Small script to get the display started by XRDP. This is useful when you want to launch GUI apps from SSH on the XRDP session.

get_xrdp_display.sh

#!/bin/bash

# find session ids for current user
SESSION_IDS=$(loginctl list-sessions -o json | jq -r '.[] | select(.user == "'"$USER"'") | .session')

# find XRDP sessions
XRDP_SESSION_IDS=()
for item in $SESSION_IDS; do
  SERVICE=$(loginctl show-session -P Service "${item}")
  if [[ $SERVICE == "xrdp-sesman" ]]; then
    XRDP_SESSION_IDS+=("${item}")
  fi
done

# find active XRDP sessions
ACTIVE_XRDP_SESSION_IDS=()
for item in "${XRDP_SESSION_IDS[@]}"; do
  STATE=$(loginctl show-session -P Active "${item}")
  if [[ $STATE == "yes" ]]; then
    ACTIVE_XRDP_SESSION_IDS+=("${item}")
  fi
done

# if there is no active XRDP session, exit
if [[ ${#ACTIVE_XRDP_SESSION_IDS[@]} -eq 0 ]]; then
  echo "ERROR: No active XRDP session found." >&2
  exit 1
fi

# if there are multiple active XRDP sessions, exit
if [[ ${#ACTIVE_XRDP_SESSION_IDS[@]} -gt 1 ]]; then
  echo "ERROR: Multiple active XRDP sessions found." >&2
  exit 1
fi

# get the active XRDP session id
ACTIVE_XRDP_SESSION_ID="${ACTIVE_XRDP_SESSION_IDS[0]}"
echo "INFO: Active XRDP session id: ${ACTIVE_XRDP_SESSION_ID}" >&2

# print export command to eval
DISPLAY=$(loginctl show-session -P Display "${ACTIVE_XRDP_SESSION_ID}")
echo "export DISPLAY=${DISPLAY}"