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 (int)F_GETFD (int)F_GETFL (int)F_GETLK (int)F_GETOWN (int)F_RDLCK (int)F_SETFL (int)F_SETLK (int)F_SETLKW (int)F_SETOWN (int)F_UNLCK (int)F_WRLCK (int)O_APPEND (int)O_ASYNC (int)O_CREAT (int)O_EXCL (int)O_NDELAY (int)O_NOCTTY (int)O_NONBLOCK (int)O_RDONLY (int)O_RDWR (int)O_SYNC (int)O_TRUNC (int)O_WRONLY (int)S_IRGRP (int)S_IROTH (int)S_IRUSR (int)S_IRWXG (int)S_IRWXO (int)S_IRWXU (int)S_IWGRP (int)S_IWOTH (int)S_IWUSR (int)S_IXGRP (int)S_IXOTH (int)S_IXUSR (int)