$ time ./llil3m big1.txt big2.txt big3.txt  >f.tmp
llil3m (fixed string length=6) start
get_properties     CPU  time : 2.28072 secs
vector copy        CPU  time : 0.471632 secs
vector stable sort CPU  time : 0.735042 secs
write  stdout      CPU  time : 0.67514 secs
total              CPU  time : 4.16263 secs
total             wall clock : 4 secs

real    0m4.470s
user    0m4.159s
sys     0m0.311s

$ time ./llil3m big1.txt big2.txt big3.txt  >f.tmp
llil3m (fixed string length=6) start
get_properties     CPU  time : 2.30618 secs
vector copy        CPU  time : 0.473185 secs
vector sort        CPU  time : 1.13081 secs
write  stdout      CPU  time : 0.668702 secs
total              CPU  time : 4.57897 secs
total             wall clock : 4 secs

real    0m4.889s
user    0m4.558s
sys     0m0.331s

$ time ./llil3vec big1.txt big2.txt big3.txt  >f.tmp
llil3vec (fixed string length=6) start
get_properties      CPU time : 1.46864 secs
emplace set sort    CPU time : 0.630914 secs
write stdout        CPU time : 0.847912 secs
total               CPU time : 2.9476 secs
total        wall clock time : 3 secs

real    0m3.233s
user    0m2.852s
sys     0m0.381s

$ time ./llil3grt big1.txt big2.txt big3.txt  >f.tmp
llil3grt (fixed string length=6) start
get_properties      CPU time : 2.34418 secs
emplace set sort    CPU time : 0.901415 secs
write stdout        CPU time : 0.90025 secs
total               CPU time : 4.14595 secs
total        wall clock time : 5 secs

real    0m4.784s
user    0m4.232s
sys     0m0.551s