strace-log-merge

#!/bin/sh

if test $# = 0; then
	cat >&2 <<__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__
	exit 1
fi

logfile=$1
pfxlen=${#1}

for file in "$logfile".*; do
	[ -f "$file" ] || continue
	suffix=${file:1+$pfxlen}
	[ "$suffix" -gt 0 ] 2> /dev/null || {
		echo "Skipped file '$file' (bad suffix)" >&2
		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 "s/^/$pid /" < "$file"
	echo
done \
| grep -v '^$' | sort -k2