URL2File

readme.md

Overview

The URL2File is a small utility which returns a std::ifstream from an URL

Internally it relies simply on wget to download the file locally into a file with a certain temporary name

main.cpp

#include <stdio.h>
#include <string>
#include <iostream>
#include <fstream>
#include <memory>

#include "URL2File.hpp"

using namespace std; 

int main(int argc, char** argv)
{
    const string url = "https://httpbin.org/get"; 
    string res; 
    
    auto temp = URL2File(url)(); 
    while(!temp->eof())
    {
        string t_res; 
        *temp >> t_res;
        res += t_res; 
    }
    
    std::cout << "Completed " << std::endl; 
    std::cout << "Result = " << res << std::endl; 
    
}

URL2File.hpp

#include <stdio.h>
#include <fstream>
#include <stdexcept>
#include <memory>

class URL2File
{
    public: 
    URL2File( const std::string& _url ) : url(_url), temp_fn("/tmp/temp.txt"), file(nullptr) {}
    ~URL2File() { pclose(file); }
    
    std::shared_ptr<std::ifstream> operator()() 
    {
        file = popen(("wget "+url+" -O " + temp_fn).c_str(),"r");
        if(!file) throw std::runtime_error("Error while retrieving from url = " + url); 
        return std::shared_ptr<std::ifstream>(new std::ifstream(temp_fn)); 
        
        //std::ifstream temp(temp_fn); 
        //return temp; 

    }
    
    const std::string url; 
    
    private: 
    std::string temp_fn; 
    FILE* file; 
};