什么是PHP打包和解包功能的实时使用？

Question

I saw some file generation codes which uses the pack function.

echo pack("ssssss", 0x809, 0x8, 0x0, 0x10, 0x0, 0x0);

What this is doing exactly?

s signed short (always 16 bit, machine byte order)

I dont know why i am not able to understand this in realtime. Am not asking a theoretical answer

When i execute the php , file got generated with some stange characters which is not identified by ms excel.

I just want to know the use of pack(), where to use and how to use?

Answer 1

pack is generally used to generate raw binary data. For example, I saw it used to generate zip files before native functions/classes were available in PHP for that.