code: final

main.cpp

@@ -1,3 +1,6 @@
+#include <sstream>
+#include <string>
+#include <curl/curl.h>
 #include <iostream>
 #include <vector>
 #include <string>
@@ -29,9 +32,39 @@ Input input_data(istream& in, bool prompt = 0) {
     return input;
 }
 
-int main () {
-    auto in = input_data(cin);
-    auto bins = make_histogram(in.numbers, in.bin_count);
+size_t write_data(void* items, size_t item_size, size_t item_count, void* ctx) {
+    auto data_size = item_size * item_count;
+    stringstream* buffer = reinterpret_cast<stringstream*>(ctx);
+    buffer->write(reinterpret_cast<const char*>(items), data_size);
+    return 0;
+}
+
+Input download (const string& address) {
+    stringstream buffer;
+    CURL *curl = curl_easy_init();
+    if(curl) {
+        CURLcode res;
+        curl_easy_setopt(curl, CURLOPT_URL, address.c_str());
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &buffer);
+        res = curl_easy_perform(curl);
+        if(res != false) {
+            cout << curl_easy_strerror(res);
+            exit(1);
+        }
+        curl_easy_cleanup(curl);
+    }
+    return input_data(buffer, false);
+}
+
+int main (int argc, char* argv[]) {
+    Input input;
+    if (argc > 1) {
+        input = download(argv[1]);
+    } else {
+        input = input_data(cin, true);
+    }
+    auto bins = make_histogram(input.numbers, input.bin_count);
     show_histogram_svg(bins);
     return 0;
 }