php - How do I send multiple files in same key in multi part formdata -

I need to send several files in a post request through the colon, but I need to identify them with the same key Something like the bottom

  ------ webkitfirmryfihaiki1 banks 0xj Content-Vision: form-data; Name = "blah [attachment] [] [resource]"; Filename = "abc.png" Content-Type: Image / PNG ------ WebKitformBoundaryFeature1Binie 0xj Content-Vision: Form-Data; Name = "blah [attachment] [] [resource]"; I am currently doing this  
  $ abc ['blah [attachments] [file] = "def.jpg" content-type: image / jpeg  
 < P>] [resource] '] = & gt;  

Which works fine for a single file but how do I send a request for multiple files as above?