Laurent Bercot:
for logdir in `cat logdir_list` ; do (cd $logdir && cat *.s *.u current) ; done | sort > logfile
find `cat logdir_list` -maxdepth 1 -type f \( -name '*.[su]' -o -name current \) -print0|xargs -0 sort -m -- > logfile
sort can do a merge sort directly from the original files, which are of course already sorted. It's better when one's logs are *big*.
