is_uploaded_file() 函数检查文件是否是通过 HTTP POST 上传的。如果文件是通过 HTTP POST 上传的，则该函数返回 TRUE。失败时返回 FALSE。
语法
is_uploaded_file(file_path)
参数
file_path -指定要检查的文件。
返回
如果文件是通过 HTTP POST 上传的，is_uploaded_file() 函数将返回 TRUE。失败时返回 FALSE。
假设我们正在上传包含以下内容的文件“new.txt”。
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This is demo text!
示例
<?php
// checking for file is uploaded via HTTP POST
if (is_uploaded_file($_FILES['userfile'][‘new.txt'])) {
echo "File ". $_FILES['userfile'][‘new.txt'] ." uploaded successfully!</p><p>";
// displaying contents of the uploaded file
echo "Reading Contents of the file:</p><p>";
readfile($_FILES['userfile'][‘new.txt']);
} else {
echo "File ". $_FILES['userfile'][‘new.txt'] ." failed in uploading! File upload attack could be the reason!</p><p>";
}
?>输出
File new.txt uploaded successfully! Reading Contents of the file: This is demo text!
Let us see another example with file “details.txt”.
示例
Live Demo
<?php
$file = "newdetailstxt";
if(is_uploaded_file($file)) {
echo ("Uploaded via HTTP POST");
} else {
echo ("Not uploaded via HTTP POST");
}
?>输出
Not uploaded via HTTP POST!
