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Old 09-27-2011, 10:28 AM   #1
SilversleevesX
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BASH: Share one variable value between users -- possible?


(Particularly user A -- me -- and root.)

I know it can be done between login shells and subshells, or subshells to the primary running shell, as in a script, with the export command. But is there something similar in BASH (or any part of Linux) for passing a value set to a variable to the same, or a similar, variable that can be "echo-ed" and otherwise used by root, just to give an example?

BZT
 
Old 09-27-2011, 10:47 AM   #2
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Not dynamically.

However what you could do is save the variable from the first session to a file:

Code:
echo $A >var.out
Then in your other session you can set the variable:

Code:
export A=$(cat var.out)
 
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Old 09-28-2011, 01:53 AM   #3
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I am not sure if this will help but may be you can put an export statement in rc.local .
 
Old 09-28-2011, 09:24 AM   #4
MensaWater
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Quote:
Originally Posted by bsat View Post
I am not sure if this will help but may be you can put an export statement in rc.local .
I think the OP was asking if he was already logged in and running a session and set a variable could he then make another already logged in session use that same variable. The answer is no but he can do what I wrote above.

For having all sessions by a single user use the same variable at login he can put them in the user's .bashrc or .bash_profile rather than mucking with rc.local. For all sessions by all bash users he can put it in /etc/bashrc instead.
 
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Old 09-28-2011, 09:32 AM   #5
snooly
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sockets!
 
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Old 09-28-2011, 09:59 AM   #6
MensaWater
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Quote:
Originally Posted by snooly View Post
sockets!
That seems like it would be a bit involved and not really relevant to bash directly. Maybe you have an idea you'd like to expand upon as simply writing "sockets!" to me is about helpful as writing "semaphaores!"?
 
Old 09-28-2011, 10:14 AM   #7
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So basically you're asking if the users can set/modify each others environment variables? Ummm.... No, ofcourse not It would mean that you could mess up somebody's session completely by altering their variables, or even spy on them. For example by directing their shell history to a file that is readable by you.
 
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Old 09-30-2011, 07:37 AM   #8
SilversleevesX
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Post

Quote:
Originally Posted by alienDog View Post
So basically you're asking if the users can set/modify each others environment variables? Ummm.... No, ofcourse not It would mean that you could mess up somebody's session completely by altering their variables, or even spy on them. For example by directing their shell history to a file that is readable by you.
I was thinking of that OL. I thought there might be a security consideration involved (inherent?) in why it couldn't be done. I just couldn't come up with anything specific. Thanks for giving a little focus to it. BZT
 
  


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