--- /dev/null
+#ifndef STDIO_H_
+#define STDIO_H_
+
+#include <stdlib.h>
+#include <stdarg.h>
+
+int putchar(int c);
+int puts(const char *s);
+
+int printf(const char *fmt, ...);
+int vprintf(const char *fmt, va_list ap);
+
+int sprintf(char *buf, const char *fmt, ...);
+int vsprintf(char *buf, const char *fmt, va_list ap);
+
+int snprintf(char *buf, size_t sz, const char *fmt, ...);
+int vsnprintf(char *buf, size_t sz, const char *fmt, va_list ap);
+
+#endif /* STDIO_H_ */