#! /bin/sh

# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# This script prints the last part of a syslog-timestamped file to the
# stdout.  By default the content of /var/log/messages is printed. Options:
# --bytes N        cap collected data at N bytes (default 512K)
#
# Note option order is important (TODO(sleffler) rewrite w/ shflags)

if [ "$1" = "--bytes" -o "$1" = "-c" ]; then
  MAXDATA="$2"; shift; shift
else
  MAXDATA='512K'
fi
LOGFILE=${1:-/var/log/messages}

# create list of files assuming normal log rotation

LOGFILES="${LOGFILE}"
BASENAME="${LOGFILE%%.*}"
EXTENSION="${LOGFILE#*.}"
if [ "${BASENAME}" = "${EXTENSION}" ]; then
  EXTENSION=""
else
  EXTENSION=".${EXTENSION}"
fi
for i in 1 2 3 4 5 6 7 8 9; do
  FILE="${BASENAME}".$i${EXTENSION}
  [ -f "${FILE}" ] || break
  LOGFILES="${FILE} ${LOGFILES}"
done

cat ${LOGFILES} | tail -c ${MAXDATA}