csv- ArrayOfArrays文件:第一个内部数组为空？

Question

下面的代码获取一个上传的csv文件，将其保存在一个数组的数组中，然后我尝试使用Text::CSV_XS从这个数组的数组中创建一个新的csv文件。我知道我可以将上传的文件保存为"move_to"，但这不是我想要的。

这里我的问题是:当我保存csv文件时，这个csv文件的第一行和最后一行都是空的，我不知道为什么。有人能给我解释一下吗？

package MyApp::Controller::Main;
use Mojo::Base 'Mojolicious::Controller';
use Text::CSV_XS qw( csv );
use Encode;
use Cwd;

sub upload {
    my $self = shift;
    return $self->render(text => 'File is too big.', status => 200) if $self->req->is_limit_exceeded;
    return $self->redirect_to('/') unless my $newCsv = $self->req->upload('fileToUpload')->slurp;

    open(my $myFH, '<',\$newCsv) or die $!;
    my @lines = readline($myFH);
    close($myFH);
    my $checkCsv = Text::CSV_XS->new({sep_char => ';', quote_char => '"'});
    my @csvArray = [];
    # my $arrayIndex = 0; #temp
    foreach my $line (@lines){
        $line = decode('UTF-8', $line);
        $line =~ s/\N{U+FEFF}//; # remove the BOM
        $line =~ s/\s+$//g; # remove \n
        if ($checkCsv->parse($line) and $checkCsv->fields()){
            my @fields = $checkCsv->fields();
            push(@csvArray, \@fields);
        }
    }

    $self->app->log->debug($self->dumper(@csvArray));

    my $size = $self->param('fileToUpload')->size;
    my $name = $self->param('fileToUpload')->filename;
    csv (in => \@csvArray, sep_char=> ";", out => getcwd.'/lib/MyApp/files/'.$name);
    # $self->app->log->debug(getcwd);
    my $delay = 3;
    $self->stash(delay => $delay, message => "Thanks for uploading $size byte file $name.<br>
        You will be redirected in $delay seconds");
    $self->render('main/upload');
}

提前谢谢你。

Answer 1

替换

my @csvArray = [];   # Create empty array @cvsArray, then add a ref to an empty array to it.

使用

my @csvArray = ();   # Create empty array @cvsArray, then empty it.

更好的是，只需使用以下代码：

my @csvArray;        # Create empty array @cvsArray.