Fcntl(l)     Perl Programmers Reference Guide    Fcntl(l)



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 cor-
       rectly 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 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).

       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(l), open(n), fseek(k),
       lseek(k) (equal to Perl's seek() and sysseek(), respec-
       tively), and chmod(d) documentation to see what constants
       are implemented in your system.

       See perlopentut to learn about the uses of the O_* con-
       stants with sysopen().

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

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



perl v5.6.1                 2001-03-03               Fcntl(l)