FILE: C:\Program Files (x86)\Plesk\perl\lib\Fcntl.pm
--
package Fcntl;
=head1 NAME
Fcntl - various flag constants and helper functions from C's fcntl.h
=head1 SYNOPSIS
use Fcntl;
use Fcntl qw(:DEFAULT :flock);
use Fcntl qw(F_GETFD F_SETFD FD_CLOEXEC);
=head1 DESCRIPTION
This module provides flags and helper functions for use with L
(S_*), L (F_*), L (LOCK_*), L
(SEEK_*), L (S_*), L (O_*), and
L (SEEK_*). They correspond to the C macros defined in
F.
Not all symbols are available on all systems. Except where noted otherwise,
the constants and functions provided by this module will throw a runtime
exception if the corresponding C macro is not available. Consult your system
documentation to see the full description of each symbol and whether it is
available on your platform: L, L, L,
L, L, L.
(In particular, some of the F_* symbols are highly non-portable because they
only exist on a single platform or require system-specific C data structures to
be passed as the third argument to C, which can't be portably
constructed in pure Perl.)
=head1 EXPORTED SYMBOLS
=head2 Default exports and export tags
The full list of default exports can be found below in L.
In addition, the following export tags are available (see L for more
information on export tags):
=over
=item C<:DEFAULT>
Equivalent to the list of default export symbols (see L).
=item C<:flock>
Equivalent to all LOCK_* symbols listed below.
=item C<:mode>
Equivalent to all S_* symbols listed below.
=item C<:seek>
Equivalent to all SEEK_* symbols listed below.
=item C<:Fcompat>
Equivalent to C. These only exist for compatibility with old
code (if your platform defines them at all) and should not be used in new code.
=back
=head2 Symbols for use with C
=over
=item C
File storage manipulation.
=item C
File storage manipulation.
=item C
Duplicate a file descriptor to the number specified in the third argument to
C (if it refers to an open file, it is automatically closed first).
=item C
Duplicate a file descriptor to the lowest unused number greater than or equal
to the third argument of C.
=item C
File storage manipulation.
=item C
File storage manipulation.
=item C
Synchronize file data to disk.
=item C
Synchronize file data to disk.
=item C
Return (as a number) the set of file descriptor flags, in which the following
bits may be set:
=over
=item C
During a successful C call, the file descriptor will be closed
automatically.
=back
=item C
Return (as a number) the set of file description status flags (O_*) as set by
C and C. To determine the file access mode, perform a bitwise AND
with L> and see whether the result is equal to C,
C, or C.
=item C
Indicate the type of lease associated with the filehandle (if any) by returning
one of the following flags:
=over
=item C
A read lease.
=item C
A write lease.
=item C
No lease.
=back
=item C
Test for the existence of record locks on the file.
=item C
Test for the existence of record locks on the file.
=item C
Return the ID of the process (as a positive number) or group (as a negative
number) that is currently receiving signals for events on the file descriptor.
=item C
Return the capacity of the pipe associated with the filehandle.
=item C
Return the number of the signal sent when input or output becomes possible on
the filehandle. A return value of C<0> means C.
=item C
File and directory change notification with signals.
=over
=item C
=item C
=item C
=item C
=item C
=item C
=item C
=back
Z<>
=item C
Set the file descriptor flags. See L> for the list of available
flags.
=item C
Set the file description status flags (O_*). Only some flags can be changed
this way.
=item C
Set a file lease as specified by the third C argument, which must be one
of the following:
=over
=item C
Set a read lease.
=item C
Set a write lease.
=item C
Remove a lease.
=back
=item C
Acquire a record lock.
=item C
Acquire a record lock.
=item C
Acquire a record lock and wait for conflicting locks to be released.
=item C
Acquire a record lock and wait for conflicting locks to be released.
=item C
Set the ID of the process (as a positive number) or group (as a negative
number) that will receive signals for events on the file descriptor.
=item C
Set the capacity of the pipe associated with the filehandle. Return the actual
capacity reserved for the pipe, which may be higher than requested.
=item C
Set the number of the signal sent when input or output becomes possible on the
filehandle. An argument of C<0> means C.
=item C
Set share reservation.
=item C
Remove share reservation.
=item C
=item C
=item C
=item C
=item C
=item C
=item C
=item C
=item C
=item C
=item C
=back
=head2 Symbols for use with C
=over
=item C
Request an exclusive lock.
=item C
Request a mandatory lock.
=item C
Make lock request non-blocking (can be combined with other LOCK_* flags using bitwise OR).
=item C
With C: Allow concurrent reads.
=item C
With C: Allow concurrent reads and writes.
=item C
Request a shared lock.
=item C
Release a held lock.
=item C
With C: Allow concurrent writes.
=back
=head2 Symbols for use with C
=over
=item C
Bit mask for extracting the file access mode (read-only, write-only, or
read/write) from the other flags. This is mainly useful in combination with
L>.
=item C
(Mac OS) Open alias file (instead of the file that the alias refers to).
=item C
(NetBSD) Use alternative I/O semantics.
=item C
Open the file in append mode. Writes always go to the end of the file.
=item C
Enable signal-based I/O. When the file becomes readable or writable, a signal
is sent.
=item C
(Windows) Open the file in binary mode.
=item C
If the file to be opened does not exist yet, create it.
=item C
(AIX) Changes to the file are kept in memory and not written to disk until the
program performs an explicit L<< C<< $fh->sync() >>|IO::Handle/$io->sync >>.
=item C
Perform direct I/O to/from user-space buffers; avoid caching at the OS level.
=item C
Fail if the filename to be opened does not refer to a directory.
=item C
Synchronize file data immediately, like calling L after each
write.
=item C
(Mac OS) Open the file for event notifications, not reading or writing.
=item C
If the file already exists, fail and set C<$!> to L|Errno> (this only
makes sense in combination with C).
=item C
When the file is opened, atomically obtain an exclusive lock.
=item C
(Hurd) If the file to be opened is the controlling terminal for this process,
don't recognize it as such. Operations on this filehandle won't trigger job
control signals.
=item C
On 32-bit platforms, allow opening files whose size exceeds 2 GiB
(2,147,483,647 bytes).
=item C
Compatibility symbol. Use C instead.
=item C
Don't update the access time of the file when reading from it.
=item C
If the process does not have a controlling terminal and the file to be opened
is a terminal device, don't make it the controlling terminal of the process.
=item C
If the final component of the filename is a symbolic link, fail and set C<$!>
to L|Errno>.
=item C
(Windows) Don't let child processes inherit the opened file descriptor.
=item C
(Hurd) If the file to be opened is a symbolic link, don't follow it; open the
link itself.
=item C
Open the file in non-blocking mode. Neither the open itself nor any read/write
operations on the filehandle will block. (This is mainly useful for pipes and
sockets. It has no effect on regular files.)
=item C
If the file to be opened is a pipe, then don't raise C for write
operations when the read end of the pipe is closed; make the write fail with
C instead.
=item C
(Hurd) If the file to be opened is specially translated, don't invoke the
translator; open the bare file itself.
=item C
(Windows) Indicate that the program intends to access the file contents
randomly (without a predictable pattern). This is an optimization hint for the
file cache (but may cause excessive memory use on large files).
=item C
(Windows) Same as C.
=item C
Open the file for reading (only).
=item C
Open the file for reading and writing.
=item C
(Mac OS) Open the resource fork of the file.
=item C
Extend the effects of C and C to read operations. In
particular, reading from a filehandle opened with C will wait
until the access time of the file has been modified on disk.
=item C
(Windows) Indicate that the program intends to access the file contents
sequentially. This is an optimization hint for the file cache.
=item C
When the file is opened, atomically obtain a shared lock.
=item C
If the file to be opened is a symbolic link, don't follow it; open the link
itself.
=item C
Synchronize file data and metadata immediately, like calling L after
each write.
=item C
(Windows) Delete the file when its last open file descriptor is closed.
=item C
(Windows) Open the file in text mode.
=item C
Create an unnamed temporary file. The filename argument specifies the directory
the unnamed file should be placed in.
=item C
If the file already exists, truncate its contents to length 0.
=item C
If the file to be opened is a terminal that is not already open in any process,
initialize its L> parameters.
=item C
Open the file for writing (only).
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=item C
Compatibility symbol. Use C instead.
=back
=head2 Symbols for use with C and C
=over
=item C
File offsets are relative to the current position in the file.
=item C
File offsets are relative to the end of the file (i.e. mostly negative).
=item C
File offsets are absolute (i.e. relative to the beginning of the file).
=back
=head2 Symbols for use with C and C
=over
=item C
Enforce mandatory file locks. (This symbol typically shares its value with
C.)
=item C
Compatibility symbol. Use C instead.
=item C
File type: Block device.
=item C
File type: Character device.
=item C
File type: Directory.
=item C
File type: Fifo/pipe.
=item C
File type: Symbolic link.
=item C
Bit mask for extracting the file type bits. This symbol can also be used as a
function: C acts like C<$mode & S_IFMT>. The result will be
equal to one of the other S_IF* constants.
=item C<_S_IFMT>
Bit mask for extracting the file type bits. This symbol is an actual constant
and cannot be used as a function; otherwise it is identical to C.
=item C
File type: Regular file.
=item C
File type: Socket.
=item C
File type: Whiteout file (used to mark the absence/deletion of a file in overlays).
=item C
Function for extracting the permission bits from a file mode.
=item C
Compatibility symbol. Use C instead.
=item C
Permissions: Readable by group.
=item C
Permissions: Readable by others.
=item C
Permissions: Readable by owner.
=item C
Bit mask for extracting group permissions.
=item C
Bit mask for extracting other permissions.
=item C
Bit mask for extracting owner ("user") permissions.
=item C
Convenience function to check for block devices: C is
equivalent to C.
=item C
Convenience function to check for character devices: C is
equivalent to C.
=item C
Convenience function to check for directories: C is
equivalent to C.
=item C
Broken function; do not use. (C should always return false,
anyway.)
=item C
Convenience function to check for fifos: C is
equivalent to C.
=item C
Permissions: Set effective group ID from file (when running executables);
mandatory locking (on non-group-executable files); new files inherit their
group from the directory (on directories).
=item C
Convenience function to check for symbolic links: C is
equivalent to C.
=item C
Convenience function to check for regular files: C is
equivalent to C.
=item C
Convenience function to check for sockets: C is
equivalent to C.
=item C
Compatibility symbol. Use C instead.
=item C
Permissions: Set effective user ID from file (when running executables).
=item C
Permissions: Files in this directory can only be deleted/renamed by their owner
(or the directory's owner), even if other users have write permissions to the
directory ("sticky bit").
=item C
Convenience function to check for whiteout files: C is
equivalent to C.
=item C
Permissions: Writable by group.
=item C
Permissions: Writable by others.
=item C
Compatibility symbol. Use C instead.
=item C
Permissions: Writable by owner.
=item C
Permissions: Executable/searchable by group.
=item C
Permissions: Executable/searchable by others.
=item C
Permissions: Executable/searchable by owner.
=back
=head1 SEE ALSO
L, L,
L, L,
L, L,
L, L