1 files changed, 3 insertions, 0 deletions
diff --git a/README.md b/README.md
index 2c16afd..6583269 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,9 @@ int printf(const char* format, ...);
 int sprintf(char* buffer, const char* format, ...);
 int snprintf(char* buffer, size_t count, const char* format, ...);
 int vsnprintf(char* buffer, size_t count, const char* format, va_list va);
+
+// write to output function (instead of buffer)
+int oprintf(void (*out)(char character), const char* format, ...);
 ```