Current File : //usr/lib64/perl5/vendor_perl/File/FcntlLock/Pure.pm
# -*- cperl -*-
#
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
#
# Copyright (C) 2002-2014 Jens Thoms Toerring <jt@toerring.de>
# Package for file locking with fcntl(2) in which the binary layout of
# the C flock struct has been determined via a C program on installation
# and appropriate Perl code been appended to the package.
package File::FcntlLock::Pure;
use 5.006;
use strict;
use warnings;
use base qw( File::FcntlLock::Core );
our $VERSION = File::FcntlLock::Core->VERSION;
our @EXPORT = @File::FcntlLock::Core::EXPORT;
###########################################################
# Function for doing the actual fcntl() call: assembles the binary
# structure that must be passed to fcntl() from the File::FcntlLock
# object we get passed, calls it and then modifies the File::FcntlLock
# with the data from the flock structure
sub lock {
my ( $self, $fh, $action ) = @_;
my $buf = $self->pack_flock( );
my $ret = fcntl( $fh, $action, $buf );
if ( $ret ) {
$self->unpack_flock( $buf );
$self->{ errno } = $self->{ error } = undef;
} else {
$self->get_error( $self->{ errno } = $! + 0 );
}
return $ret;
}
###########################################################
# Method created automatically while running 'perl Makefile.PL'
# (based on the the C 'struct flock' in <fcntl.h>) for packing
# the data from the 'flock_struct' into a binary blob to be
# passed to fcntl().
sub pack_flock {
my $self = shift;
return pack( 'ssx4qqlx4',
$self->{ l_type },
$self->{ l_whence },
$self->{ l_start },
$self->{ l_len },
$self->{ l_pid } );
}
###########################################################
# Method created automatically while running 'perl Makefile.PL'
# (based on the the C 'struct flock' in <fcntl.h>) for unpacking
# the binary blob received from a call of fcntl() into the
# 'flock_struct'.
sub unpack_flock {
my ( $self, $data ) = @_;
( $self->{ l_type },
$self->{ l_whence },
$self->{ l_start },
$self->{ l_len },
$self->{ l_pid } ) = unpack( 'ssx4qqlx4', $data );
}
1;
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