Connecting n pipes linux - c++

Question

I was studying about pipes recently and saw this answer:
Connecting n commands with pipes in a shell?
I was intrigued about it and tried to make like a "dynamic" one, in which I introduce a string with n process and then execute the n process (i.e ls | sort). I was trying to tokenize, save in an array, but it did not work. Here is my code of my "tokenizer":
int main()
{
char str[] = "ls | sort";
int length = (sizeof(str) / sizeof(*str))-1;
int sizeCMD = 1; //If the string has zero pipe, it means it has at least 1 process
vector<char> tempV;
for (int i = 0; i < length; i++)
{
if (str[i] == '|')
{//If the string has one |, it means it has at least 2 process.
sizeCMD++;
}
tempV.push_back(str[i]);//I was going to do something else with this, but I forgot.
//cout<<i<<" "<<tempV.at(i)<<endl;
}
int j = 0;//Current position of the cmd
string comLetter = "";//it will save every single letter in certain conditions
string comLine = "";//it will save all the characters of comLetter in certain conditions
struct command cmd[sizeCMD];
const char *ls[2];
const char *sort[2];
const char *toCChar;
for (int i = 0; i < tempV.size(); i++)
{
if (tempV.at(i) != ' ' && tempV.at(i) != '|')
{//comLetter will only save characters that are not equal to blank or |.
//cout<<tempV.at(i);
comLetter += tempV.at(i);
//cout<< comLetter <<endl;
}
if (tempV.at(i) == ' ' || i == tempV.size() - 1)
{//comLine will save everything of comLetter when it detects a blank or the very end
//cout<<comLetter<<endl;
comLine = comLetter;
comLetter = "";
}
if (tempV.at(i) == '|' || i == tempV.size() - 1)
{//cmd will save everything of comLine when it detects a | or the very end.
//cout<<j<<endl;
cout << "." << comLine << "." << endl;
//cout<<i<<endl;
//cout<<toCChar<<endl;
if(comLine == "ls"){
toCChar = comLine.c_str();
ls[0] = toCChar;
ls[1] = 0; //THIS IF
cmd[0] = {ls}; //WORKS
}
if(comLine == "sort"){
sort[0] = "sort";
sort[1] = 0; //THIS IF
cmd[1] = {sort}; //WORKS
}
/*const char *ls[2];
cout<<toCChar<<endl;
ls[0] = toCChar;
ls[1] = 0;
cout<< *ls[0] << " - "<< endl;
cmd[j] = {ls};
//cout << cmd << endl;
comLine = "";*/
j++; //The position will move by one.
}
}
return fork_pipes(sizeCMD, cmd);
}
Everything made sense to me, until I found out that const char* can't be temporal as it needs the data, so I need to create 2 const char* arrays for 2 commands. That's why I've two arrays: *sort[] and *ls[], for sort and ls.
Also, I was wondering, why these lines get "ignored":
toCChar = comLine.c_str();
ls[0] = toCChar;
I'm struggling right now, if someone could please help/guide me on how to do it, I would appreciate that.