Another round of documentation.
Bug: N/A
Test: N/A
Change-Id: I1b818fbb36ddd6d084dee56828290c2717a0c9b0
diff --git a/libc/include/sys/ipc.h b/libc/include/sys/ipc.h
index dee7c8a..c81ec1a 100644
--- a/libc/include/sys/ipc.h
+++ b/libc/include/sys/ipc.h
@@ -26,8 +26,12 @@
* SUCH DAMAGE.
*/
-#ifndef _SYS_IPC_H
-#define _SYS_IPC_H
+#pragma once
+
+/**
+ * @file sys/ipc.h
+ * @brief System V IPC.
+ */
#include <sys/cdefs.h>
#include <sys/types.h>
@@ -42,8 +46,12 @@
__BEGIN_DECLS
+/**
+ * [ftok(3)](http://man7.org/linux/man-pages/man3/ftok.3.html) converts a path and id to a
+ * System V IPC key.
+ *
+ * Returns a key on success, and returns -1 and sets `errno` on failure.
+ */
key_t ftok(const char* __path, int __id);
__END_DECLS
-
-#endif