源文件为：
[root@luo5 wangxx]# cat -v luo.txt
J Luo
Soutth jfsa
Nanjing,china
Y Zhang
Victory University
Nejflja,Australia
D Hou
Beijing University
Melhouse,china
实现排序
[root@luo5 wangxx]# cat luo.txt |awk -v RS="" '{gsub("\n","@");print}' | sort | awk -v OFS="\n\n" '{gsub("@","\n");print}'
D Hou
Beijing University
Melhouse,china
J Luo
Soutth jfsa
Nanjing,china
Y Zhang
Victory University
Nejflja,Australia