There is an additional, system-wide, customization file known as
/etc/profile. If this file exists, the Korn shell
reads and executes it as the very first thing it does, even before
reading your personal .profile file.
This is where your system administrator places commands that should be
executed by every user upon login, and where
he or she places system-wide defaults, such as adding extra directories
to the PATH variable
(which, as you will see later in this chapter, tells the shell where to
look for programs to run).
It pays to be aware of this file, since it may have settings in it that
you might wish to override in your own .profile file.
(At least, once you understand what it's doing!)
If the file exists, it will be readable and will contain shell commands in it,
just like your .profile. It may be worthwhile to peruse the version
on your system; you may learn something that way.