go - Read whole data with Golang net.Conn.Read -

go - Read whole data with Golang net.Conn.Read -

so i'm building network app in go , i've seen conn.read reads limited byte array, had created make([]byte, 2048) , problem don't know exact length of content, much or not enough. question how can read exact amount of data. think have utilize bufio, i'm not sure.

it highly depends on you're trying do, , kind of info you're expecting, illustration if want read until eof utilize this:

func main() { conn, err := net.dial("tcp", "google.com:80") if err != nil { fmt.println("dial error:", err) homecoming } defer conn.close() fmt.fprintf(conn, "get / http/1.0\r\n\r\n") buf := make([]byte, 0, 4096) // big buffer tmp := make([]byte, 256) // using little tmo buffer demonstrating { n, err := conn.read(tmp) if err != nil { if err != io.eof { fmt.println("read error:", err) } break } //fmt.println("got", n, "bytes.") buf = append(buf, tmp[:n]...) } fmt.println("total size:", len(buf)) //fmt.println(string(buf)) }

//edit: completeness sake , @fabriziom's great suggestion, skipped mind:

func main() { conn, err := net.dial("tcp", "google.com:80") if err != nil { fmt.println("dial error:", err) homecoming } defer conn.close() fmt.fprintf(conn, "get / http/1.0\r\n\r\n") var buf bytes.buffer io.copy(&buf, conn) fmt.println("total size:", buf.len()) }

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