#!/usr/bin/env sh

# estimate sytem boot time

# [debug] enable execution tracing
#set -x
set -e

# raw input data
#date +%s
#sysctl_t0_str=$( sysctl kern.boottime | mawk -F= '{print($NF)}' )
#sysctl_t0=$( date -jf "%a %b %d %H:%M:%S %G" "${sysctl_t0_str}" +%s )


# check for saved state
if [ -f t0_est.log ] ; then {
    t0_est="$( cat t0_est.log )"
} else {
    t0_est=""
} fi

printf "n t_est t_unc t_up_est t_up_unc t0_est t0_unc\n" | column -t
for N in $(seq 0 10080) ; do

    printf "${N} ${t0_est}\n" | column -t
    t0_est=$( mawk -f ckt0.awk ${t0_est} | tail -n2 )
    #mawk -f ckt0.awk
    sleep $( mawk 'BEGIN {print(sqrt( rand()^2.0 + 1.0 ))}' )
    #sleep $( echo $t0_est | mawk '{print(sqrt( ((60.0*$4)/(60.0 + $4))^2.0 + rand()^2.0 ))}' )
    #sleep $( echo $t0_est | mawk '{print(sqrt( ($2)^2.0 + ($4)^2.0 + ($6)^2.0 + rand()^2.0 ))}' )
    #sleep $( echo $t0_est | mawk '{print( 10.0 - (systime() - $5)%10.0 + 0.5*rand()^2.0 )}' )

done

printf "${t0_est}\n" | tee t0_est.log

# [debug] disable execution tracing
set +x