Tuvan

string a, b;
	int n = 3;
	a = "helloWorld";
	b.resize(n); //b.resize(1);
	b[0] = a[n];

string a, b;
a = "helloWorld";
b+=a[3];

#include <iostream>                                   // для оператора cout
#include <cstdio>                                     // для функции rename
#include <sys/stat.h>
#include <fstream>
using namespace std; 
int main()
{   
    mkdir ("/var/www/hls/live.m3u8", 0775);
    ifstream infile;
    ofstream outfile;
 
    infile.open("/var/www/hls/55/live.m3u8");
    outfile.open("/var/www/hls/live.m3u8");
 
    char buffer[1000];        
    int c=0; 
    while(!infile.eof())       
    {
       if(c>=4){
        infile.getline(buffer,sizeof(buffer));         
        outfile<<buffer<<endl;    }
        else c++;
    }
 
    infile.close();         
    outfile.close();    
    return 0;
}