原因：

the expression '\t' to indicate a tab character (0x09) in the scripts.
However, most versions of sed do not recognize the '\t' abbreviation,
so when typing these scripts from the command line, you should press
the TAB key instead. '\t' is supported as a regular expression
metacharacter in awk, perl, and HHsed, sedmod, and GNU sed v3.02.80."

解决方案 ：

使用 <ctrl-v> 然后是 TAB 键，它会出现一些空白，那就是制表符。