--- /dev/null
+#ifndef SYS_UIO_H\r
+#define SYS_UIO_H\r
+\r
+#include <inttypes.h>\r
+#include <unistd.h>\r
+\r
+ struct iovec\r
+ {\r
+ void *iov_base; //Base address of a memory region for input or output.\r
+ size_t iov_len; //The size of the memory pointed to by iov_base.\r
+};\r
+\r
+ ssize_t readv(int fildes, const struct iovec *iov, int iovcnt);\r
+ ssize_t writev(int fildes, const struct iovec *iov, int iovcnt);\r
+\r
+#endif /* SYS_UIO_H */\r