如何struck.pack（）在創建包

Question

我遇到一個程序這一行使用Python創建的ICMP PING包使用

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

什麼是「bbHHh」是指這裏

Answer 1

的文檔是在這裏：https://docs.python.org/2/library/struct.html - 這是一個格式字符串。你的具體的例子是指在C相當於：

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

Answer 2

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

這意味着

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