code: сохранение данных в буфер

main.cpp

@@ -1,5 +1,7 @@
 #include <iostream>
 #include <vector>
+#include <sstream>
+#include <string>
 #include <curl/curl.h>
 #include "histogram.h"
 #include "svg.h"
@@ -33,13 +35,22 @@ input_data(istream& stream, bool prompt)
     return in;
 }
 
-int main(int argc, char* argv[])
+size_t write_data(void* items, size_t item_size, size_t item_count, void* ctx)
 {
-    if (argc > 1) {
+    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* curl = curl_easy_init();
         if (curl) {
             CURLcode res;
-            curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
+            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 != CURLE_OK) {
                 fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
@@ -47,10 +58,17 @@ int main(int argc, char* argv[])
             }
             curl_easy_cleanup(curl);
         }
-        return 0;
+    return input_data(buffer, false);
 }
-    curl_global_init(CURL_GLOBAL_ALL);
-    Input in = input_data(cin, true);
-    vector<size_t> bins = make_histogram(in.numbers, in.bin_count);
+
+int main(int argc, char* argv[]) {
+    Input input;
+    if (argc > 1) {
+            input = download(argv[1]);
+    }
+    else {
+        input = input_data(cin, true);
+    }
+    vector<size_t> bins = make_histogram(input.numbers, input.bin_count);
     show_histogram_svg(bins);
 }