Did you know you could work with strings in calc? For an example, let’s find out what “Hello world” is in binary:
M-x calc d 2 (change the to binary mode) "Hello world (Enter the string "Hello world" which turns into a vector of numbers) Result: 1: [2#1001000, 2#1100101, 2#1101100, 2#1101100, 2#1101111, 2#100000, 2#1110111, 2#1101111, 2#1110010, 2#1101100, 2#1100100]
And similarly, we can convert back. If someone gave you the binary number:
01001000011011110110110001100001 and asked what the string was, I’d have no
idea… but calc knows:
d " (changes to string mode) C-x b scratch (whaaa, leave calc?) 01001000011011110110110001100001 (enter the number we're parsing) C-a (go to the start of the line) C-x ( (start a macro) 2# (prefix the number with a binary indicator) C-u 8 C-f (Jump forward 8 characters) <space> (insert a space to separate the numbers) C-x ) (end the macro) C-x e (repeat the macro) e e (repeat twice twice more) C-<space> (set mark) C-a (goto beginning of line) C-x <asterisk> g (copy region into calc) Result: 1: "Hola"
And there you have it! Maybe there is an easier way to convert from the giant binary number to a vector of bytes, but I don’t know it yet.