Php uploads and downloads files using native functions

If ($ _ FILES & amp; $ _ FILES [attachment] & amp; $ _ FILES [attachment] [tmp_name]) {$ filesize $ _ FILES [attachment] [size]; file upload:

If ($ _ FILES & $ _ FILES ['attachment'] & $ _ FILES ['attachment'] ['tmp _ name']) {$ filesize = $ _ FILES ['attachment '] ['size']; // File upload size limit: 5 M if ($ filesize> 5*1024*1024) {exit ('the size of the uploaded file exceeds the limit! ');} // File storage directory. if not, create $ uploaddir = ROOT_DIR.'/public/attachment/notice/'. if (! File_exists ($ uploaddir) mkdir ($ uploaddir, 0755, true); // Get the Upload file extension $ arr_file = explode ('. ', basename ($ _ FILES ['attachment'] ['name']); $ filetype = $ arr_file [count ($ arr_file)-1]; // Obtain the source file name $ attachment_name = basename ($ _ FILES ['attachment'] ['name']); // rename the file to avoid the impact of Chinese characters $ fname = md5 (basename ($ _ FILES ['attachment '] ['name']). microtime ()). '. '. $ filetype; $ uploadfile = $ uploaddir. $ fname; if (move_uploaded_f Ile ($ _ FILES ['attachment'] ['tmp _ name'], $ uploadfile )) {// Obtain the relative file path $ attachment = '/public/attachment/notice /'. $ fname;} else {exit ('file Upload failed! ');}}

Note: "attachment" is the name of the uploaded file, which is modified according to the specific attribute values in the project. This upload process does not limit the file type. you can handle it as needed.

File download:

// Enter the file tag Header ("Content-type: application/octet-stream"); Header ("Accept-Ranges: bytes"); Header ("Accept-Length :". filesize ($ attachment_filepath); Header ("Content-Disposition: attachment; filename = ". $ attachment_filename); // output file content // read the file content and directly output it to the browser echo file_get_contents ($ attachment_filepath); exit ();