/**
 * D header file for POSIX.
 *
 * Copyright: Copyright Sean Kelly 2005 - 2009.
 * License:   $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
 * Authors:   Sean Kelly, Alex Rønne Petersen
 * Standards: The Open Group Base Specifications Issue 6, IEEE Std 1003.1, 2004 Edition
 */

/*          Copyright Sean Kelly 2005 - 2009.
 * Distributed under the Boost Software License, Version 1.0.
 *    (See accompanying file LICENSE or copy at
 *          http://www.boost.org/LICENSE_1_0.txt)
 */
module core.sys.posix.fcntl;

import core.sys.posix.config;
import core.stdc.stdint;
public import core.sys.posix.sys.types; // for off_t, mode_t
public import core.sys.posix.sys.stat;  // for S_IFMT, etc.

version (OSX)
    version = Darwin;
else version (iOS)
    version = Darwin;
else version (TVOS)
    version = Darwin;
else version (WatchOS)
    version = Darwin;

version (ARM)     version = ARM_Any;
version (AArch64) version = ARM_Any;
version (HPPA)    version = HPPA_Any;
version (MIPS32)  version = MIPS_Any;
version (MIPS64)  version = MIPS_Any;
version (PPC)     version = PPC_Any;
version (PPC64)   version = PPC_Any;
version (RISCV32) version = RISCV_Any;
version (RISCV64) version = RISCV_Any;
version (S390)    version = IBMZ_Any;
version (SPARC)   version = SPARC_Any;
version (SPARC64) version = SPARC_Any;
version (SystemZ) version = IBMZ_Any;
version (X86)     version = X86_Any;
version (X86_64)  version = X86_Any;

version (Posix):
extern (C):

nothrow:
@nogc:

//
// Required
//
/*
F_DUPFD
F_GETFD
F_SETFD
F_GETFL
F_SETFL
F_GETLK
F_SETLK
F_SETLKW
F_GETOWN
F_SETOWN

FD_CLOEXEC

F_RDLCK
F_UNLCK
F_WRLCK

O_CREAT
O_EXCL
O_NOCTTY
O_TRUNC

O_APPEND
O_DSYNC
O_NONBLOCK
O_RSYNC
O_SYNC

O_ACCMODE
O_RDONLY
O_RDWR
O_WRONLY

struct flock
{
    short   l_type;
    short   l_whence;
    off_t   l_start;
    off_t   l_len;
    pid_t   l_pid;
}
*/
version (linux)
{
    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
  version (X86_64)
  {
    static assert(off_t.sizeof == 8);
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
  else version (AArch64)
  {
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
  else version (PPC64)
  {
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
  else version (RISCV64)
  {
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
  else version (SystemZ)
  {
    static assert(off_t.sizeof == 8);
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
  else version (MIPS_N64)
  {
    enum F_GETLK        = 14;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
  else version (MIPS_Any)
  {
    static if ( __USE_FILE_OFFSET64 )
    {
      enum F_GETLK      = 33;
      enum F_SETLK      = 34;
      enum F_SETLKW     = 35;
    }
    else
    {
      enum F_GETLK      = 14;
      enum F_SETLK      = 6;
      enum F_SETLKW     = 7;
    }
  }
  else version (LoongArch64)
  {
    static assert(off_t.sizeof == 8);
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  } else
  static if ( __USE_FILE_OFFSET64 )
  {
    enum F_GETLK        = 12;
    enum F_SETLK        = 13;
    enum F_SETLKW       = 14;
  }
  else
  {
    enum F_GETLK        = 5;
    enum F_SETLK        = 6;
    enum F_SETLKW       = 7;
  }
    enum F_GETOWN       = 9;
    enum F_SETOWN       = 8;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 0;
    enum F_UNLCK        = 2;
    enum F_WRLCK        = 1;

    version (X86_Any)
    {
        enum O_CREAT        = 0x40;     // octal     0100
        enum O_EXCL         = 0x80;     // octal     0200
        enum O_NOCTTY       = 0x100;    // octal     0400
        enum O_TRUNC        = 0x200;    // octal    01000

        enum O_APPEND       = 0x400;    // octal    02000
        enum O_NONBLOCK     = 0x800;    // octal    04000
        enum O_CLOEXEC      = 0x80000;  // octal 02000000
        enum O_SYNC         = 0x101000; // octal 04010000
        enum O_DSYNC        = 0x1000;   // octal   010000
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x010000; // octal   0200000
        enum O_NOFOLLOW     = 0x020000; // octal   0400000
        enum O_DIRECT       = 0x004000; // octal    040000
        version (X86_64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x08000; // octal   0100000
        enum O_TMPFILE      = 0x410000; // octal 020200000
        enum O_ASYNC        = 0x2000;   // octal    020000
        enum O_NOATIME      = 0x40000;  // octal  01000000
        enum O_PATH         = 0x200000; // octal 010000000
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (HPPA_Any)
    {
        enum O_CREAT        = 0x00100;  // octal    04000
        enum O_EXCL         = 0x00400;  // octal     0200
        enum O_NOCTTY       = 0x20000;  // octal     0400
        enum O_TRUNC        = 0x00200;  // octal    01000

        enum O_APPEND       = 0x00008;  // octal      010
        enum O_NONBLOCK     = 0x10004;  // octal  0200004
        enum O_CLOEXEC      = 0x200000; // octal 02000000
        enum O_SYNC         = 0x48000;  // octal 01100000
        enum O_DSYNC        = 0x40000;  // octal 01000000
        enum O_RSYNC        = 0x80000;  // octal 02000000

        enum O_DIRECTORY    = 0x001000; // octal 000010000
        enum O_NOFOLLOW     = 0x000080; // octal 000000200
        enum O_DIRECT       = 0x004000; // octal    040000
        enum O_LARGEFILE    = 0x000800; // octal  00004000
        enum O_TMPFILE      = 0x801000; // octal 040010000
        enum O_ASYNC        = 0x2000;   // octal    020000
        enum O_NOATIME      = 0x100000; // octal 004000000
        enum O_PATH         = 0x400000; // octal 020000000
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (MIPS_Any)
    {
        enum O_CREAT        = 0x0100;
        enum O_EXCL         = 0x0400;
        enum O_NOCTTY       = 0x0800;
        enum O_TRUNC        = 0x0200;

        enum O_APPEND       = 0x0008;
        enum O_DSYNC        = 0x0010;
        enum O_NONBLOCK     = 0x0080;
        enum O_CLOEXEC      = 0x80000;
        enum O_RSYNC        = O_SYNC;
        enum O_SYNC         = 0x4010;

        enum O_DIRECTORY    = 0x010000;
        enum O_NOFOLLOW     = 0x020000;
        enum O_DIRECT       = 0x8000;
        version (MIPS_N64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x2000;
        enum O_TMPFILE      = 0x410000;
        enum O_ASYNC        = 0x1000;
        enum O_NOATIME      = 0x40000;
        enum O_PATH         = 0x200000;
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (PPC_Any)
    {
        enum O_CREAT        = 0x40;     // octal     0100
        enum O_EXCL         = 0x80;     // octal     0200
        enum O_NOCTTY       = 0x100;    // octal     0400
        enum O_TRUNC        = 0x200;    // octal    01000

        enum O_APPEND       = 0x400;    // octal    02000
        enum O_NONBLOCK     = 0x800;    // octal    04000
        enum O_CLOEXEC      = 0x80000;  // octal 02000000
        enum O_SYNC         = 0x101000; // octal 04010000
        enum O_DSYNC        = 0x1000;   // octal   010000
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x004000; // octal    040000
        enum O_NOFOLLOW     = 0x008000; // octal   0100000
        enum O_DIRECT       = 0x020000; // octal   0400000
        version (D_LP64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x10000; // octal   0200000
        enum O_TMPFILE      = 0x404000; // octal 020040000
        enum O_ASYNC        = 0x2000;   // octal    020000
        enum O_NOATIME      = 0x40000;  // octal  01000000
        enum O_PATH         = 0x200000;
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (ARM_Any)
    {
        enum O_CREAT        = 0x40;     // octal     0100
        enum O_EXCL         = 0x80;     // octal     0200
        enum O_NOCTTY       = 0x100;    // octal     0400
        enum O_TRUNC        = 0x200;    // octal    01000

        enum O_APPEND       = 0x400;    // octal    02000
        enum O_NONBLOCK     = 0x800;    // octal    04000
        enum O_CLOEXEC      = 0x80000;  // octal 02000000
        enum O_SYNC         = 0x101000; // octal 04010000
        enum O_DSYNC        = 0x1000;   // octal   010000
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x004000; // octal    040000
        enum O_NOFOLLOW     = 0x008000; // octal   0100000
        enum O_DIRECT       = 0x010000; // octal   0200000
        version (D_LP64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x20000; // octal   0400000
        enum O_TMPFILE      = 0x404000; // octal 020040000
        enum O_ASYNC        = 0x2000;   // octal    020000
        enum O_NOATIME      = 0x40000;  // octal  01000000
        enum O_PATH         = 0x200000; // octal 010000000
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (RISCV_Any)
    {
        enum O_CREAT        = 0x40;     // octal     0100
        enum O_EXCL         = 0x80;     // octal     0200
        enum O_NOCTTY       = 0x100;    // octal     0400
        enum O_TRUNC        = 0x200;    // octal    01000

        enum O_APPEND       = 0x400;    // octal    02000
        enum O_NONBLOCK     = 0x800;    // octal    04000
        enum O_CLOEXEC      = 0x80000;  // octal 02000000
        enum O_SYNC         = 0x101000; // octal 04010000
        enum O_DSYNC        = 0x1000;   // octal   010000
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x010000;
        enum O_NOFOLLOW     = 0x020000;
        enum O_DIRECT       = 0x004000;
        version (D_LP64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x8000;
        enum O_TMPFILE      = 0x410000;
        enum O_ASYNC        = 0x2000;
        enum O_NOATIME      = 0x40000;
        enum O_PATH         = 0x200000;
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (SPARC_Any)
    {
        enum O_CREAT        = 0x200;
        enum O_EXCL         = 0x800;
        enum O_NOCTTY       = 0x8000;
        enum O_TRUNC        = 0x400;

        enum O_APPEND       = 0x8;
        enum O_NONBLOCK     = 0x4000;
        enum O_CLOEXEC      = 0x400000;
        enum O_SYNC         = 0x802000;
        enum O_DSYNC        = 0x2000;
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x10000;
        enum O_NOFOLLOW     = 0x20000;
        enum O_DIRECT       = 0x100000;
        version (D_LP64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x40000;
        enum O_TMPFILE      = 0x2010000;
        enum O_ASYNC        = 0x0040;
        enum O_NOATIME      = 0x200000;
        enum O_PATH         = 0x1000000;
        enum O_NDELAY       = (0x0004|O_NONBLOCK);
    }
    else version (IBMZ_Any)
    {
        enum O_CREAT        = 0x40;     // octal     0100
        enum O_EXCL         = 0x80;     // octal     0200
        enum O_NOCTTY       = 0x100;    // octal     0400
        enum O_TRUNC        = 0x200;    // octal    01000

        enum O_APPEND       = 0x400;    // octal    02000
        enum O_NONBLOCK     = 0x800;    // octal    04000
        enum O_CLOEXEC      = 0x80000;  // octal 02000000
        enum O_SYNC         = 0x101000; // octal 04010000
        enum O_DSYNC        = 0x1000;   // octal   010000
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x010000; // octal   0200000
        enum O_NOFOLLOW     = 0x020000; // octal   0400000
        enum O_DIRECT       = 0x004000; // octal    040000
        version (D_LP64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x08000; // octal   0100000
        enum O_TMPFILE      = 0x410000; // octal 020200000
        enum O_ASYNC        = 0x2000;   // octal    020000
        enum O_NOATIME      = 0x40000;  // octal  01000000
        enum O_PATH         = 0x200000; // octal 010000000
        enum O_NDELAY       = O_NONBLOCK;
    }
    else version (LoongArch64)
    {
        enum O_CREAT        = 0x40;     // octal     0100
        enum O_EXCL         = 0x80;     // octal     0200
        enum O_NOCTTY       = 0x100;    // octal     0400
        enum O_TRUNC        = 0x200;    // octal    01000

        enum O_APPEND       = 0x400;    // octal    02000
        enum O_NONBLOCK     = 0x800;    // octal    04000
        enum O_CLOEXEC      = 0x80000;  // octal 02000000
        enum O_SYNC         = 0x101000; // octal 04010000
        enum O_DSYNC        = 0x1000;   // octal   010000
        enum O_RSYNC        = O_SYNC;

        enum O_DIRECTORY    = 0x010000; // octal    200000
        enum O_NOFOLLOW     = 0x020000; // octal    400000
        enum O_DIRECT       = 0x004000; // octal    040000
        version (D_LP64)
            enum O_LARGEFILE = 0;
        else
            enum O_LARGEFILE = 0x8000;  // octal   0100000
        enum O_TMPFILE      = 0x404000; // octal 020040000
        enum O_ASYNC        = 0x2000;   // octal    020000
        enum O_NOATIME      = 0x40000;  // octal  01000000
        enum O_PATH         = 0x200000; // octal 010000000
        enum O_NDELAY       = O_NONBLOCK;
    }
    else
        static assert(0, "unimplemented");

    version (CRuntime_Musl)
    {
        enum O_SEARCH   = O_PATH;
        enum O_EXEC     = O_PATH;
        enum O_ACCMODE  = (3|O_SEARCH);
    }
    else
    {
        enum O_ACCMODE  = 0x3;
    }
    enum O_RDONLY       = 0x0;
    enum O_WRONLY       = 0x1;
    enum O_RDWR         = 0x2;

    struct flock
    {
        short   l_type;
        short   l_whence;
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
    }

    enum AT_SYMLINK_NOFOLLOW = 0x100;
    enum AT_FDCWD = -100;
    enum AT_REMOVEDIR = 0x200;
    enum AT_SYMLINK_FOLLOW = 0x400;
    enum AT_EACCESS = 0x200;
}
else version (Darwin)
{
    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
    enum F_GETOWN       = 5;
    enum F_SETOWN       = 6;
    enum F_GETLK        = 7;
    enum F_SETLK        = 8;
    enum F_SETLKW       = 9;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 1;
    enum F_UNLCK        = 2;
    enum F_WRLCK        = 3;

    enum O_NOFOLLOW     = 0x0100;
    enum O_CREAT        = 0x0200;
    enum O_EXCL         = 0x0800;
    enum O_NOCTTY       = 0;
    enum O_TRUNC        = 0x0400;

    enum O_RDONLY       = 0x0000;
    enum O_WRONLY       = 0x0001;
    enum O_RDWR         = 0x0002;
    enum O_ACCMODE      = 0x0003;

    enum O_NONBLOCK     = 0x0004;
    enum O_APPEND       = 0x0008;
    enum O_SYNC         = 0x0080;
    //enum O_DSYNC
    //enum O_RSYNC

    struct flock
    {
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
        short   l_type;
        short   l_whence;
    }

    enum AT_FDCWD = -2;
    enum AT_EACCESS          = 0x0010;
    enum AT_SYMLINK_NOFOLLOW = 0x0020;
    enum AT_SYMLINK_FOLLOW   = 0x0040;
    enum AT_REMOVEDIR        = 0x0080;
}
else version (FreeBSD)
{
    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
    enum F_GETOWN       = 5;
    enum F_SETOWN       = 6;
    enum F_GETLK        = 11;
    enum F_SETLK        = 12;
    enum F_SETLKW       = 13;
    enum F_OGETLK       = 7;
    enum F_OSETLK       = 8;
    enum F_OSETLKW      = 9;
    enum F_DUP2FD       = 10;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 1;
    enum F_UNLCK        = 2;
    enum F_WRLCK        = 3;

    enum O_CREAT        = 0x0200;
    enum O_EXCL         = 0x0800;
    enum O_NOCTTY       = 0x8000;
    enum O_TRUNC        = 0x0400;

    enum O_RDONLY       = 0x0000;
    enum O_WRONLY       = 0x0001;
    enum O_RDWR         = 0x0002;
    enum O_ACCMODE      = 0x0003;

    enum O_NONBLOCK     = 0x0004;
    enum O_APPEND       = 0x0008;
    enum O_SYNC         = 0x0080;
    //enum O_DSYNC
    //enum O_RSYNC

    struct flock
    {
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
        short   l_type;
        short   l_whence;
        int     l_sysid;
    }

    struct oflock
    {
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
        short   l_type;
        short   l_whence;
    }

    enum AT_FDCWD = -100;
    enum AT_EACCESS          = 0x100;
    enum AT_SYMLINK_NOFOLLOW = 0x200;
    enum AT_SYMLINK_FOLLOW   = 0x400;
    enum AT_REMOVEDIR        = 0x800;
}
else version (OpenBSD)
{
    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
    enum F_GETOWN       = 5;
    enum F_SETOWN       = 6;
    enum F_GETLK        = 7;
    enum F_SETLK        = 8;
    enum F_SETLKW       = 9;
    enum F_DUPFD_CLOEXEC= 10;
    enum F_ISATTY       = 11;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 1;
    enum F_UNLCK        = 2;
    enum F_WRLCK        = 3;

    enum O_CREAT        = 0x0200;
    enum O_EXCL         = 0x0800;
    enum O_NOCTTY       = 0x8000;
    enum O_TRUNC        = 0x0400;

    enum O_RDONLY       = 0x0000;
    enum O_WRONLY       = 0x0001;
    enum O_RDWR         = 0x0002;
    enum O_ACCMODE      = 0x0003;
    enum O_SHLOCK       = 0x0010;
    enum O_EXLOCK       = 0x0020;
    enum O_ASYNC        = 0x0040;
    enum O_FSYNC        = 0x0080;
    enum O_NOFOLLOW     = 0x0100;

    enum O_NONBLOCK     = 0x0004;
    enum O_APPEND       = 0x0008;
    enum O_SYNC         = 0x0080;
    enum O_DSYNC        = O_SYNC;
    enum O_RSYNC        = O_SYNC;

    enum O_CLOEXEC      = 0x10000;
    enum O_DIRECTORY    = 0x20000;

    enum LOCK_SH        = 0x01;
    enum LOCK_EX        = 0x02;
    enum LOCK_NB        = 0x04;
    enum LOCK_UN        = 0x08;

    struct flock
    {
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
        short   l_type;
        short   l_whence;
    }

    enum AT_FDCWD            = -100;

    enum AT_EACCESS          = 0x01;
    enum AT_SYMLINK_NOFOLLOW = 0x02;
    enum AT_SYMLINK_FOLLOW   = 0x04;
    enum AT_REMOVEDIR        = 0x08;
}
else version (NetBSD)
{
    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
    enum F_GETOWN       = 5;
    enum F_SETOWN       = 6;
    enum F_GETLK        = 7;
    enum F_SETLK        = 8;
    enum F_SETLKW       = 9;
    enum F_CLOSEM       = 10;
    enum F_MAXFD        = 11;
    enum F_DUPFD_CLOEXEC= 12;
    enum F_GETNOSIGPIPE = 13;
    enum F_SETNOSIGPIPE = 14;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 1;
    enum F_UNLCK        = 2;
    enum F_WRLCK        = 3;

    enum O_CREAT        = 0x0200;
    enum O_EXCL         = 0x0800;
    enum O_NOCTTY       = 0x8000;
    enum O_TRUNC        = 0x0400;

    enum O_RDONLY       = 0x0000;
    enum O_WRONLY       = 0x0001;
    enum O_RDWR         = 0x0002;
    enum O_ACCMODE      = 0x0003;

    enum O_NONBLOCK     = 0x0004;
    enum O_APPEND       = 0x0008;
    enum O_SYNC         = 0x0080;
    //enum O_DSYNC
    //enum O_RSYNC

    struct flock
    {
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
        short   l_type;
        short   l_whence;
    }

    enum AT_FDCWD = -100;
    enum AT_EACCESS          = 0x100;
    enum AT_SYMLINK_NOFOLLOW = 0x200;
    enum AT_SYMLINK_FOLLOW   = 0x400;
    enum AT_REMOVEDIR        = 0x800;
}
else version (DragonFlyBSD)
{
    enum O_RDONLY       = 0x0000;
    enum O_WRONLY       = 0x0001;
    enum O_RDWR         = 0x0002;
    enum O_ACCMODE      = 0x0003;

    enum FREAD          = 0x0001;
    enum FWRITE         = 0x0002;
    enum O_NONBLOCK     = 0x0000004;
    enum O_APPEND       = 0x0000008;
    enum O_SHLOCK       = 0x0000010;
    enum O_EXLOCK       = 0x0000020;
    enum O_ASYNC        = 0x0000040;
    enum O_FSYNC        = 0x0000080;
    enum O_SYNC         = 0x0000080;
    enum O_NOFOLLOW     = 0x0000100;
    enum O_CREAT        = 0x0000200;
    enum O_TRUNC        = 0x0000400;
    enum O_EXCL         = 0x0000800;
    enum O_NOCTTY       = 0x0008000;
    enum O_DIRECT       = 0x0010000;
    enum O_CLOEXEC      = 0x0020000;
    enum O_FBLOCKING    = 0x0040000;
    enum O_FNONBLOCKING = 0x0080000;
    enum O_FAPPEND      = 0x0100000;
    enum O_FOFFSET      = 0x0200000;
    enum O_FSYNCWRITE   = 0x0400000;
    enum O_FASYNCWRITE  = 0x0800000;
    enum O_DIRECTORY    = 0x8000000;

    enum FAPPEND        = O_APPEND;
    enum FASYNC         = O_ASYNC;
    enum FFSYNC         = O_FSYNC;
    enum FNONBLOCK      = O_NONBLOCK;
    enum FNDELAY        = O_NONBLOCK;
    enum O_NDELAY       = O_NONBLOCK;
    enum FPOSIXSHM      = O_NOFOLLOW;

    enum FCNTLFLAGS = (FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|O_DIRECT);

    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
    enum F_GETOWN       = 5;
    enum F_SETOWN       = 6;
    enum F_GETLK        = 7;
//    enum F_SETLK        = 8;
    enum F_SETLK        = 8;
    enum F_SETLKW       = 9;
    enum F_OGETLK       = F_GETLK;
    enum F_OSETLK       = F_SETLK;
    enum F_OSETLKW      = F_SETLKW;
    enum F_DUP2FD       = 10;
    //enum F_GETLK        = 11;
    //enum F_SETLK        = 12;
    //enum F_SETLKW       = 13;
    enum F_DUPFD_CLOEXEC = 17;
    enum F_DUP2FD_CLOEXEC = 18;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 1;
    enum F_UNLCK        = 2;
    enum F_WRLCK        = 3;

    enum LOCK_SH        = 0x01;
    enum LOCK_EX        = 0x02;
    enum LOCK_NB        = 0x04;
    enum LOCK_UN        = 0x08;

    struct flock
    {
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
        short   l_type;
        short   l_whence;
    }

    alias oflock = flock;

    enum AT_FDCWD = 0xFFFAFDCD;
    enum AT_SYMLINK_NOFOLLOW = 1;
    enum AT_REMOVEDIR        = 2;
    enum AT_EACCESS          = 4;
    enum AT_SYMLINK_FOLLOW   = 8;
}
else version (Solaris)
{
    enum F_DUPFD = 0;
    enum F_GETFD = 1;
    enum F_SETFD = 2;
    enum F_GETFL = 3;
    enum F_SETFL = 4;

    version (D_LP64)
    {
        enum F_GETLK = 14;
        enum F_SETLK = 6;
        enum F_SETLKW = 7;
    }
    else
    {
        static if (__USE_FILE_OFFSET64)
        {
            enum F_GETLK = 14;
            enum F_SETLK = 6;
            enum F_SETLKW = 7;
        }
        else
        {
            enum F_GETLK = 33;
            enum F_SETLK = 34;
            enum F_SETLKW = 35;
        }
    }

    enum F_GETOWN = 23;
    enum F_SETOWN = 24;

    enum FD_CLOEXEC = 1;

    enum F_RDLCK = 1;
    enum F_UNLCK = 3;
    enum F_WRLCK = 2;
    enum F_UNCKSYS = 4;

    enum O_CREAT = 0x0100;
    enum O_EXCL = 0x0400;
    enum O_NOCTTY = 0x0800;
    enum O_TRUNC = 0x0200;

    enum O_APPEND = 0x0008;
    enum O_NONBLOCK = 0x0080;
    enum O_SYNC = 0x0010;
    enum O_DSYNC = 0x0040;
    enum O_RSYNC = 0x8000;

    enum O_ACCMODE = (O_SEARCH | O_EXEC | 0x3);
    enum O_RDONLY = 0;
    enum O_WRONLY = 1;
    enum O_RDWR = 2;
    enum O_SEARCH = 0x200000;
    enum O_EXEC = 0x400000;

    struct flock
    {
        short l_type;
        short l_whence;
        off_t l_start;
        off_t l_len;
        int l_sysid;
        pid_t l_pid;
        c_long[4] l_pad;
    }

    static if (__USE_LARGEFILE64)
    {
        struct flock64
        {
            short       l_type;
            short       l_whence;
            off64_t     l_start;
            off64_t     l_len;
            int         l_sysid;
            pid_t       l_pid;
            c_long[4]   l_pad;
        }
    }
    enum AT_FDCWD = -3041965;
    enum AT_SYMLINK_NOFOLLOW = 0x1000;
    enum AT_SYMLINK_FOLLOW   = 0x2000;
    enum AT_REMOVEDIR        = 0x1;
    enum AT_EACCESS          = 0x4;
}
else version (Hurd)
{
    enum F_DUPFD        = 0;
    enum F_GETFD        = 1;
    enum F_SETFD        = 2;
    enum F_GETFL        = 3;
    enum F_SETFL        = 4;
    enum F_GETOWN       = 5;
    enum F_SETOWN       = 6;

    static if ( __USE_FILE_OFFSET64 )
    {
        enum F_GETLK      = F_GETLK64;
        enum F_SETLK      = F_SETLK64;
        enum F_SETLKW     = F_SETLKW64;
    }
    else
    {
        enum F_GETLK      = 7;
        enum F_SETLK      = 8;
        enum F_SETLKW     = 9;
    }
    enum F_GETLK64        = 10;
    enum F_SETLK64        = 11;
    enum F_SETLKW64       = 12;

    enum F_DUPFD_CLOEXEC = 1030;

    enum FD_CLOEXEC     = 1;

    enum F_RDLCK        = 1;
    enum F_WRLCK        = 2;
    enum F_UNLCK        = 3;

    enum O_CREAT        = 0x0010;
    enum O_EXCL         = 0x0020;
    enum O_NOCTTY       = 0;
    enum O_TRUNC        = 0x00010000;

    enum O_APPEND       = 0x0100;
    enum O_DSYNC        = O_SYNC;
    enum O_NONBLOCK     = 0x0004;
    enum O_RSYNC        = O_SYNC;


    enum O_ACCMODE      = O_RDWR;
    enum O_RDONLY       = 0x0001;
    enum O_WRONLY       = 0x0002;
    enum O_RDWR         = (O_RDONLY|O_WRONLY);

    enum O_SYNC         = O_FSYNC;
    enum O_FSYNC        = 0x0400;

    enum O_READ         = O_RDONLY;
    enum O_WRITE        = O_WRONLY;
    enum O_EXEC         = 0x0004;
    enum O_NORW         = 0;
    enum O_LARGEFILE    = 0;
    enum O_NOLINK       = 0x0040;
    enum O_NOTRANS      = 0x0080;
    enum O_NOFOLLOW     = 0x00100000;
    enum O_DIRECTORY    = 0x00200000;
    enum O_ASYNC        = 0x0200;
    enum O_NOATIME      = 0x0800;
    enum O_SHLOCK       = 0x00020000;
    enum O_EXLOCK       = 0x00040000;
    enum O_NDELAY       = O_NONBLOCK;
    enum O_HURD         = (0xffff | O_EXLOCK | O_SHLOCK);
    enum O_CLOEXEC      = 0x00400000;
    enum O_TMPFILE      = 0x00800000;
    enum O_IGNORE_CTTY  = 0x00080000;


    version (X86)
    {
        struct flock
        {
            int     l_type;
            int     l_whence;
            off_t   l_start;
            off_t   l_len;
            pid_t   l_pid;
        }
    }
    else version (X86_64)
    {
        struct flock
        {
            short   l_type;
            short   l_whence;
            off_t   l_start;
            off_t   l_len;
            pid_t   l_pid;
        }
    }
    else
    {
        static assert(false, "Unsupported platform");
    }

    enum AT_FDCWD            = -100;

    enum AT_EACCESS          = 0x200;
    enum AT_SYMLINK_NOFOLLOW = 0x100;
    enum AT_SYMLINK_FOLLOW   = 0x400;
    enum AT_REMOVEDIR        = 0x200;
}
else version (CRuntime_WASI)
{
    enum F_GETFD         = 1;
    enum F_SETFD         = 2;
    enum F_GETFL         = 3;
    enum F_SETFL         = 4;
    enum F_DUPFD         = 5;
    enum F_DUPFD_CLOEXEC = 6;
    enum F_GETLK         = 7;
    enum F_SETLK         = 8;
    enum F_SETLKW        = 9;

    enum F_RDLCK         = 0;
    enum F_WRLCK         = 1;
    enum F_UNLCK         = 2;

    enum FD_CLOEXEC      = 1;

    enum O_APPEND    = 0x0001;
    enum O_DSYNC     = 0x0002;
    enum O_NONBLOCK  = 0x0004;
    enum O_RSYNC     = 0x0008;
    enum O_SYNC      = 0x0010;
    enum O_CREAT     = 0x0001 << 12;
    enum O_DIRECTORY = 0x0002 << 12;
    enum O_EXCL      = 0x0004 << 12;
    enum O_TRUNC     = 0x0008 << 12;

    enum O_NOFOLLOW = 0x01000000;
    enum O_EXEC     = 0x02000000;
    enum O_RDONLY   = 0x04000000;
    enum O_SEARCH   = 0x08000000;
    enum O_WRONLY   = 0x10000000;

    enum O_CLOEXEC = 0;

    enum O_TTY_INIT = 0;

    enum O_NOCTTY = 0;

    enum O_RDWR = O_RDONLY | O_WRONLY;
    enum O_ACCMODE = O_EXEC | O_RDWR | O_SEARCH;

    struct flock
    {
        short   l_type;
        short   l_whence;
        off_t   l_start;
        off_t   l_len;
        pid_t   l_pid;
    }

    enum AT_EACCESS          = 0x0;
    enum AT_SYMLINK_NOFOLLOW = 0x1;
    enum AT_SYMLINK_FOLLOW   = 0x2;
    enum AT_REMOVEDIR        = 0x4;

    enum AT_FDCWD            = -2;
}
else
{
    static assert(false, "Unsupported platform");
}

/*
int creat(const scope char*, mode_t);
int fcntl(int, int, ...);
int open(const scope char*, int, ...);
int openat(int, const scope char*, int, ...);
*/
version (CRuntime_Glibc)
{
    static if ( __USE_FILE_OFFSET64 )
    {
        int   creat64(const scope char*, mode_t);
        alias creat = creat64;

        int   open64(const scope char*, int, ...);
        alias open = open64;

        int   openat64(int, const scope char*, int, ...);
        alias openat = openat64;
    }
    else
    {
        int   creat(const scope char*, mode_t);
        int   open(const scope char*, int, ...);
        int   openat(int, const scope char*, int, ...);
    }
}
else version (Darwin)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (FreeBSD)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (OpenBSD)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (NetBSD)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (DragonFlyBSD)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (Solaris)
{
    version (D_LP64)
    {
        int creat(const scope char*, mode_t);
        int open(const scope char*, int, ...);
        int openat(int, const scope char*, int, ...);

        static if (__USE_LARGEFILE64)
        {
            alias creat64 = creat;
            alias open64 = open;
            alias openat64 = openat;
        }
    }
    else
    {
        static if (__USE_LARGEFILE64)
        {
            int creat64(const scope char*, mode_t);
            alias creat = creat64;

            int open64(const scope char*, int, ...);
            alias open = open64;

            int openat64(int, const scope char*, int, ...);
            alias openat = openat64;
        }
        else
        {
            int creat(const scope char*, mode_t);
            int open(const scope char*, int, ...);
            int openat(int, const scope char*, int, ...);
        }
    }
}
else version (CRuntime_Bionic)
{
    int   creat(const scope char*, mode_t);
    int   open(const scope char*, int, ...);
    int   openat(int, const scope char*, int, ...);
}
else version (CRuntime_Musl)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (CRuntime_WASI)
{
    int creat(const scope char*, mode_t);
    int open(const scope char*, int, ...);
    int openat(int, const scope char*, int, ...);
}
else version (CRuntime_UClibc)
{
    static if ( __USE_FILE_OFFSET64 )
    {
        int   creat64(const scope char*, mode_t);
        alias creat = creat64;

        int   open64(const scope char*, int, ...);
        alias open = open64;

        int openat64(int, const scope char*, int, ...);
        alias openat = openat64;
    }
    else
    {
        int   creat(const scope char*, mode_t);
        int   open(const scope char*, int, ...);
        int openat(int, const scope char*, int, ...);
    }
}
else
{
    static assert(false, "Unsupported platform");
}

//int creat(const scope char*, mode_t);
int fcntl(int, int, ...);
//int open(const scope char*, int, ...);

// Generic Posix fallocate
int posix_fallocate(int, off_t, off_t);

//
// Advisory Information (ADV)
//
/*
POSIX_FADV_NORMAL
POSIX_FADV_SEQUENTIAL
POSIX_FADV_RANDOM
POSIX_FADV_WILLNEED
POSIX_FADV_DONTNEED
POSIX_FADV_NOREUSE

int posix_fadvise(int, off_t, off_t, int);
*/
