How to upload PDF file with CodeIgniter

Open <root_directory>/system/application/config/mimes.php file

Change value of ‘pdf’ element of $mimes array

$mimes = array( ‘hqx’   =>      ‘application/mac-binhex40′,
‘cpt’   =>      ‘application/mac-compactpro’,
‘csv’   =>      array(‘text/x-comma-separated-values’, ‘text/comma-separated-values’, ‘application/octet-stream’, ‘application/vnd.ms-excel’, ‘text/csv’, ‘application/csv’, ‘application/excel’, ‘application/vnd.msexcel’),
‘bin’   =>      ‘application/macbinary’,
‘dms’   =>      ‘application/octet-stream’,
‘lha’   =>      ‘application/octet-stream’,
‘lzh’   =>      ‘application/octet-stream’,
‘exe’   =>      ‘application/octet-stream’,
‘class’ =>      ‘application/octet-stream’,
‘psd’   =>      ‘application/x-photoshop’,
‘so’    =>      ‘application/octet-stream’,
‘sea’   =>      ‘application/octet-stream’,
‘dll’   =>      ‘application/octet-stream’,
‘oda’   =>      ‘application/oda’,
‘pdf’   =>      array(‘application/pdf’, ‘application/x-pdf’),

To

‘pdf’   =>      array(‘application/pdf’, ‘application/x-pdf’, ‘application/x-download’,'application/x-download’, ‘binary/octet-stream’, ‘application/unknown’, ‘application/force-download’),