1. xrfang@desktop:~$ cat test.txt
  2. abcdefg,test
  3. abcdefg,~1111
  4. abcdefg,~2222
  5. xrfang@desktop:~$ cat test.txt|sort
  6. abcdefg,~1111
  7. abcdefg,~2222
  8. abcdefg,test
  9. xrfang@desktop:~$