#!/bin/sh
# File: /usr/local/bin/kvm-user-daemon.sh
# Location: vm2
# Author: bgstack15
# Startdate: 2023-01-11-4 11:37
# Title: KVM user daemon
# Project: kvm-mapping
# Purpose: daemon that runs inside user session and runs a script when specific USB device is plugged in
# History:
# Usage:
#    Run at start of session, such as in ~/.fluxbox/startup
# Reference:
#    original design (at least my third time) of stdout/stderr timestamps and logging
# Improve:
# Dependencies:
# Documentation:
test -z "${LOGFILE}" && test -d ~/log && LOGFILE=~/log/kvm
test -z "${LOGFILE}" && test -d ~/.log && LOGFILE=~/.log/kvm
test -z "${LOGFILE}" && export LOGFILE=/tmp/kvm-log
KVMFILE=/run/kvm/kvmfile
STOPFILE=/tmp/stop-kvm # touch this file to stop the daemons for all users
# The user should set RUNSCRIPT, which is what should happen when the kvm is switched to this output.
test -z "${RUNSCRIPT}" && RUNSCRIPT=~/bin/kvm-plugged-in.sh
! test -x "${RUNSCRIPT}" && RUNSCRIPT=/usr/local/bin/kvm-plugged-in.sh
# Crazy nesting allows stdout, stderr prepended with timestamps and "STDERR", both to normal streams and to the logfile.
{
   {
      {
         # Safety valve. When this file exists, the loop stops.
         while ! test -f "${STOPFILE}" ;
         do
            sleep 1
            test -f "${KVMFILE}" && {
               #env
               #echo "sample error" 1>&2
               echo "kvm input detected, running \"${RUNSCRIPT}\""
               "${RUNSCRIPT}"
               # delay a few seconds, because switching inputs fastis unlikely and not recommended, and so that any other user daemons looking for it can find it and also react.
               { sleep 3 ; rm -f "${KVMFILE}" ; }
            }
         done
      } 2>&3 1>&4
   } 3>&1 1>&4 | plecho "STDERR:" | tee -a "${LOGFILE}" 1>&2 
} 4>&1 | plecho | tee -a "${LOGFILE}"
# Delay a few seconds so other daemons can also find it and stop
sleep 3 ; rm "${STOPFILE}" 1>/dev/null 2>&1
# exit 0 with this nop
: