daemon: change get_ident()

The new method still uses the start time of the process, but figures and
formats it differently.  The new way takes the time in "jiffies" since the
system booted, using `/proc/$pid/stat`.  The old way used `lstart` from
`ps`, which calculated the time by adding that to the boot time.  This can
drift though, as NTP adjusts the system time.  I was frequently seeing one
second discrepancies, causing duplicate processes to spawn.

1 files changed, 2 insertions, 2 deletions

diff --git a/daemon.sh b/daemon.sh
index 3fcbc99..4197fc8 100644
--- a/daemon.sh
+++ b/daemon.sh
@@ -2,7 +2,7 @@
 
 get_ident() {
 	local pid=$1
-	ps h -o lstart -p "$pid"
+	cut -d ' ' -f 22 /proc/$pid/stat
 }
 
 is_running() {
@@ -44,7 +44,7 @@ main() {
 		echo "daemon: starting \`$id'"
 		nohup "$@" > "$OUTFILE" 2> "$ERRFILE" &
 		pid=$!
-		echo "$pid" "`get_ident $pid`" > "$PIDFILE"
+		echo "$pid" "$(get_ident $pid)" > "$PIDFILE"
 	fi
 }