Check file uploaded is in csv format

Question

I am uploading a file in php and only want to upload it if it's a csv file. I believe my syntax is right for the content type. It always goes to else statement when it's a csv file. What I am doing wrong here?

if (($_FILES["file"]["type"] == "text/csv")) {  } else {  } 

If I change the content type it works for that format just not csv.

Answer 1

the mime type might not be text/csv some systems can read/save them different. (for example sometimes IE sends .csv files as application/vnd.ms-excel) so you best bet would be to build an array of allowed values and test against that, then find all possible values to test against.

$mimes = array('application/vnd.ms-excel','text/plain','text/csv','text/tsv'); if(in_array($_FILES['file']['type'],$mimes)){   // do something } else {   die("Sorry, mime type not allowed"); } 

if you wished you could add a further check if mime is returned as text/plain you could run a preg_match to make sure it has enough commas in it to be a csv.

Answer 2

There are a lot of possible MIME types for CSV files, depending on the user's OS and browser version.

This is how I currently validate the MIME types of my CSV files:

$csv_mimetypes = array(     'text/csv',     'text/plain',     'application/csv',     'text/comma-separated-values',     'application/excel',     'application/vnd.ms-excel',     'application/vnd.msexcel',     'text/anytext',     'application/octet-stream',     'application/txt', );  if (in_array($_FILES['upload']['type'], $csv_mimetypes)) {     // possible CSV file     // could also check for file content at this point }