HTTP Upload: Handle files uploaded via Web forms

This class can be used to handle files that are uploaded to a server via Web forms.

It supports applying upload filters to restrict the files that are accepted according to configurable criteria like: file name extension, MIME type, file size, width and height in case the files are images.

It also supports handling uploads of multiple files.

It can also add prefixes to the uploaded file names, giving unique names or changing the file name extension for security reasons.

PHP code to identify uploaded file format
I need a code to identify the file format of uploaded file

upload .txt file
I need code for upload .txt file