AIX

Can you please let me know which variable has precedence . The variable in /etc/environment or the resource file ENV. As /etc/environment file is sourced for every process and ENV is sourced for login shells and sub shell's. i should see the value from /etc/environment file in my command(running as process). However i see the value of ENV though im not starting any sub shell.

Are varaibles in ENV used only by korn shell?

It is a bit like the chicken and the egg. ENV is in the environment. When you log in or arrive in a terminal-less world due to cron, at, remsh, rexec, rsh, ssh, ssh2, xterm -ls, etc., you inherit some environment, and it may be set up from /etc/environment first, and other places later, and shells have their own preferred ways to enhance the environment either when invoked (.kshrc) or just at login (.profile). So, you have to start with root init and work forward through the daemons that get your session going. It's not a single environment source, generally, but the sum of many modifications. See man execve about starting a process with one specific environment.