PHP编写CSV，出于某种原因输出整个网页

Question

function outputCSV($data) {
    $outstream = fopen("php://output", 'w');
    function __outputCSV(&$vals, $key, $filehandler){
        fputcsv($filehandler, $vals, ',', '"');
    }
    array_walk($data, '__outputCSV', $outstream);
    fclose($outstream);
}


function someFunctionInTheBigPHPFile() {
    header("Content-type: text/csv");
    header("Content-Disposition: attachment; filename=file.csv");
    header("Pragma: no-cache");
    header("Expires: 0");

    $mydata = array(
    array('data11', 'data12', 'data13'),
    array('data21', 'data22', 'data23'),
    array('data31', 'data32', 'data23'));

    outputCSV($mydata);
    exit;
}

The output CSV does contain the data array. The problem is, this array is displayed along with the rest of the webpage, that is everything before this function is called and everything that comes after it, despite these two functions being the only ones that deal with any fopen and writing to files.

How can I stop the rest of the webpage from interfering? I only want the data array in the CSV..

EDIT: I managed to chop off everything succeeding my array by adding exit;, but I still have the problem of the entire website being displayed before the array.

Answer 1

At the beginning of the PHP file, check straight away if you want to print your CSV (this is probably passed through $_POST or $_GET). If so, run it straight through the function and end that function with an exit;.

This prevents anything from happening before or after the CSV is created. For some reason all code on the page is included in the new file, even if the file stream was opened and closed at times independant of when the page's content was computed.

And this effectively leaves you with only what you wanted, not the rubbish before or after it.