find date of last boot

[Chris Hill]

On Thu, 7 Jun 2012, Fbsd8 wrote:

> dmesg command does not show date of last boot.
>
> Are there some other commands to find date of last boot?

That was fun. Google helped me with this; the crappy skillz are all 
mine.

  --- cut here ---
#!/bin/sh
#
# Find date of last boot
#
DAYS_UP=`uptime | awk '{print $3}'`
SEC_UP=`echo "${DAYS_UP} * 86400" | bc`
DATE=`date`
EPOCH_DATE=`date -j -f "%a %b %d %T %Z %Y" "${DATE}" "+%s"`
BOOT_SEC=`echo "${EPOCH_DATE} - ${SEC_UP}" | bc`
BOOT_DATE=`gawk -v duh=${BOOT_SEC} 'BEGIN{print strftime("%Y-%m-%d",duh)}'`
echo "Last boot on ${BOOT_DATE}"
  --- cut here ---

Example from this machine:
$ ./boot_date.sh
Last boot on 2010-12-26
$

Enjoy.

-- 
Chris Hill               chris at monochrome.org
**                     [ Busy Expunging </> ]