feat(dirent): directory iteration

src/dirent/rewinddir.c

@@ -0,0 +1,29 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <dirent.h>
+
+#include <unistd.h>
+
+#include "../internal/syscall.h"
+#include "dirent_impl.h"
+
+/*
+ * rewinddir (todo 24): return the stream to the start of the directory.
+ * SYS_lseek back to offset 0 resets the kernel's per-fd directory
+ * position; the cached records (if any) are dropped and the stored seek
+ * cookie is reset, so the next readdir refills from the first entry.
+ * rewinddir has no error return; a failed lseek leaves the stream
+ * positioned wherever the kernel is.
+ */
+void
+rewinddir(DIR *dir)
+{
+    struct vlibc_DIR *d = dir;
+
+    syscall_ret(__syscall3(SYS_lseek, d->fd, 0, SEEK_SET));
+    d->buf_pos = 0;
+    d->buf_end = 0;
+    d->de.d_off = 0;
+}