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What are the functions in php to implement the upload function?

藏色散人Original: 2021-12-30 09:56:483870browse

The functions used by php to implement the upload function are: 1. move_uploaded_file function; 2. getimagesize function; 3. extend function; 4. explode function; 5. count function, etc.

#The operating environment of this article: Windows 7 system, PHP version 7.1, Dell G3 computer.

What are the functions in php to implement the upload function?

Detailed code example for php to implement file upload function

We cannot do without uploading filesmove_uploaded_fileFunction This function checks and ensures that it is specified by file The file is a legal uploaded file (that is, uploaded through the http post upload mechanism of the php tutorial). If the file is legal, it is moved to the file specified by newloc.

If file is not a legal uploaded file, no operation will occur and move_uploaded_file() will return false.

If file is a legal uploaded file but cannot be moved for some reason, no action will occur and move_uploaded_file() will return false and a warning will be issued.

Let’s first look at the upload form settings

<html>
<head>
<title>a simple file upload form</title>
</head>
<body>
<form enctype="multipart/form-data"
   action="<?print $_server[&#39;php_self&#39;]?>" method="post">
<p>
<input type="hidden" name="max_file_size" value="102400" />
<input type="file" name="fupload" /><br/>
<input type="submit" value="upload!" />
</p>
</form>
</body>
</html>

In this way, the maximum upload file we set up cannot exceed 102400 bytes

To achieve file upload in php It’s very simple. The following code

if ( $_files[&#39;fupload&#39;][&#39;type&#39;] == "image/gif" ) {
         $source = $_files[&#39;fupload&#39;][&#39;tmp_name&#39;];
         $target = "upload/".$_files[&#39;fupload&#39;][&#39;name&#39;];
         move_uploaded_file( $source, $target );// or die ("couldn&#39;t copy");
         $size = getimagesize( $target );
         $imgstr = "<p><img width="$size[0]" height="$size[1]" ";
         $imgstr .= "src="$target" alt="uploaded image" /></p>";
         print $imgstr;
     }

That’s it. Let’s summarize the examples

php

<html>
<form enctype="multipart/form-data" action="" method="post">
<input type="hidden" name="max_file_size" value="6000000" /> <!--设置允许提交表单的最大字节数-->
文件上传: <input name="file" type="file" />
<input type="submit" value="上传"/>
</form>
</html>

<?
//处理程序
function extend($file_name) //定义获取文件的扩展名函数
{$extend =explode("." , $file_name);
$va=count($extend)-1;
return strtolower($extend[$va]);}
$dirname="../";//是否启用上一层路径,格式为:$dirname="../";或$dirname="http://www.3ppt.com/";等等与$dir组合使用,注意不要溢出根路径
$dir=&#39;upload/aa/bb&#39;;//设定上传目录,与上面的$dirname组合
$file=$_files[&#39;file&#39;];//从文件域表单获取文件
$filename=$file[&#39;name&#39;] ;//获取文件全名
$c_filesize=$file[&#39;size&#39;] ;//获取本地的文件大小
$extendname=extend($filename);//获取文件扩展名
if($c_filesize>200000000000)die("文件太大");//限制上传文件大小, 单位字节
//if($extendname!="jpg")die("只允许上传jpg格式的图片");//限制上传文件格式,去掉语句开头的两斜杠生效
if(!file_exists($dir));//检查目录文件夹是否存在,不存在则建立新文件夹
{
$v=split (&#39;[/.-]&#39;, $dir);
for ( $i=0 ; $i <count($v) ; $i++)
{$dirname=$dirname.$v[$i];
if(!file_exists($dirname))mkdir($dirname);
$dirname=$dirname."/";}
} //目录创建完毕
?>

<?
$dest=$dirname.date("ymdhis", time()).rand(100000,999999).".".$extendname; //设置文件名为日期加上从100000到999999的随机数和扩展名
if(file_exists($dest))die("该文件已经存在");
if(move_uploaded_file($file[&#39;tmp_name&#39;],$dest)) //调用文件上传函数
{$s_filesize=filesize($dest);//获取服务器端的文件大小
echo "文件上传成功,<a href=".$dest.">查看文件地址</a>";
echo "<br>本地文件名:".$filename;
echo "<br>远端文件名:".$dest;
echo "<br>大 小:".ceil($s_filesize/1024)." kb";
echo "<br>扩展名:".$extendname;
echo "<br>大 小:".$c_filesize." byte";}
else
{echo "还未进行文件上传";}
?>

summarizes the error codes of file upload

upload_err_ok No error.

upload_err_ini_size The uploaded file exceeds the highest value present in the file specified.

upload_err_form_size The uploaded file exceeds the maximum value specified by the max_file_size hidden component.

The file upload of upload_err_partial was canceled and only part of the file was uploaded.

upload_err_nofile No file was uploaded.

Recommended learning: "PHP Video Tutorial"

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