#!/bin/bash

# it's important to put the input_string inside single quotes
input_string='#include <stdio.h>%[\r]#define PRINT %[\s]%[\r]#define FT(...) int main(){%[\\]%[\r]'

special_cahracters=$(echo -E "$input_string" | grep -o "%\[..\]")
echo $special_cahracters

# assiocative array : https://www.gnu.org/software/bash/manual/html_node/Arrays.html
declare -A instructions
instructions["%[\r]"]=10
instructions["%[\s]"]="S"
instructions["%[\\]"]=92
instructions["%[\"]"]=34

for key