#!/usr/bin/env zsh

PANEL_FIFO="$1"
PREFIX="$2"
DELAY="$3"
CMD="$4"

exec 5>"$PANEL_FIFO"

main() {
    REPLY="$($SHELL -c "$CMD")"
}

while :; do
    main
    echo "$PREFIX $REPLY" >&5
    sleep "$DELAY"
done