PHP如何限制jpg，gif，png等文件類型條件？

Question

我想問一下如何限制PHP圖像上傳的文件類型？ 我想將其限制為png，jpg和gif。 很抱歉這個菜鳥問題。

我嘗試過的是在條件中添加“ OR”。 但是，當我上傳jpg，gif或png時，為什么不起作用呢？

<?php 

//limit file type condition
if(!($_FILES["photo"]["type"] == "image/png") 
|| !($_FILES["photo"]["type"] == "image/jpg") 
|| !($_FILES["photo"]["type"] == "image/gif")){

echo "You may only upload png, jpg or gif.<br>";
$ok=0;
} 

?> 

Answer 1

您可以通過使用in_array()使其變得更短，更易讀：

$allowed_extensions = array( "image/png", "image/jpg", "image/gif" );

if ( !in_array( $_FILES[ "photo" ][ "type" ], $allowed_extensions ) ){
  echo "You may only upload png, jpg or gif.<br>";
  $ok = 0;
}

Answer 2

像這樣做

$config['upload_path'] = '';
$config['allowed_types'] = 'gif|jpg|png';       //pic type
$config['max_size'] = '100';
$config['max_width']  = '1024';
$config['max_height']  = '768';
$this->load->library('upload', $config);
$this->upload->initialize($config);

if ( ! $this->upload->do_upload())
{
   $error = array('error' => $this->upload->display_errors()); //you will get error statement in $error
}
else
{....
}