init
This commit is contained in:
@@ -0,0 +1,9 @@
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all: clean build
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clean:
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rm messagerA messagerB messagerC
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build:
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go build messagerA.go
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go build messagerB.go
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go build messagerC.go
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Executable
BIN
Binary file not shown.
@@ -0,0 +1,95 @@
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// =============================================================================
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// Auth: Alex Celani
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// File: messagerA.go
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// Revn: 05-04-2022 0.1
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// Func: Send message to another machine and then receive a single
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// response
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//
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// TODO: comment
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// =============================================================================
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// CHANGE LOG
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// -----------------------------------------------------------------------------
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// 05-04-2022: init
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//
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// =============================================================================
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package main
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import (
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"net" // ResolveTCPAddr, DialTCP, conn.Write,Read
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"os" // Exit, Stdin, Stderr, Args
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"fmt" // Println, Print, Fprintf
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"bufio" // NewScanner, NewScanner.Scan,Text
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"strings" // ToLower
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"time" // Now, Sub
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)
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// quick function to take user input
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func input( ps1 string ) string {
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fmt.Print( ps1 ) // print prompt
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scanner := bufio.NewScanner( os.Stdin ) // link to stdin
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scanner.Scan() // pull data
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return strings.ToLower( scanner.Text() ) // return lower text
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}
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// quick error checking
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func check( err error ) {
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// if user checks an error, it better be nil
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if err != nil {
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// put error in string, print in stderr
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fmt.Fprintf( os.Stderr, "Fatal error: %s", err.Error() )
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os.Exit( 2 ) // quit
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}
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}
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func main() {
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// if len is not 2 ( ./name host:port ), print usage and quit
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if len( os.Args ) != 2 {
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fmt.Fprintf( os.Stderr, "Usage: %s host:port", os.Args[0] )
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os.Exit( 1 )
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}
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service := os.Args[1] // capture ip address and host
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// "resolve" ip & host according to TCP rules
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tcpAddr, err := net.ResolveTCPAddr( "tcp", service )
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check( err ) // check error
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// "dial" ( establish connection ) to destination ip & port
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// according to TCP rules
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// laddr = nil -> local address is localhost
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conn, err := net.DialTCP( "tcp", nil, tcpAddr )
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check( err ) // check error
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var in string = input( ">> " ) // get user input
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start := time.Now() // start round trip timer
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// convert user input to bytes and send over connection
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_, err = conn.Write( []byte( in ) )
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check( err ) // check error
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var buf [512]byte // init byte array
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// read from connection into byte array
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// amount of bytes read stored in n
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//n, err := conn.Read( buf[0:] )
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n, err := conn.Read( buf[:] )
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check( err ) // check error
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t := time.Now() // stop round trip timer
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// convert read bytes into string and print
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fmt.Println( string( buf[:n] ) )
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fmt.Println() // newline to clean up a little
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fmt.Println( "rtt: ", t.Sub( start ) ) // print elapsed time
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os.Exit( 0 ) // exeunt
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}
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Executable
BIN
Binary file not shown.
@@ -0,0 +1,151 @@
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// =============================================================================
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// Auth: Alex Celani
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// File: messagerB.go
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// Revn: 05-10-2022 0.3
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// Func: Receive message, play with it, send to a third place, receive
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// response, send off to first place
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//
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// TODO: comment
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// =============================================================================
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// CHANGE LOG
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// -----------------------------------------------------------------------------
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// 05-04-2022: init
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// 05-05-2022: commented
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// 05-10-2022: added argument 'n' to alter() for halving purposes
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// changed passed value to alter()/forward() a slice
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//
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// =============================================================================
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package main
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import (
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"net" // ResolveTCPAddr, DialTCP, conn.Write,Read,Close
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// ListenTCP, listener.Accept
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"os" // Exit, Stderr, Stdin, Args
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"fmt" // Println, Fprintf
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"strings" // ToLower, ToUpper
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)
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// quick error checking
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func check( err error ){
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// if user checks an error, it better be nil
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if err != nil {
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// put error in string, print to stderr
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fmt.Fprintf( os.Stderr, "Fatal error: %s", err.Error() )
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os.Exit( 1 ) // quit
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}
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}
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// function to send message to third party and get response
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func quickSend( send string ) string {
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// ip:port
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// ip doesn't exist, implies localhost
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service := ":1202" // capture ip address and host
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// "resolve" ip & host according to TCP rules
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tcpAddr, err := net.ResolveTCPAddr( "tcp", service )
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check( err ) // check error
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// "dial" ( establish connection ) to destination ip & port
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// according to TCP rules
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// laddr = nil -> local address is localhost
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conn, err := net.DialTCP( "tcp", nil, tcpAddr )
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check( err ) // check error
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defer conn.Close() // barring any error, still close connection
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// convert user input to bytes and send over connection
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_, err = conn.Write( []byte( send ) )
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check( err ) // check error
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var buf [512]byte // init byte array
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// read from connection into byte array
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// amount of bytes read stored in n
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//n, err := conn.Read( buf[0:] )
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n, err := conn.Read( buf[0:] )
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check( err ) // check error
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return string( buf[:n] ) // return only written bytes
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}
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// function to change received message before passing it along
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func alter( recv []byte, n int ) string {
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var send string = string( recv[:n/2] )
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send = strings.ToUpper( send )
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fmt.Println( "to c: ", send )
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return send
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}
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// function to convert message to string before forwarding
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func forward( recv []byte ) string {
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return string( recv[:] )
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}
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// function to handle incoming connections
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func handleClient( conn net.Conn ) {
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defer conn.Close() // barring any error, still close connection
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var buf [512]byte // declare large byte array, store messages
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// iterate forever to always read over connection
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for {
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// read n bytes from connection into buffer
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n, err := conn.Read( buf[0:] )
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if err != nil { // erroring on read will simply leave the
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return // function so it can start again later
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}
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// print recv'd message
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// string() only works on byte SLICES so [:] is required
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fmt.Println( "recv: ", string( buf[:] ) )
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// var send string = string( buf[:n/2] )
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// send = strings.ToUpper( send )
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send := alter( buf[:], n ) // send message to get changed
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// send := forward( buf[:] )
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recv := quickSend( send ) // send message off
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fmt.Println( "из c: ", recv ) // print response
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// write that response back to original client
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_, err = conn.Write( []byte( recv ) )
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if err != nil { // erroring on write will simply leave the
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return // function so it can start again later
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}
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}
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}
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func main() {
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// ip:port
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// ip doesn't exist, implies localhost
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service := ":1201" // capture ip address and host
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// "resolve" ip & host according to TCP rules
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tcpAddr, err := net.ResolveTCPAddr( "tcp", service )
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check( err ) // check error
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// bind and "listen" to ip and port, according to tcp rules
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listener, err := net.ListenTCP( "tcp", tcpAddr )
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check( err ) // check error
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// iterate forever
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// TODO i mean i can totally make this more user friendly
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for {
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// accept a connection that makes its way to bound port
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conn, err := listener.Accept()
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if err != nil { // if connection fails...
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continue // don't quit program, not fatal error
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}
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// asynchronous function to handle connection to client
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go handleClient( conn )
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}
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}
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Executable
BIN
Binary file not shown.
@@ -0,0 +1,118 @@
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// =============================================================================
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// Auth: Alex Celani
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// File: messagerC.go
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// Revn: 05-10-2022 0.3
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// Func:
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//
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// TODO: create
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// =============================================================================
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// CHANGE LOG
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// -----------------------------------------------------------------------------
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// 05-04-2022: init
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// 05-09-2022: began commenting
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// 05-10-2022: finished commenting
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// added alter() and forward()
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// made passed value to alter()/forward() a slice
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// changed refs to recv byte array to slice of n bytes
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//
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// =============================================================================
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package main
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import (
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"net" // ResolveTCPAddr, conn.Write,Read,Close
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// ListenTCP, listener.Accept
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"os" // Args, Stderr, Exit
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"fmt" // Fprintf, Println
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"strings" // ToLower
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)
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// quick error checking
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func check( err error ) {
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// if user checks an error, it better be nil
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if err != nil {
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// put error in string, print in stderr
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fmt.Fprintf( os.Stderr, "Fatal error: %s", err.Error() )
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os.Exit( 2 ) // quit
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}
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}
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// function to change received message before passing it along
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func alter( recv []byte ) string {
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var send string = string( recv[:] )
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send = send + " " + send
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send = strings.ToLower( send )
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return send
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}
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// function to convert message to string before forwarding
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func forward( recv []byte ) string {
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return string( recv[:] )
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}
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// function to handle incoming connections
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func handleClient( conn net.Conn ) {
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defer conn.Close() // barring any error, still close connection
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var buf [512]byte // declare large byte array, store messages
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// iterate forever to always read over connection
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for {
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// read n bytes from connection into buffer
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n, err := conn.Read( buf[0:] )
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if err != nil { // erroring on read will simply leave the
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return // function so it can start again later
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}
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// print recv'd message
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// string() only works on byte SLICES so [:] is required
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fmt.Println( "recv: ", string( buf[:n] ) )
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send := alter( buf[:n] ) // send message ot get changed
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// send := forward( buf[:] )
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// write that response back to original client
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_, err = conn.Write( []byte( send ) )
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if err != nil { // erroring on write will simply leave the
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return // function so it can start again later
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}
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fmt.Println( "sent: ", send ) // print response
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}
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}
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func main() {
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// ip:port
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// ip doesn't exist, implies localhost
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service := ":1202" // capture ip address and host
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// "resolve" ip & host according to TCP rules
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tcpAddr, err := net.ResolveTCPAddr( "tcp", service )
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check( err ) // check error
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// bind and "listen" to ip and port, according to tcp rules
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listener, err := net.ListenTCP( "tcp", tcpAddr )
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check( err ) // check error
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// iterate forever
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// TODO i mean i can totally make this more user friendly
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for {
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// accept a connection that makes its way to bound port
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conn, err := listener.Accept()
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if err != nil { // if connection fails...
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continue // don't quit program, not fatal error
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}
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// asynchronous function to handle connection to client
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go handleClient( conn )
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}
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}
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Reference in New Issue
Block a user