Is it possible to get the start time of an old running process? It seems that ps
will report the date (not the time) if it wasn\'t started today, and only the y
As a follow-up to Adam Matan's answer, the /proc/
directory's time stamp as such is not necessarily directly useful, but you can use
awk -v RS=')' 'END{print $20}' /proc/12345/stat
to get the start time in clock ticks since system boot.1
This is a slightly tricky unit to use; see also convert jiffies to seconds for details.
awk -v ticks="$(getconf CLK_TCK)" 'NR==1 { now=$1; next }
END { printf "%9.0f\n", now - ($20/ticks) }' /proc/uptime RS=')' /proc/12345/stat
This should give you seconds, which you can pass to strftime()
to get a (human-readable, or otherwise) timestamp.
awk -v ticks="$(getconf CLK_TCK)" 'NR==1 { now=$1; next }
END { print strftime("%c", systime() - (now-($20/ticks))) }' /proc/uptime RS=')' /proc/12345/stat
Updated with some fixes from Stephane Chazelas in the comments; thanks as always!
If you only have Mawk, maybe try
awk -v ticks="$(getconf CLK_TCK)" -v epoch="$(date +%s)" '
NR==1 { now=$1; next }
END { printf "%9.0f\n", epoch - (now-($20/ticks)) }' /proc/uptime RS=')' /proc/12345/stat |
xargs -i date -d @{}
1 man proc; search for starttime.