setting a environment variable on linux


 
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# 1  
Old 08-08-2012
setting a environment variable on linux

I want to set a enviroment variable
VDC_DIR to a particular directory.
I am doing it as

Code:
export VDC_DIR=/abc

it gets set but when i logout and do relogin than its not there.
one way could be setting it in .profile file.
but i have seen it on another box where it is not present in .profile but its der in list of env variables.

please tell command to set it as permanent env variable.
# 2  
Old 08-08-2012
Hi
It depends on the default shell of the other box. For bash, it will be in .bash_profile, for tcsh it is .login, for ksh/sh, it is .profile, etc.

Guru.
# 3  
Old 08-08-2012
Well, it could be set up in a number of places.

it is possible to put it in /etc/profile, but I would not recommend that as everyone gets it and eventually /etc/profile get too unweildy. Also if you mess it up, you can't log on and that might make undoing it a little difficult.

Each shell also has it's own startup procedure. For a login to ksh, sh and a few others, they read the .profile in the home directory of the user, then it runs .kshrc. It also runs .kshrc if you spawn a new subshell (i.e. you type ksh on the command line for some reason) For csh, it's .login then .cshrc and there are others too. Can you confirm what shell you are using.

There are also OS specific files you could use, such as /etc/environment, but again everyone will get these, so an error will break it for everyone too.

Another way is to have you PATH set in your .profile to include something that is not generally used but you created, such as /usr/mysite/scripts. If you are in sh, ksh and a few others, you can run a script in there setting the variables you want in such a way that they remain after the script completes:-

Code:
$ cat /usr/mysite/scripts/my-env
export VDC_DIR=/abc

$ echo $VDC_DIR

$ . my-env
$ echo $VDC_DIR
/abc

From a csh, you would use
Code:
$ source my-env


I hope that this helps you get started.

Can you explain a little more about what you are trying to achieve, why and for how many people (and the total user population) and someone will probably recommend one way or another.


Robin
Liverpool/Blackburn
UK
 
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