C中二进制文件的解码器

Question

I need to decode text from binary files and compare it with text(which is written by user) in my program and also I need to decode text to binary text. Example:

1. 011011000110111101101100 => sometext
2. sometext => 011011000110111101101100

It should be 2 functions. How can I do it?

Answer 1

I understand, so here's how it works :

• You need a function can convert 8 bits binary's numbers (can add '0' after the numbers to always have 8bits), every numbers you get can be converted with ASCII table, for exemple l is 108, I assume you already know
• an other function can convert ASCII characters to 8bits binary's numbers

Binary to Decimal :

01101100 -> 0.2^0 + 0.2^1 + 1.2^2 + 1.2^3 + 0.2^4 + 1.2^5 + 1.2^6 + 0.2^7

it's very easy

Decimal to Binary : Get the rest and the quotient :

108/2 : q = 54 r = 0
54/2  : q = 27 r = 0
27/2  : q = 13 r = 1
13/2  : q = 6  r = 1
6/2   : q = 3  r = 0
3/2   : q = 1  r = 1

take the last quotient and all rest : 1101100, add a 0 to have 8 bits : 01101100