root@test:/srv/ppk-log/yz-ppk-admin/test# touch {1,2,3} {a,b,c}.txt
root@test:/srv/ppk-log/yz-ppk-admin/test# l
1  2  3  a.txt  b.txt  c.txt
root@test:/srv/ppk-log/yz-ppk-admin/test# touch {5..8}
root@test:/srv/ppk-log/yz-ppk-admin/test# l
1  2  3  5  6  7  8  a.txt  b.txt  c.txt

root@test:/srv/ppk-log/yz-ppk-admin/test# touch {10..12}.txt
root@test:/srv/ppk-log/yz-ppk-admin/test# l
1  10.txt  11.txt  12.txt  2  3  5  6  7  8  a.txt  b.txt  c.txt