...
>         If I want to search for a particular
>         pattern, I would try
>
>                 cat.hpbin.sys FOO | grep "foo test"
>
>         however, it doesn't recognize "|" as the pipe. how is that
>         being represented in MPE?

The above command is easier to use from the POSIX shell.
In the CI enter:
    SH   (if you have the SH UDC cataloged)

If this does not work, enter:
    sh.hpbin.sys -L

This gets you in the POSIX shell.
Now try:
    cat FOO |grep "foo test"

Or more simply:
    grep pattern file(s)

Man pages are available in the shell.

Jeff Vance, CSY