Fcntl - load the C Fcntl.h defines

- NAME
- SYNOPSIS
- DESCRIPTION
- NOTE
- EXPORTED SYMBOLS

# 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 fcntl.h file. Unlike the old mechanism of requiring a translated fcntl.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 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).

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)` documentation to see what constants are implemented in your system.

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

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

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

Fcntl - load the C Fcntl.h defines