Hello I have implemented a server in GO which reads data from a client and print it. For reading from the network stream, I am reading from the conn.Read() method on server.
Below is my code to read a byte from network stream
// return a single byte after reading from buffer
func readByte(conn net.Conn,buf []byte,numberofbytes *int,bufCurrPos *int) (byte){
fmt.Printf("Byte read")
if *bufCurrPos == *numberofbytes {
for {
*bufCurrPos = 0
*numberofbytes,_ = conn.Read(buf)
if *numberofbytes ==0 {
continue
} else {
break
}
}
}
b := buf[*bufCurrPos]
*bufCurrPos++
return b
}
Now I have created two client which write data to server.
First Client write to the stream using conn.Write() method while second method write to the stream using fmt.Fprintf(bufio.NewWriter(),format string) method.
Client 1
conn, err := net.Dial("tcp","localhost:8080")
if err != nil {
checkError(err)
}
go readHandler(conn)
for {
reader := bufio.NewReader(os.Stdin)
text, _ := reader.ReadString('\n')
conn.Write([]byte(text[0:len(text)-1]+"\r\n"))
}
client 2 :
name := "hi.txt"
contents := "bye"
exptime := 300000
conn, err := net.Dial("tcp", "localhost:8080")
if err != nil {
t.Error(err.Error()) // report error through testing framework
}
scanner := bufio.NewScanner(conn)
// Write a file
n,err := fmt.Fprintf(bufio.NewWriter(conn), "write %v %v %v\r\n%v\r\n", name, exptime, len(contents), contents)
if err !=nil {
fmt.Printf("error in writing in buffer\n")
}
Server read the data properly with first client but for the second client, it just read 0 byte always.
I am begginer in GO and don't know the reason for that. Could somebody please help me in that
The client2 application must flush the buffer.
bw := bufio.NewWriter(conn)
n,err := fmt.Fprintf(bw, "write %v %v %v\r\n%v\r\n", name, exptime, len(contents), contents)
bw.Flush()
The application should also check errors.
bw := bufio.NewWriter(conn)
_, err := fmt.Fprintf(bw, "write %v %v %v\r\n%v\r\n", name, exptime, len(contents), contents)
if err != nil {
// handle error
}
if err := bw.Flush(); err != nil {
// handle error
}
fmt.Fprintf buffers internally. If this is the only write to the connection, then remove the buffered writer.
_, err := fmt.Fprintf(conn, "write %v %v %v\r\n%v\r\n", name, exptime, len(contents), contents)
if err != nil {
// handle error
}
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