#!/bin/sh
#
# This script processes strace -ff -tt output.  It merges the contents of all
# STRACE_LOG.PID files and sorts them, printing result on the standard output.
#
# Copyright (c) 2012-2018 The strace developers.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

show_usage()
{
	cat <<__EOF__
Usage: ${0##*/} STRACE_LOG

Finds all STRACE_LOG.PID files, adds PID prefix to every line,
then combines and sorts them, and prints result to standard output.

It is assumed that STRACE_LOGs were produced by strace with -tt[t]
option which prints timestamps (otherwise sorting won't do any good).
__EOF__
}

dd='\([0-9][0-9]\)'
ds='\([0-9][0-9]*\)'

if [ $# -ne 1 ]; then
	show_usage >&2
	exit 1
elif [ "$1" = '--help' ]; then
	show_usage
	exit 0
fi

logfile=$1

for file in "$logfile".*; do
	[ -f "$file" ] || continue
	suffix=${file#"$logfile".}
	[ "$suffix" -gt 0 ] 2> /dev/null ||
		continue
	pid=$(printf "%-5s" $suffix)
	# Some strace logs have last line which is not '\n' terminated,
	# so add extra newline to every file.
	# grep -v '^$' removes empty lines which may result.
	sed -n "s/^\($dd:\)\?\($dd:\)\?\($ds\.\)\?$ds /\2\4\6\7 $pid \0/p" < "$file"
	echo
done \
| sort -s -n -k1,1 | sed -n 's/^[0-9][0-9]* //p'

rc=$?
[ $rc -eq 1 ] &&
	echo >&2 "${0##*/}: $logfile: strace output not found"
exit $rc