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lib/Async/Simple/Task/ForkTmpFile.pm  view on Meta::CPAN

=cut

=head2 tmp_dir

    Path, that used for store tomporary files.
    This path must be writable.
    It can be empty; in this case ( File::Spec->tmpdir() || $ENV{TEMP} ) will be used

    By default:
    During taint -T mode always writes files to current directory ( path = '' )
    Windows outside taint -T mode writes files by default to C:\TEMP or C:\TMP
    Unix    outside taint -T mode writes files by default to /var/tmp/

=cut

has tmp_dir => (
    is       => 'ro',
    isa      => 'Str',
    lazy     => 1,
    builder  => 'make_tmp_dir',
);

sub make_tmp_dir {
    my ( $self ) = @_;

    my $tmp_dir = File::Spec->tmpdir() || '';

    # For WIN taint mode calculated path starts with '\'. Remove it and stay at current(empty) dir
    $tmp_dir = '' if $tmp_dir =~ /^\\$/;

    # TEMP = C:\Users\XXXXXX~1\AppData\Local\Temp
    $tmp_dir ||= $ENV{TEMP} // '';

    # Untaint ENV: fallback, if File::Spec->tmpdir failed
    return [ $tmp_dir =~ /^(.+)$/ ]->[0];
};


=head2 BUILD

internal. Some tricks here:)

    1. Master process called $task->new with fork() inside
    2. After forking done we have two processes:

lib/Async/Simple/Task/ForkTmpFile.pm  view on Meta::CPAN

    	$parent_reader_fname = File::Spec->catfile( $self->tmp_dir, '_pr_tmp_' . $randname->() );

  	next if -f $parent_writer_fname || -f $parent_reader_fname;
	last;
    };

    die 'Can`t obtain unique fname'  if -f $parent_writer_fname || -f $parent_reader_fname;

    my $pid = fork() // die "fork() failed: $!";

    # With taint mode we use current directory as temp,
    # Otherwise - default writable temp directory from File::Spec->tmpdir();

    # child
    unless ( $pid ) {
        $self->writer( $parent_reader_fname );
        $self->reader( $parent_writer_fname );

        # Important!
        # Just after that we trap into BUILD
        # with the infinitive loop for child process (pid=0)