fwrite() and UTF8

Question

I am creating a file using php fwrite() and I know all my data is in UTF8 ( I have done extensive testing on this - when saving data to db and outputting on normal webpage all work fine and report as utf8.), but I am being told the file I am outputting contains non utf8 data :( Is there a command in bash (CentOS) to check the format of a file?

When using vim it shows the content as:

Donâ~@~Yt do anything .... Itâ~@~Ys a great site with everything....Weâ~@~Yve only just launched/

Any help would be appreciated: Either confirming the file is UTF8 or how to write utf8 content to a file.

UPDATE

To clarify how I know I have data in UTF8 i have done the following:

1. DB is set to utf8 When saving data

2. to database I run this first:

   $enc = mb_detect_encoding($data);

   $data = mb_convert_encoding($data, "UTF-8", $enc);

3. Just before I run fwrite i have checked the data with Note each piece of data returns 'IS utf-8'

   if (strlen($data)==mb_strlen($data, 'UTF-8')) print 'NOT UTF-8'; else print 'IS utf-8';

Thanks!

Answer 1

//add BOM to fix UTF-8 in Excel
fputs($fp, $bom =( chr(0xEF) . chr(0xBB) . chr(0xBF) ));

I find this piece works for me :)