redhat man page for fcntl

Fcntl(3pm)						 Perl Programmers Reference Guide						Fcntl(3pm)

NAME
       Fcntl - load the C Fcntl.h defines

SYNOPSIS
	   use Fcntl;
	   use Fcntl qw(:DEFAULT :flock);

DESCRIPTION
       This module is just a translation of the C fnctl.h file.  Unlike the old mechanism of requiring a translated fnctl.ph file, this uses the
       h2xs program (see the Perl source distribution) and your native C compiler.  This means that it has a far more likely chance of getting the
       numbers right.

NOTE
       Only "#define" symbols get translated; you must still correctly pack up your own arguments to pass as args for locking functions, etc.

EXPORTED SYMBOLS
       By default your system's F_* and O_* constants (eg, F_DUPFD and O_CREAT) and the FD_CLOEXEC constant are exported into your namespace.

       You can request that the flock() constants (LOCK_SH, LOCK_EX, LOCK_NB and LOCK_UN) be provided by using the tag ":flock".  See Exporter.

       You can request that the old constants (FAPPEND, FASYNC, FCREAT, FDEFER, FEXCL, FNDELAY, FNONBLOCK, FSYNC, FTRUNC) be provided for compati-
       bility 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).

       For ease of use also the SEEK_* constants (for seek() and sysseek(), e.g. SEEK_END) and the S_I* constants (for chmod() and stat()) are
       available for import.  They can be imported either separately or using the tags ":seek" and ":mode".

       Please refer to your native fcntl(2), open(2), fseek(3), lseek(2) (equal to Perl's seek() and sysseek(), respectively), and chmod(2) docu-
       mentation to see what constants are implemented in your system.

       See perlopentut to learn about the uses of the O_* constants with sysopen().

       See "seek" in perlfunc and "sysseek" in perlfunc about the SEEK_* constants.

       See "stat" in perlfunc about the S_I* constants.

perl v5.8.0							    2002-06-01								Fcntl(3pm)