lib: c: io: implement standard FILE and DIR interfaces

lib/libc/io/stdio/opendir.c

@@ -0,0 +1,30 @@
+#include "dir.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+extern struct __opaque_dir *opendir(const char *name)
+{
+	struct __opaque_dir *out = malloc(sizeof *out);
+	if (!out) {
+		__set_errno(ENOMEM);
+		return NULL;
+	}
+
+	memset(out, 0x0, sizeof *out);
+
+	int fd = open(name, O_RDONLY | O_DIRECTORY);
+	if (fd < 0) {
+		free(out);
+		return NULL;
+	}
+
+	out->d_flags = 0;
+	out->d_fd = fd;
+
+	return out;
+}