#pragma once

// open(2) flags.
//
// These are the *Linux x86-64* values, and they have to be: every program in
// the userland is built against a libc that sends Linux flag values, and the
// kernel reads them with these constants. They disagreed for a long time, with
// results that looked like filesystem corruption rather than like a mistake --
// Linux O_APPEND (0x400) landed on SchOS's O_TRUNC, so `cmd >> file`
// truncated the file it was meant to extend, and Linux O_TRUNC (0x200) landed
// on O_CREATE, so `cmd > file` left whatever was past the new end in place.
// Neither failure pointed anywhere near a header.
//
// Do not tidy these into a neat sequence. They are an external interface.

#define O_RDONLY    0x000000
#define O_WRONLY    0x000001
#define O_RDWR      0x000002
#define O_ACCMODE   0x000003

#define O_CREATE    0x000040   /* Linux O_CREAT     (0100)     */
#define O_CREAT     O_CREATE   /* the spelling every program uses */
#define O_EXCL      0x000080   /* Linux O_EXCL      (0200)     */
#define O_NOCTTY    0x000100   /* Linux O_NOCTTY    (0400)     */
#define O_TRUNC     0x000200   /* Linux O_TRUNC     (01000)    */
#define O_APPEND    0x000400   /* Linux O_APPEND    (02000)    */
#define O_NONBLOCK  0x000800   /* Linux O_NONBLOCK  (04000); no-op here */
#define O_DIRECTORY 0x010000   /* Linux O_DIRECTORY (0200000)  */
#define O_NOFOLLOW  0x020000   /* Linux O_NOFOLLOW  (0400000)  */
#define O_CLOEXEC   0x080000   /* Linux O_CLOEXEC   (02000000) */

// SchOS-only, placed above every flag Linux defines so it can never be
// mistaken for one. 0x40000 was used before and collides with Linux O_NOATIME.
#define O_EXTENT    0x8000000  /* sparse-extent hint */

#define F_DUPFD          0
#define F_GETFD          1
#define F_SETFD          2
#define F_GETFL          3
#define F_SETFL          4
#define F_DUPFD_CLOEXEC  1030  // Linux value

#define FD_CLOEXEC 1