialising the environment variable after some alteration have made without restart to machine?
there are many shell command that will do this?
if so, pls show me how?
thanks in advance

Logout of your shell by typing: logout
Then log back in. If your booting into X, then logout of your xsession, and log back in.

are there many commands that will one go reinitialize the whole environment without logout and logout?

export AVARIABLE=aValue

then u r set.

if u changed your .profile [.bash_profile]
u can do ". .profile"

it works for console that u typed that in.

good luck.

if i created a new environment variables in /etc/profile then how to reinitialise them without logout and login the system.
are there any commands that will settle the reinitialising variables?

Define "reinitialise" please.

Do you mean, set them back to the factory defaults?
Or do you mean, how to make your changes take effect in all your shells/programs etc at once.

i would rather define my "reinitialise" as make my changes to take effect in all shells at once. i found that this is quite troublesome to do the logout and logout in order to make thing works. what i am looking for is just a simple shell prompt that will make any changes (i.e. creating new environment variables) to take effect, just as what the effect of after logout and login does. are there shell prompt that will do this kind of favour?
Thanks for helps.

Ok, let me see if I understand this. You have multiple shells open. You make changes to some environment variables (either changing the values or creating new variables). Then you want all of your shells to reflect the new settings. Is that right?

Short answer: To my knowledge, no, there is no single command to update all open shells at once.

Long answer:
1) If you changed these environment variable values in one of your shell files (~/.bashrc, ~/.bash_profile, ~/.cshrc, or whatever), then you can re-source the file. For instance:
source ~/.bash_profile
-or-
. ~/bash_profile

However, that will only update the shell you execute the command in. You will have to re-source the file in every other shell you have open for the changes to take effect. Similarly, you can source the global files in the same way ("source /etc/profile").

2) If you made these changes from the command line, then there's no way to transfer them except by typing them in to the other shells.