The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
F_DUPFD
    (integer)
   F_GETFD
    (integer)
   F_GETFL
    (integer)
   F_GETLK
    (integer)
   F_GETOWN
    (integer)
   F_RDLCK
    (integer)
   F_SETFL
    (integer)
   F_SETLK
    (integer)
   F_SETLKW
    (integer)
   F_SETOWN
    (integer)
   F_UNLCK
    (integer)
   F_WRLCK
    (integer)
   O_APPEND
    (integer)
   O_ASYNC
    (integer)
   O_CREAT
    (integer)
   O_EXCL
    (integer)
   O_NDELAY
    (integer)
   O_NOCTTY
    (integer)
   O_NONBLOCK
    (integer)
   O_RDONLY
    (integer)
   O_RDWR
    (integer)
   O_SYNC
    (integer)
   O_TRUNC
    (integer)
   O_WRONLY
    (integer)
   S_IRGRP
    (integer)
   S_IROTH
    (integer)
   S_IRUSR
    (integer)
   S_IRWXG
    (integer)
   S_IRWXO
    (integer)
   S_IRWXU
    (integer)
   S_IWGRP
    (integer)
   S_IWOTH
    (integer)
   S_IWUSR
    (integer)
   S_IXGRP
    (integer)
   S_IXOTH
    (integer)
   S_IXUSR
    (integer)