Interpreting the time in dmesg data

pwabrahams · 02-07-2014, 07:57 AM

The dmesg log has lines like this:

[97082.333768] ehci-pci 0000:00:1d.0: setting latency timer to 64

How can I determine the clock time when this message was issued?

colucix · 02-07-2014, 08:37 AM

The timestamp in dmesg is in number of seconds.nanoseconds from the system start-up, therefore you should retrieve the start-up time (as returned by the uptime command or from /proc/uptime) and do some calculations. Here is a little awk program to do the trick:

Code:

BEGIN {
  "cat /proc/uptime" | getline result
  split(result,uptime)
  start = systime() - int(uptime[1])
}

$1 ~ /\[[0-9.]+\]/ {
  gsub(/\[|\]/,"",$1)
  $1 = ("[" strftime("%c",start+int($1)) "]")
}

1

or in a single (long) command line:

Code:

dmesg | awk 'BEGIN {"cat /proc/uptime" | getline result; split(result,uptime); start = systime() - int(uptime[1])} $1 ~ /\[[0-9.]+\]/ {gsub(/\[|\]/,"",$1); $1 = ("[" strftime("%c",start+int($1)) "]")}1'