bootstat/bootstat_archive

#!/bin/sh
# Copyright 2012 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

if [ $# -ne 1 ]; then
  echo "usage: $(basename "$0") <archive-dir>" >&2
  exit 1
fi

ARCHIVE="${1%/}"
mkdir -p "${ARCHIVE}"

# Change the working directory since relative paths (without directories) allow
# us to check for parent symlinks once without introducing a time-of-check
# time-of-use race.
if ! cd "${ARCHIVE}" || [ "$(readlink -f .)" != "${ARCHIVE}" ]; then
  echo "bootstat_archive requires a non-symlinked archive-dir" >&2
  exit 1
fi

# All uptime values are recorded as "time since boot".  To
# facilitate comparing archived times against other times measured
# against a different boot time, we capture timestamps with both
# `date` and `bootstat` so we can reconstruct times in UTC later.
# Since the two gathered times will be slightly different, we run
# `date` at both the start and end of the operation, so as to put a
# bound on the measurement error.

date '+%s.%N' >'./timestamp'
bootstat archive
# -Pp: don't follow source symlinks; preserve mode, owner and file times.
cp --remove-destination -Pp /run/bootstat/uptime-* /run/bootstat/disk-* \
  /run/bootstat/sync-rtc-* /proc/sys/kernel/random/boot_id \
  .
date '+%s.%N' >>'./timestamp'