Changing PATH variable...

imprise · 05-20-2009, 10:07 AM

Hi all;

Suppose I have created /etc/opt/mydb directory to store my applications executable and I want to add this path to my PATH environment variable. Right?

For this reason, I execute the following command:

PATH=$PATH:/var/opt/mydb

and everything works fine. But when I open a new shell prompt and the issue the echo $PATH command, the new variable does not show?

How can I solve this problem?

Thanks

nuwen52 · 05-20-2009, 10:39 AM

The fix depends on what shell you are running. You have to add your path change into the shell startup file. For bash, it would be .bashrc in your home directory. For ksh it would be the .kshrc file.

If you don't have one in your home directory, you are probably using a system default one. For bash, that would be, /etc/bashrc file. You probably shouldn't modify that one, but copying it into your directory as a .bashrc may work, and you can modify that one.

imprise · 05-20-2009, 11:07 AM

Quote:

Originally Posted by nuwen52

The fix depends on what shell you are running. You have to add your path change into the shell startup file. For bash, it would be .bashrc in your home directory. For ksh it would be the .kshrc file.

If you don't have one in your home directory, you are probably using a system default one. For bash, that would be, /etc/bashrc file. You probably shouldn't modify that one, but copying it into your directory as a .bashrc may work, and you can modify that one.

Thanks for your reply. I know that I must include it to my bash configuration files. But I read on a book that when I execute the "export variable" command, before I reboot the system, I can use the variable in any other shells that I open afterward. But the command does not work...

kirukan · 05-20-2009, 11:24 AM

Add this PATH & export PATH in to your /etc/profile file

nuwen52 · 05-20-2009, 11:51 AM

If I am misunderstanding what you said, just ignore this.

I could be wrong, but I don't think any changes you make to PATH would carry over past a reboot unless you add something to either the profile or rc file for that shell. And, I think that goes for any variables you define in a shell, whether you export or not. Now, if you change the value of a variable, then spawn an new shell from the one you modified it in, that variable is available.

Example.
# PATH2=newpath;export PATH2
# /bin/ksh
$ echo $PATH2
newpath

colucix · 05-20-2009, 12:09 PM

Quote:

Originally Posted by imprise

Thanks for your reply. I know that I must include it to my bash configuration files. But I read on a book that when I execute the "export variable" command, before I reboot the system, I can use the variable in any other shells that I open afterward. But the command does not work...

That's not quite correct. When you export a variable it will be inherited from child processes, that is from every subshell which is child of the current shell. But if you open another session (terminal) you start another parent shell which does not know anything about the changes made in the first.

In summary, every open terminal on your desktop has its own environment as set up by the initialization files (/etc/bashrc, /etc/profile, ~/.bash_profile, ~/.bashrc and so on). Any local change is ignored from the other shells.