关于汉字编码解码问题，貌似是uft-8（来自shell版）

linuxty

ack and unpack can operate in two modes, character mode (C0  mode) where the packed string is processed per character and UTF-8 mode (U0  mode) where the packed string is processed in its UTF-8-encoded Unicode form on a byte by byte basis. Character mode is the default unless the format string starts with an U . You can switch mode at any moment with an explicit C0  or U0  in the format. A mode is in effect until the next mode switch or until the end of the ()-group in which it was entered.