Provide string_printf helper.

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

src/utils.cc

@@ -108,6 +108,35 @@ vec_to_hex_str (const vector<unsigned char>& vec)
   return s;
 }
 
+static string
+string_vprintf (const char *format, va_list vargs)
+{
+  string s;
+
+  char *str = NULL;
+  if (vasprintf (&str, format, vargs) >= 0 && str)
+    {
+      s = str;
+      free (str);
+    }
+  else
+    s = format;
+
+  return s;
+}
+
+string
+string_printf (const char *format, ...)
+{
+  va_list ap;
+
+  va_start (ap, format);
+  string s = string_vprintf (format, ap);
+  va_end (ap);
+
+  return s;
+}
+
 static Log log_level = Log::INFO;
 
 void
@@ -121,12 +150,10 @@ logv (Log log, const char *format, va_list vargs)
 {
   if (log >= log_level)
     {
-      char buffer[1024];
-
-      vsnprintf (buffer, sizeof (buffer), format, vargs);
+      string s = string_vprintf (format, vargs);
 
       /* could support custom log function here */
-      fprintf (stderr, "%s", buffer);
+      fprintf (stderr, "%s", s.c_str());
       fflush (stderr);
     }
 }

src/utils.hh

@@ -58,6 +58,8 @@ enum class Log { ERROR = 3, WARNING = 2, INFO = 1, DEBUG = 0 };
 
 void set_log_level (Log level);
 
+std::string string_printf (const char *fmt, ...) AUDIOWMARK_PRINTF (1, 2);
+
 class Error
 {
 public: