From 3bc331b9c5c202496e187823568ef2e287fb3b21 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sat, 21 Mar 2026 10:42:00 +0000
Subject: [PATCH] lib: c: io: add fcntl.h

---
 lib/libc/include/fcntl.h | 53 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 lib/libc/include/fcntl.h

diff --git a/lib/libc/include/fcntl.h b/lib/libc/include/fcntl.h
new file mode 100644
index 0000000..d590e14
--- /dev/null
+++ b/lib/libc/include/fcntl.h
@@ -0,0 +1,53 @@
+#ifndef FCNTL_H_
+#define FCNTL_H_
+
+#define O_RDONLY   0x0000 /* open for reading only */
+#define O_WRONLY   0x0001 /* open for writing only */
+#define O_RDWR     0x0002 /* open for reading and writing */
+#define O_ACCMODE  0x0003 /* mask for above modes */
+
+#define O_NONBLOCK 0x00000004 /* no delay */
+#define O_APPEND   0x00000008 /* set append mode */
+
+#define O_SHLOCK   0x00000010 /* open with shared file lock */
+#define O_EXLOCK   0x00000020 /* open with exclusive file lock */
+#define O_ASYNC    0x00000040 /* signal pgrp when data ready */
+#define O_FSYNC    O_SYNC     /* source compatibility: do not use */
+#define O_NOFOLLOW 0x00000100 /* don't follow symlinks */
+#define O_CREAT    0x00000200 /* create if nonexistant */
+#define O_TRUNC    0x00000400 /* truncate to zero length */
+#define O_EXCL     0x00000800 /* error if already exists */
+#define O_RESOLVE_BENEATH                                                      \
+	0x00001000 /* only for open(2), same value as FMARK                    \
+	            */
+
+#define O_EVTONLY                                                              \
+	0x00008000 /* descriptor requested for event notifications only */
+
+#define O_NOCTTY       0x00020000 /* don't assign controlling terminal */
+
+#define O_DIRECTORY    0x00100000
+#define O_SYMLINK      0x00200000 /* allow open of a symlink */
+
+#define O_CLOEXEC      0x01000000 /* implicitly set FD_CLOEXEC */
+
+#define O_NOFOLLOW_ANY 0x20000000 /* no symlinks allowed in path */
+
+#define O_EXEC         0x40000000             /* open file for execute only */
+#define O_SEARCH       (O_EXEC | O_DIRECTORY) /* open directory for search only */
+
+#define AT_FDCWD       -2
+
+#define AT_EACCESS     0x0010 /* Use effective ids in access check */
+#define AT_SYMLINK_NOFOLLOW                                                    \
+	0x0020                   /* Act on the symlink itself not the target */
+#define AT_SYMLINK_FOLLOW 0x0040 /* Act on target of symlink */
+#define AT_REMOVEDIR      0x0080 /* Path refers to directory */
+#define AT_REALDEV                                                             \
+	0x0200 /* Return real device inodes resides on for fstatat(2) */
+#define AT_FDONLY                                                              \
+	0x0400 /* Use only the fd and Ignore the path for fstatat(2) */
+#define AT_SYMLINK_NOFOLLOW_ANY                                                \
+	0x0800 /* Path should not contain any symlinks */
+
+#endif