feat(printf): add user pointer to fctprintf()

Arbitrary user data can be passed to output function

1 files changed, 11 insertions, 8 deletions

diff --git a/printf.c b/printf.c
index aa34cbd..dec4555 100644
--- a/printf.c
+++ b/printf.c
@@ -77,6 +77,13 @@
 typedef void (*out_fct_type)(char character, char* buffer, size_t idx, size_t maxlen);

 

 

+// wrapper used as buffer

+typedef struct {

+  void (*fct)(char character, void* user);

+  void* user;

+} out_fct_wrap_type;

+

+

 // internal buffer output

 static inline void _out_buffer(char character, char* buffer, size_t idx, size_t maxlen)

 {

@@ -105,10 +112,8 @@ static inline void _out_char(char character, char* buffer, size_t idx, size_t ma
 static inline void _out_fct(char character, char* buffer, size_t idx, size_t maxlen)

 {

   (void)idx; (void)maxlen;

-  typedef struct tag_out_fct_wrap_type {

-    void (*fct)(char character);

-  } out_fct_wrap_type;

-  ((out_fct_wrap_type*)buffer)->fct(character);  // buffer is the output fct pointer

+  // buffer is the output fct pointer

+  ((out_fct_wrap_type*)buffer)->fct(character, ((out_fct_wrap_type*)buffer)->user);

 }

 

 

@@ -691,13 +696,11 @@ int vsnprintf(char* buffer, size_t count, const char* format, va_list va)
 }

 

 

-int fctprintf(void (*out)(char character), const char* format, ...)

+int fctprintf(void (*out)(char character, void* user), void* user, const char* format, ...)

 {

   va_list va;

   va_start(va, format);

-  const struct tag_out_fct_wrap {

-    void (*fct)(char character);

-  } out_fct_wrap = { out };

+  const out_fct_wrap_type out_fct_wrap = { out, user };

   const int ret = _vsnprintf(_out_fct, (char*)&out_fct_wrap, (size_t)-1, format, va);

   va_end(va);

   return ret;