go - serving up pdfs using golang -

just wondering if guys can code.

it works serving images not pdf brochure. in advance

func main(){     http.handlefunc("/", func(w http.responsewriter, r *http.request){         filename    := "/var/www/filedipenser/brochure.pdf"          streampdfbytes, err := ioutil.readfile( filename )          if err != nil {             fmt.println(err)             os.exit(1)         }          b := bytes.newbuffer(streampdfbytes)          w.header().set("content-type", "application/pdf")          if _, err := b.writeto(w); err != nil {             fmt.fprintf(w, "%s", err)         }          w.write([]byte("pdf generated"))     })      err := http.listenandserve(":4111", nil)     if err != nil {         log.fatal("listenandserve: ", err)         fmt.println(err)     } } 

the code bit inefficient appears working. however, pdf viewers might sensitive extraneous output adding end of http response stream. remove w.write([]byte("pdf generated")) corrupting output. change fmt.println if wanted debugging purposes.

the inefficiency because loading entire pdf file memory send client. large files waste memory. better open file , stream directly file (an io.reader) response (an io.writer) using io.copy. like:

    // open file     f, err := os.open(filename)     if err != nil {         fmt.println(err)         w.writeheader(500)         return     }     defer f.close()      //set header     w.header().set("content-type", "application/pdf")      //stream response     if _, err := io.copy(w, f); err != nil {         fmt.println(err)         w.writeheader(500)     } 

you want handle errors better, example. however, important client provided http error response when encounter error aware request failed.