php利用open,fwrite实现导出多种格式的文件（代码）

<?php
/**
 * Created by PhpStorm.
 * User: Jason0727
 * Date: 2018/8/9
 * Time: 14:48
 */header("Content-Type: text/html;charset=utf-8");//定义文件名
 $fileName = "测试文件名_" . date(&#39;YmdHis&#39;);//文件名中间不能有空格//文件名转码，以防乱码
 $fileName = iconv(&#39;UTF-8&#39;,&#39;GBK&#39;,$fileName);///文件后缀
 $ext = ".csv";//$ext = ".txt";//字段间的拼接符号//
 $dot = "|";$dot = ",";//打开文件句柄，记得赋权，否则报错
 $fp = fopen("./files/" . $fileName . $ext,"a") or die("unable to open file!");//是否需要列表名称，0=>不需要 1需要，默认为1
 $is_need_headerList = 1;//检测是否需要
 headerListif($is_need_headerList == 1){    //定义列表名称
    $headerList = [&#39;列表1&#39;,&#39;列表2&#39;,&#39;列表3&#39;];    //初始化写入文件的字符串
    $headerTxt = "";    //列表名称转码
    foreach ($headerList as $v){        
    $headerTxt .= $v. $dot;
    }    
    $headerTxt = rtrim($headerTxt,$dot)."\n";    //将列表名称写入文件句柄
    fwrite($fp, $headerTxt);
}//初始化数组数据$data = [
    [&#39;id&#39;=>&#39;值1&#39;,&#39;name&#39;=>&#39;值2&#39;,&#39;hobby&#39;=>&#39;值3&#39;],
    [&#39;id&#39;=>&#39;值11&#39;,&#39;name&#39;=>&#39;值22&#39;,&#39;hobby&#39;=>&#39;值33&#39;],
    [&#39;id&#39;=>&#39;值111&#39;,&#39;name&#39;=>&#39;值222&#39;,&#39;hobby&#39;=>&#39;值333&#39;]
];
//循环写入数据//初始化数组的总数
$count = count($data);//循环次数
$limit = 0;foreach ($data as $v){    
$limit++;    
$txt = $v[&#39;id&#39;] .$dot . $v[&#39;name&#39;] .$dot .$v[&#39;hobby&#39;];    
if($count != $limit)//避免最后一次换行
        $txt .= $dot .PHP_EOL;
    fwrite($fp,$txt);
}
fclose($fp);

$c = "测试•字符传换•五一快乐!";echo iconv('UTF-8','GBK//IGNORE',$c);//测试字符传换五一快乐!echo iconv('UTF-8','GBK',$c);//Detected an illegal character in input string