我正在关注网上找到的关于上传图片的教程。由于我是新手,因此需要您的帮助才能更好地理解编码人员的想法。
您会看到,有一个数组,其中包含分配给可能的上传错误的键和值。我想知道这些错误将如何触发,因为我在代码的其他地方找不到关系。
我难以理解的是:这些键 1,2,3,... 是描述 PHP 上传错误的标准值还是仅仅是数字?
第二个问题,是否有另一种方法可以根据这种情况在不使用 PHP 函数并避免回显的情况下打印错误消息?
代码如下:
<?php
// filename: upload.processor.php
// first let's set some variables
// make a note of the current working directory, relative to root.
$directory_self = str_replace(basename($_SERVER['PHP_SELF']), '', $_SERVER['PHP_SELF']);
// make a note of the directory that will recieve the uploaded files
$uploadsDirectory = $_SERVER['DOCUMENT_ROOT'] . $directory_self . 'uploaded_files/';
// make a note of the location of the upload form in case we need it
$uploadForm = 'http://' . $_SERVER['HTTP_HOST'] . $directory_self . 'upload.form.php';
// make a note of the location of the success page
$uploadSuccess = 'http://' . $_SERVER['HTTP_HOST'] . $directory_self . 'upload.success.php';
// name of the fieldname used for the file in the HTML form
$fieldname = 'file';
// Now let's deal with the upload
// possible PHP upload errors
$errors = array(1 => 'php.ini max file size exceeded',
2 => 'html form max file size exceeded',
3 => 'file upload was only partial',
4 => 'no file was attached');
// check the upload form was actually submitted else print form
isset($_POST['submit'])
or error('the upload form is neaded', $uploadForm);
// check for standard uploading errors
($_FILES[$fieldname]['error'] == 0)
or error($errors[$_FILES[$fieldname]['error']], $uploadForm);
// check that the file we are working on really was an HTTP upload
@is_uploaded_file($_FILES[$fieldname]['tmp_name'])
or error('not an HTTP upload', $uploadForm);
// validation... since this is an image upload script we
// should run a check to make sure the upload is an image
@getimagesize($_FILES[$fieldname]['tmp_name'])
or error('only image uploads are allowed', $uploadForm);
// make a unique filename for the uploaded file and check it is
// not taken... if it is keep trying until we find a vacant one
$now = time();
while(file_exists($uploadFilename = $uploadsDirectory.$now.'-'.$_FILES[$fieldname]['name']))
{
$now++;
}
// now let's move the file to its final and allocate it with the new filename
@move_uploaded_file($_FILES[$fieldname]['tmp_name'], $uploadFilename)
or error('receiving directory insuffiecient permission', $uploadForm);
// If you got this far, everything has worked and the file has been successfully saved.
// We are now going to redirect the client to the success page.
header('Location: ' . $uploadSuccess);
// make an error handler which will be used if the upload fails
function error($error, $location, $seconds = 5)
{
header("Refresh: $seconds; URL=\"$location\"");
echo '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"'."\n".
'"http://www.w3.org/TR/html4/strict.dtd">'."\n\n".
'<html lang="en">'."\n".
' <head>'."\n".
' <meta http-equiv="content-type" content="text/html; charset=iso-8859-1">'."\n\n".
' <link rel="stylesheet" type="text/css" href="stylesheet.css">'."\n\n".
' <title>Upload error</title>'."\n\n".
' </head>'."\n\n".
' <body>'."\n\n".
' <div id="Upload">'."\n\n".
' <h1>Upload failure</h1>'."\n\n".
' <p>An error has occured: '."\n\n".
' <span class="red">' . $error . '...</span>'."\n\n".
' The upload form is reloading</p>'."\n\n".
' </div>'."\n\n".
'</html>';
exit;
} // end error handler
?>