use Fcntl;
    use Fcntl qw(:DEFAULT :flock);
#define symbols get translated; you must still correctly pack up your own arguments
to pass as args for locking functions, etc.
You can request that the flock() constants 
(LOCK_SH, 
LOCK_EX, 
LOCK_NB and 
LOCK_UN) be provided by using the tag
 :flock. See the Exporter manpage.
You can request that the old constants 
(FAPPEND, 
FASYNC, 
FCREAT, 
FDEFER, 
FEXCL, 
FNDELAY, 
FNONBLOCK, 
FSYNC, 
FTRUNC) be provided for compatibility reasons by using the tag
 :Fcompat. For new applications the newer versions of these constants are suggested 
(O_APPEND, 
O_ASYNC, 
O_CREAT, 
O_DEFER, 
O_EXCL, 
O_NDELAY, 
O_NONBLOCK, 
O_SYNC, 
O_TRUNC).
Please refer to your native fcntl() and open()
documentation to see what constants are implemented in your system.