C: Add sdprintf

README.MD

@@ -2,5 +2,5 @@
 Small code snippets that might prove useful again in the future.
 
 ## C
-* report: Easy to use report statement with log levels
-
+* report/: Easy to use report statement with log levels
+* sdprintf.c: sprintf to a dynamic buffer

c/sdprintf.c

@@ -0,0 +1,23 @@
+/*!
+ * \brief sdprintf printf to a dynamic buffer 
+ * \param buf The character buffer. Will append if not NULL;
+ * \param offset Should be set to strlen when continuing a string. Will be incremented automatically.
+ * \param __format printf format string
+ * \return the number of bytes written
+ */
+int sdprintf(char **buf, int *offset, const char *__restrict __format, ...)
+{
+	va_list vargs;
+	int len;
+
+	va_start(vargs, __format);
+	len = vsnprintf(NULL, 0, __format, vargs);
+	va_end(vargs);
+	*buf = realloc(*buf, *offset + len + 1);
+	va_start(vargs, __format);
+	len = vsprintf(*buf + *offset, __format, vargs);
+	va_end(vargs);
+
+	*offset += len;
+	return len;
+}