code: Выполнен общий вариант

main.cpp

@@ -1,4 +1,6 @@
 #include <curl/curl.h>
+#include <sstream>
+#include <string>
 #include <iostream>
 #include <vector>
 #include "histogram.h"
@@ -29,27 +31,47 @@ input_data(istream& in, bool prompt){
     return in1;
 }
 
+static size_t
+write_data(void* items, size_t item_size, size_t item_count, void* ctx){
+    size_t data_size = item_size * item_count;
+    stringstream* buffer = reinterpret_cast<stringstream*>(ctx);
+    buffer->write(reinterpret_cast<const char*>(items), data_size);
+    return data_size;
+}
+
+Input
+download(const string& address) {
+    stringstream buffer;
+
+    curl_global_init(CURL_GLOBAL_ALL);
+    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);
+        curl_easy_cleanup(curl);
+        if (res != CURLE_OK) {
+            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
+            exit(1);
+        }
+    }
+
+    return input_data(buffer, false);
+}
+
 int
 main(int argc, char* argv[])
 {
-    curl_global_init(CURL_GLOBAL_ALL);
+    Input input;
     if (argc > 1) {
-        CURL *curl = curl_easy_init();
-        if(curl) {
-            CURLcode res;
-            curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
-            res = curl_easy_perform(curl);
-            curl_easy_cleanup(curl);
-            if (res != CURLE_OK) {
-                fprintf(stderr, "curl_easy_perform() failed: %s\n",
-                curl_easy_strerror(res));
-                exit(1);
-            }
-        }
-        return 0;
+        input = download(argv[1]);
+    } else {
+        input = input_data(cin, true);
     }
-    auto in = input_data(cin, false);
-    auto bins = make_histogram(in.numbers, in.bin_count);
+
+    const auto bins = make_histogram(input.numbers, input.bin_count);
     show_histogram_svg(bins);
     return 0;
 }