Shell Programming and Scripting

ENV varibles set using a script are not retailed once the script execution is done. But if the same ENV variable is set in command line, it is retained.

Consider the below case

Code:

$ cat ti
export MDS_CODE_HOME=`pwd`
echo $MDS_CODE_HOME
rsamadde@pcasvs04 ~/R2ANew
$ ti
/export/home/rsamadde/R2ANew <- MDS_CODE_HOME is set here
rsamadde@pcasvs04 ~/R2ANew
$ echo $MDS_CODE_HOME
<- MDS_CODE_HOME not retaimed here
rsamadde@pcasvs04 ~/R2ANew
$ export MDS_CODE_HOME=`pwd` <- MDS_CODE_HOME is set here
rsamadde@pcasvs04 ~/R2ANew
$ echo $MDS_CODE_HOME
/export/home/rsamadde/R2ANew <-MDS_CODE_HOME is retaimed here
rsamadde@pcasvs04 ~/R2ANew
$

I am using SSH Client from in WIndows XP to login. The issue is with all users logging in from my machine. So this might be a SSH issue.

Environment variables cannot travel "up stream" to the calling process.

When a programme is invoked, the current process' environment (exported variables in terms of the shell) is copied and becomes a part of the child process' allocated memory. Any changes to the environment by that process are made to its own copy which is deleted when the process terminates.

Logistically this is a good thing. If a script invokes a command, it would be chaos if the command changed the parent's environment variables.

Nothing to do with SSH this is standard shell functionality as agama points out.

You need to execute your script in the current shell. Execute it like this:

Code:

$ . ti

Thanks for the quick reply. In our project, it is configured in such a way that once you login and execute a script, it sets the ENV variables for that session and retains during the entire life. And this is working fine for all other users when they are loggin in from their PC's. But the same user when logging in from my PC, it is not working.

---------- Post updated at 09:59 PM ---------- Previous update was at 09:55 PM ----------

@Chubler_XL :
Executing it in local shell as "$ . ti" does not help Please note this is not the actual script but the same script is working when logged in from different PC's. The problem is with the PC am using. And hence the thought of SSH Shell.

---------- Post updated at 10:04 PM ---------- Previous update was at 09:59 PM ----------

The issue is resolved