JezK
Edit File: 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;