14/09/13 14:41:53.02 .net
>>9
bash-3.2$ sw_vers
ProductName: Mac OS X
ProductVersion: 10.9.4
BuildVersion: 13E28
bash-3.2$ echo $LANG
ja_JP.UTF-8
bash-3.2$ sort --version | head -n1
sort (GNU coreutils) 5.93
bash-3.2$ cat a.txt
a1
A2
_1
bash-3.2$ sort a.txt
A2
_1
a1
bash-3.2$ sort -d a.txt
_1
A2
a1
bash-3.2$ sort -df a.txt
_1
a1
A2