使用 -e 来输出转义
[leo@hadoop ~]$ echo -e '\n\t\v'
[leo@hadoop ~]$ echo '\n\t\v'
\n\t\v
[leo@hadoop ~]$ echo "hello"
hello
[leo@hadoop ~]$ echo "\"hello\""
"hello"
[leo@hadoop ~]$ echo -e '\n\t\v'
[leo@hadoop ~]$ echo '\n\t\v'
\n\t\v
[leo@hadoop ~]$ echo "hello"
hello
[leo@hadoop ~]$ echo "\"hello\""
"hello"