Baffled by quotes

[Larry]

I have a machine that I use to pass program updates between three people.
I am trying to get a notification when someone is using scp to get the latest version.
I keep getting unmatched quote errors.
So far, I am simply trying to get one rsh line sent, which works fine, but now I am trying to get a notification.
IP address & port number has been sanitized. Variable 'out' contains "randy - name of program and revision"

#!/usr/bin/rexx

address system "rsh larry@123.456.789.10 -p4546 'ps aux | grep randy | grep scp'" with output stem randy.

out = word(randy.1,1) || " - " || substr(randy.1,84)

say out

sendstring = 'address system "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u larry)/bus /usr/bin/notify-send -t 0 """ || out || "'"

say sendstring

interpret sendstring

Here's what I want the sendstring to say:

[Mike Protts]

I can see a mismatch of quotes in the sendstring = line, the first single quote is not being matched with the last as that's in double quotes. The number of double quotes around the notify-send payload will then not match, so will need fixing.

I'm not sure why the interpret statement is needed here, it's very powerful when needed, but also totally opaque, so a comment explaining what it's expected to look like when run is essential. Usually when writing the comment the way to avoid interpret jumps out in better logic.

[Larry]

Sorry, I edited my post to add "Here's what I want the sendstring to say:" but then I neglected to add the example.

DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u larry)/bus /usr/bin/notify-send -t 0 "randy - Test 3.14"

I think my problem is that I don't know enough about 'address system' .
I have 'The Regina Rexx Interpreter Version 3.3', and the examples all seem to say that I need to quote the entire string.

However, I did just figure out that I can use a variable to hold the string, which would not require an 'interpret'.

So I did figure it out, but not until I read your response, which gave me a few clues.
Thanks very much.

Here's how I did it. I have a lot more to go into it, but the rest should be easy.

#!/usr/bin/rexx

address system "rsh larry@123.456.789.10 -p4242 'ps aux | grep randy | grep scp'" with output stem randy.

out = '"' || word(randy.1,1) || " - " || substr(randy.1,84)|| '"'

sendstring = 'DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u larry)/bus /usr/bin/notify-send -t 0 '

sendstring = sendstring || out

say sendstring

address system sendstring