Replace sprintf with string_printf.

Fixes #33.
Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/syncfinder.cc

@@ -23,6 +23,7 @@
 
 using std::complex;
 using std::vector;
+using std::string;
 using std::min;
 
 void
@@ -274,7 +275,7 @@ SyncFinder::search_refine (const WavData& wav_data, Mode mode, vector<Score>& sy
 
   for (const auto& score : sync_scores)
     {
-      //printf ("%zd %s %f", score.index, find_closest_sync (score.index), score.quality);
+      //printf ("%zd %s %f", score.index, find_closest_sync (score.index).c_str(), score.quality);
 
       // refine match
       double best_quality       = score.quality;
@@ -298,7 +299,7 @@ SyncFinder::search_refine (const WavData& wav_data, Mode mode, vector<Score>& sy
                 }
             }
         }
-      //printf (" => refined: %zd %s %f\n", best_index, find_closest_sync (best_index), best_quality);
+      //printf (" => refined: %zd %s %f\n", best_index, find_closest_sync (best_index).c_str(), best_quality);
       if (best_quality > Params::sync_threshold2)
         result_scores.push_back (Score { best_index, best_quality, best_block_type });
     }
@@ -406,7 +407,7 @@ SyncFinder::sync_fft (const WavData& wav_data, size_t index, size_t frame_count,
     }
 }
 
-const char*
+string
 SyncFinder::find_closest_sync (size_t index)
 {
   int wm_length = (mark_data_frame_count() + mark_sync_frame_count()) * Params::frame_size;
@@ -423,7 +424,5 @@ SyncFinder::find_closest_sync (size_t index)
           best_error = error;
         }
     }
-  static char buffer[1024]; // this code is for debugging only, so this should be ok
-  sprintf (buffer, "n:%d offset:%d", best, int (index) - (wm_offset + best * wm_length));
-  return buffer;
+  return string_printf ("n:%d offset:%d", best, int (index) - (wm_offset + best * wm_length));
 }

src/syncfinder.hh

@@ -108,7 +108,7 @@ private:
                  std::vector<float>& fft_out_db,
                  std::vector<char>& have_frames,
                  const std::vector<char>& want_frames);
-  const char *find_closest_sync (size_t index);
+  std::string find_closest_sync (size_t index);
 };
 
 #endif

src/utils.cc

@@ -111,12 +111,8 @@ vec_to_hex_str (const vector<unsigned char>& vec)
 {
   string s;
   for (auto byte : vec)
-    {
-      char buffer[256];
+    s += string_printf ("%02x", byte);
 
-      sprintf (buffer, "%02x", byte);
-      s += buffer;
-    }
   return s;
 }