#include <stddef.h>
+#define SAFE_READ_ERROR ((size_t) -1)
+
/* Read up to COUNT bytes at BUF from descriptor FD, retrying if interrupted.
- Return the actual number of bytes read, zero for EOF, or (size_t) -1
- for an error. */
+ Return the actual number of bytes read, zero for EOF, or SAFE_READ_ERROR
+ upon error. */
extern size_t safe_read (int fd, void *buf, size_t count);