Wapp

        set idx [string first $divider $body]
        set unit [string range $body 0 [expr {$idx-3}]]
        set body [string range $body [expr {$idx+$ndiv+2}] end]
        if {[regexp {^Content-Disposition: form-data; (.*?)\r\n\r\n(.*)$} \
             $unit unit hdr content] &&
            [regexp {name="(.*)"; filename="(.*)"\r\nContent-Type: (.*?)$}\
              $hdr hr name filename mimetype]} {
          dict set wapp $name.filename $filename
          dict set wapp $name.filename \
            [string map [list \\\" \" \\\\ \\] $filename]
          dict set wapp $name.mimetype $mimetype
          dict set wapp $name.content $content
        }
      }
    }
  }
}