added length limit for _strlen

I wanted the limit specifier for strings (e.g. "%16.s") to be usable in situations when zero termination isn't guaranteed. As a simple fix I added lenght limitation to _strlen.

1 files changed, 4 insertions, 2 deletions

diff --git a/printf.c b/printf.c
index a04b42b..93a2f0f 100644
--- a/printf.c
+++ b/printf.c
@@ -141,10 +141,12 @@ static inline void _out_fct(char character, void* buffer, size_t idx, size_t max
 

 // internal strlen

 // \return The length of the string (excluding the terminating 0)

-static inline unsigned int _strlen(const char* str)

+//         limited by 'max' size if non-zero

+static inline unsigned int _strlen(const char* str, size_t max)

 {

   const char* s;

-  for (s = str; *s; ++s);

+  size_t n = max;

+  for (s = str; *s && (max?n--:1); ++s);

   return (unsigned int)(s - str);

 }