Dump macOS kernel log

dump_kernel_log.sh

#!/bin/bash

function dumpKernelLog(){
    bt=$(sysctl -n kern.boottime | sed 's/^.*} //')

    bTm=$(echo "$bt" | awk '{print $2}')
    bTd=$(echo "$bt" | awk '{print $3}')
    bTt=$(echo "$bt" | awk '{print $4}')
    bTy=$(echo "$bt" | awk '{print $5}')

    bTm=$(awk -v "month=$bTm" 'BEGIN {months = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec"; print (index(months, month) + 3) / 4}')
    bTm=$(printf %02d $bTm)

    ep=$(/bin/date -jf '%H:%M:%S' $bTt '+%s')

    cs=$((ep - 60 ))

    bTt=$(/bin/date -r $cs '+%H:%M:%S')

    stopTime=$(log show --debug --info --start "$bTy-$bTm-$bTd $bTt" | grep loginwindow | head -1)
    stopTime="${stopTime%      *}"

    echo "Extract boot log from $bTy-$bTm-$bTd $bTt"

    log show --debug --info --start "$bTy-$bTm-$bTd $bTt" | grep -E 'kernel:|loginwindow:' | sed -n -e "/kernel: PMAP: PCID enabled/,/$stopTime/ p"
}

# Dumping kernel log
echo -e "Dumping kernel log."
dumpKernelLog &> kernel_log.txt