PHP函数下载和覆盖预览下载文件

Question

I am using the following code to download an archived csv file and uncompress it:

$url="http://www.some.zip";
$target = 'data-' . md5(microtime()) . '.zip';

function download($src, $dst) {
        $f = fopen($src, 'rb');
        $o = fopen($dst, 'wb');
        while (!feof($f)) {
            if (fwrite($o, fread($f, 2048)) === FALSE) {
                   return 1;
            }
        }
        fclose($f);
        fclose($o);
        return 0;
}

download($url,$target);

if ( file_exists($target) ){
    echo "Download Successuful <br />";
    $arc = new ZipArchive;
    if (true !== $arc->open($target)) {
        echo "Unzipping Failed <br />";
    }else {
        file_put_contents($out, $arc->getFromIndex(0));
        echo "Unzipping Successuful <br />";
        fclose($handle);
    }
}else {
     echo "Download Failed <br />";
}

However, on a second run, it does't do anything and I would like to overwrite the initial file with the newer file. (the CSV File)

How should I do that? The solution should take about the same time as the first download!

Answer 1

The easiest solution would be to first check if the file exists, then remove it.

function download($src, $dst) {
    if(file_exists($dst)) unlink($dst);
    $f = fopen($src, 'rb');
    $o = fopen($dst, 'wb');
    while (!feof($f)) {
        if (fwrite($o, fread($f, 2048)) === FALSE) {
               return 1;
        }
    }
    fclose($f);
    fclose($o);
    return 0;

}