#/bin/sh

# This script monitors if a dvb device's frontend is opened by VDR.
# Can be used with a single tuner or with two tuners.
# Output:
#  1  - adapter 0 is on
#  2  - adapter 1 is on
#  3  - both are on
#  -  - both are off
#  .  - VDR is not running

# VDR executable. Change to vdr.bin for OpenELEC.
VDR=vdr

# Uncomment this if you want to output timestamps of status changes
PRINT_TIMESTAMPS=yes

old_status='*'
old_stamp=$(date +%s)
while true; do
    vdrpid=$(pidof $VDR)
    if [ -z "$vdrpid" ]; then
        status='.'
    else
        mask=0
        for adapter in 0 1; do
            if lsof -p $vdrpid 2>/dev/null | grep -q "adapter$adapter/frontend"; then
                mask=$(($mask + $adapter + 1))
            fi
        done
        if [ $mask -eq 0 ]; then
            status='-'
        else
            status=$mask
        fi
    fi
    stamp=$(date +%s)
    if [ -n "$PRINT_TIMESTAMPS" -a "$old_status" != "$status" ]; then
        printf '\n[%s]  %s>%s  +%ds\n' $(date +%H:%M:%S) "$old_status" $status $(($stamp - $old_stamp))
        old_stamp=$stamp
    fi
    old_status=$status
    printf "$status"
    sleep 1
done