Read message up to % character - c++

Question

I have a char array:
char arr[] = "%RED**dsa0x0%xcа%wq233SSS%(dsa........";
The array must be read from the % sign to the next %. That is, the message begins with % and has an unknown length (there can be no % in the middle of the message).
Here is the code:
void SaveMessToVec(const string& str)
{
tail = tail + str;
if (tail.empty()) return;
assert(tail[0] == 0x24);
while (true)
{
size_t f = tail.find(0x24, 1);
if (f == string::npos) return;
string message = tail.substr(0, f);
//cout << message << '\n';
vecForAP.push_back(message);
tail.erase(0, f);
}
}
However, my controller can't work with string and vector. How to rewrite this code to use only char?

Answer 1

If you can use vector and string you can use this function.
std::vector<std::string> split(const std::string& s, char delimiter) {
std::vector<std::string> tokens;
std::string token;
std::istringstream tokenStream(s);
while (std::getline(tokenStream, token, delimiter)) {
if(token.size()!=0)
tokens.push_back(token);
}
return tokens;
}
int main() {
std::string str = "%RED**dsa0x0%xcа%wq233SSS%(dsa";
std::vector<std::string> vec = split(str,'%');
for(auto &v : vec)
std::cout << v << std::endl;
return 0;
}
If you cannot use string and vector you can use strtok(). strtok can tokenize a char array
int main() {
char arr[] = "%RED**dsa0x0%xcа%wq233SSS%(dsa";
char* token = strtok(arr,"%");
while(token != NULL) {
std::cout << token << std::endl;
token = strtok(NULL,"%");
}
return 0;
}
How you tried to do this is not the appropiate way to tokenize a string. But if you want to do this way I show you a solution for you.
I do not understand your whole code procisely but maybe this would be good enough for you.
vector<string> vecForAP; // global variable to store data for you
void SaveMessToVec(string& str) {
str.erase(str.begin()); //because the first letter is %
while (true){
size_t f = str.find('%');
if (f == string::npos) {
vecForAP.push_back(str);
return;
}
string message = str.substr(0,f);
vecForAP.push_back(message);
str.erase(0, f+1);
}
}