$myfile = fopen("newfile.txt", "w") or die("Unable to open file!");
$txt = "Bill Gates\n";
fwrite($myfile, $txt);
$txt = "Steve Jobs\n";
fwrite($myfile, $txt);
fclose($myfile);

? >
this is an example on w3school
http://www.w3school.com.cn/ph...

post the code that downloaded the csv file before. The principle is the same

        set_time_limit(0);
        ini_set('memory_limit', '1024M');
        $fileName = 'WinterStudentCount-'.date('YmdHis', time());
        header('Content-Type: application/vnd.ms-execl');
        header('Content-Disposition: attachment;filename="' . $fileName . '.csv"');
        header('Cache-Control: max-age=0');
        //php
        //
        $fp = fopen('php://output', 'a');
        // 
        $info = ['','','','','',''];
        foreach ($info as $k => $v) {
            $title[] = iconv('UTF-8', 'gbk//IGNORE', $v);
        }
        //
        $data = WinterStudentDataForm::find()->where($map);
        $datainfo = $data->select(['school','year','number','enroll_number'])->asarray()->all();
        for ($i=0; $i < count($datainfo); $iPP) { 
            $datainfo[$i]['rate'] = $datainfo[$i]['enroll_number'].' \ '.$datainfo[$i]['number'];
        }
        $year = isset($map['year'])?$map['year']:'0';
        $number_sum = $data->sum('number');
        $enroll_number_sum = $data->sum('enroll_number');
        $info_count = ['',iconv('UTF-8', 'gbk//IGNORE', ''),$year,$number_sum,$enroll_number_sum,$enroll_number_sum.' \ '.$number_sum];
        if($datainfo) {
            //
            $i = 1;
            fputcsv($fp, $title);
            foreach($datainfo as $key=> $item) {
                //
                $order = $iPP;
                foreach($item as $k => $v){
                    $row['order'] = $order;
                    $row[$k] = iconv('UTF-8', 'gbk//IGNORE', $v);
                }
                fputcsv($fp, $row);
            }
            fputcsv($fp, $info_count);
        }

think of it this way: write the array to txt first, because the array cannot be written directly, and the data can be written after processing, such as json. The second part calls the download API to download this file to the local

php reads csv file data and outputs it, changes CSV into corresponding TXT, and outputs

$file = fopen("log.txt", "r");
        $user=array();
        $i=0;
//
        while(! feof($file))
        {
            $user[$i]= fgets($file);//fgets()
            $iPP;
        }
        fclose($file);
        $user=array_filter($user);
        print_r($user);

download

class UserExcelController extends Controller
{
    /**
     * 
     * @param $dataArr  ;
     * @param $fieldArr $dataArrkeyvalue ;
     * @param $tname excel;
     * @author qingfeng.guo
     * 2016-06-21
     */
    function exportExcel($dataArr,$fieldArr,$tname="")
    {
        if(!is_array($fieldArr) || empty($fieldArr))
            die("");

        if(!empty($dataArr) && count($dataArr) > 10000)
            die("10000");

        $thead = ''; //
        $tbody = ''; //
        $ttail = ''; //
        $clos = count($fieldArr); //
        //
        $thead .= '<tr>';
        foreach($fieldArr as $k => $v)
        {
            $thead .= '<td style="color:-sharpfff;background-color:green;">'.$v.'</td>';
        }
        $thead .= '</tr>';
        //
        $ttail = '<tr><td colspan="'.$clos.'"> :'.$tname.' , :'.date("Y-m-d H:i:s").' </td></tr>';

        //
        $datas = array();
        foreach($dataArr as $k => $v)
        {
            $v['created_at'] = date('Y-m-d H:i:s',$v['created_at']);
            $fieldFormat = $fieldArr; //
            if(!empty($v) && is_array($v))
            {
                foreach($v as $k2 => $v2)
                {
        //key
                    if(array_key_exists($k2, $fieldArr))
                    {
                        $fieldFormat[$k2] = $v2;
                    }
                }
            }
            $datas[] = $fieldFormat;
        }
        //
        foreach ($datas as $k => $v)
        {
            $tbody .= '<tr>';
            foreach($v as $k2 => $v2)
            {
                if(!is_numeric($v2))
                {
                    $tbody .= '<td style="vnd.ms-excel.numberformat:@">'.$v2.'</td>';
                }else{
                    $tbody .= '<td>'.$v2.'</td>';
                }
            }
            $tbody .= '</tr>';
        }

        $content = $thead.$tbody.$ttail;
        header("content-type:application/vnd.ms-excel; charset=utf8");
        header("Content-Disposition:attachment;filename={$tname}".time().".xls");
        echo "<table align='center' border=1 bgcolor='F8F7ED'>";
        if(mb_detect_encoding($content) != 'UTF-8')
        {
            echo iconv('UTF-8',"GB2312",$content);
        }else{
            echo $content;
        }
        echo "</table>";
    }



    //
    public function userExcel(Request $request){
        $list = User::join('users as u','u.id','=','users.pid')
            ->select('users.id','users.nickname','u.nickname as u_nickname','users.phone','u.phone as u_phone','users.email','users.created_at')
            ->paginate(10)->toArray();
        $list =$list['data'];
        $fieldArr = array(
            'id' => 'id',
            'nickname' => '',
            'u_nickname' => '',
            'phone' =>'',
            'u_phone'=>'',
            'email'=>'',
            'created_at'=>'',
        );
        $this->exportExcel($list, $fieldArr,'');
    }
}