如何struck.pack（）在创建包

Question

我遇到一个程序这一行使用Python创建的ICMP PING包使用

header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, my_checksum, ID, 1) 

什么是“bbHHh”是指这里

Answer 1

的文档是在这里：https://docs.python.org/2/library/struct.html - 这是一个格式字符串。你的具体的例子是指在C相当于：

struct Foo { 
    signed char a; 
    signed char b; 
    unsigned short c; 
    unsigned short d; 
    short e; 
} 

Answer 2

入住这里： https://docs.python.org/2/library/struct.html#format-characters

这意味着

ICMP_ECHO_REQUEST is a signed char -> integer in python 
0 the same 
my_checksum is unsigned short -> integer in python 
ID the same 
h is a short -> integer in python