How to detect screenshot status

[XDID]

When I try to use zbarimg to decode a QR code, I notice that if I press Esc to cancel during the screenshot interface, the script keeps running in the background.

I’ve tried using niri msg action screenshot || exit 1, but it seems that when I cancel the screenshot with Esc, niri still returns exit code 0.

How can I terminate the script when the screenshot is canceled?
Here is my code

#!/usr/bin/sh
# qrdecode: decode screenshot qrcode
niri msg action screenshot &
(niri msg event-stream | grep -m 1 --line-buffered "Screenshot captured" > /dev/null)
wl-paste | zbarimg --raw - | tr -d '\n' | wl-copy

[XDID]

#!/usr/bin/sh

# qrdecode: decode screenshot qrcode
niri msg action screenshot &
event=$(timeout 10 niri msg event-stream | grep -m 1 "Screenshot captured")
if [[ -n "$event" ]]; then
  wl-paste | zbarimg --raw - | tr -d '\r\n' | wl-copy
else
  exit 1
fi

This way works great for me