239 lines
8.3 KiB
Go
239 lines
8.3 KiB
Go
// =============================================================================
|
|
// Auth: Alex Celani
|
|
// File: server.go
|
|
// Revn: 10-02-2023 1.0
|
|
// Func: host connection, reply to speak.go
|
|
//
|
|
// TODO: fix remove
|
|
// write back to file, re-read file
|
|
// add more /codes/ to handle
|
|
// add flags
|
|
// =============================================================================
|
|
// CHANGE LOG
|
|
// -----------------------------------------------------------------------------
|
|
// 05-13-2022: init
|
|
// 08-29-2023: gutted and rewrote
|
|
// commented
|
|
// 09-12-2023: imported io/ioutil, strings, strconv
|
|
// added size conversation
|
|
// added file read function, fread()
|
|
// commented
|
|
// 09-21-2023: began rewrite of handle()
|
|
// 09-26-2023: got /list/ command working
|
|
// got /add/ command (mostly) working
|
|
//*10-02-2023: commented handle()
|
|
// added checks to /qr/ and /r2/ to make sure recv'd
|
|
// length is valid
|
|
// =============================================================================
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt" // Println
|
|
"io/ioutil" // ReadFile
|
|
"net" // ResovleTCPAddr, ListenTCP, listener.Accept
|
|
// conn.Read,Write
|
|
"os" // Exit
|
|
"strconv" // Itoa
|
|
"strings" // Split
|
|
)
|
|
|
|
|
|
// handle errors catastrophically
|
|
func check( err error ) {
|
|
if err != nil { // error is not nil on error
|
|
// print error
|
|
fmt.Println( "Fatal: ", err.Error() )
|
|
os.Exit( 1 ) // bail
|
|
}
|
|
}
|
|
|
|
|
|
// read file and create quote list
|
|
func fread() string {
|
|
// open file "quotes", read entire file as bytes into qfile
|
|
qfile, err := ioutil.ReadFile( "quotes" )
|
|
check( err ) // make sure read works
|
|
// cast bytes to string, split string over newline into array
|
|
qlist = strings.Split( string( qfile ), "\n" )
|
|
// remove last item in list ( trailing newline leaves empty item )
|
|
qlist = qlist[:len( qlist ) - 1]
|
|
if false { // XXX debug print ( next )
|
|
for _, q := range qlist { // iterate over all quotes in list
|
|
fmt.Println( q ) // print quote
|
|
}
|
|
}
|
|
return string( qfile ) // return file as string
|
|
}
|
|
|
|
|
|
// write qfile back to file
|
|
func writeFile( f string ) {
|
|
file, err := os.Create( "quotes" )
|
|
check( err )
|
|
_, err = file.WriteString( f )
|
|
check( err )
|
|
}
|
|
|
|
|
|
// handle connections ( new and improved )
|
|
func handle( conn net.Conn ) {
|
|
|
|
// create buffer to hold read message
|
|
var buffer [256]byte
|
|
// read n bytes from client
|
|
n, err := conn.Read( buffer[:] )
|
|
check( err ) // make sure read worked
|
|
|
|
// cast message to string, take first n bytes, split over @
|
|
command := strings.Split( string( buffer[:n] ), "@" )
|
|
|
|
// declare response string
|
|
var resp string
|
|
switch command[0] { // switch/case over opcode
|
|
case "sr": // /sr/, size request
|
|
// get length of list, convert to string
|
|
// XXX probably no reason to have this declaration scheme
|
|
var num string = strconv.Itoa( len( qlist ) )
|
|
// concat and send
|
|
resp = "sa@" + num // size answer
|
|
case "qr": // /qr/, quote request
|
|
// convert message argument to string to make sure it's a
|
|
// valid number
|
|
num, nerr := strconv.Atoi( command[1] )
|
|
// nerr will not be nil if comm[1] is not a number
|
|
if nerr != nil {
|
|
// formulate an error message
|
|
// TODO flesh this out more
|
|
resp = "ba@Number not understood" // bad answer
|
|
} else { // comm[1] was a number, but...
|
|
switch { // how do we know it's a valid number
|
|
case num > len( qlist ):
|
|
// bad answer in quote request
|
|
resp = "ba@qr@>"
|
|
// why bad? num is >
|
|
case num < 0:
|
|
// bad answer in quote request
|
|
resp = "bad@qr@-"
|
|
// why bad? num is -
|
|
default:
|
|
// good num, get quote, send off
|
|
resp = "qa@" + qlist[num] // quote answer
|
|
}
|
|
}
|
|
case "lr": // /lr/, list request
|
|
// just concat entire list to send
|
|
resp = "la@" + qfile[:len( qfile ) - 1] // list answer
|
|
// TODO what happens if this is longer than 256 char?
|
|
case "ar": // /ar/, add request
|
|
// append new quote to list
|
|
qlist = append( qlist, command[1] )
|
|
// also append new quote to file variable
|
|
qfile = qfile + command[1] + "\n"
|
|
writeFile( qfile )
|
|
resp = "aa@success" // add answer
|
|
// TODO write to file
|
|
case "r1": // /r1/, remove request 1
|
|
// same as list, just send whole file
|
|
resp = "r1@" + qfile // remove request 1
|
|
case "r2": // /r2/, remove request 2
|
|
// convert message argument to string to make sure it's a
|
|
// valid number
|
|
num, nerr := strconv.Atoi( command[1] )
|
|
// nerr will not be nil if comm[1] is not a number
|
|
if nerr != nil {
|
|
// formulate an error message
|
|
// TODO flesh this out more
|
|
resp = "ba@Number not understood" // bad answer
|
|
} else { // comm[1] was a number, but...
|
|
switch { // how do we know it's a valid number
|
|
case num > len( qlist ):
|
|
// bad answer in quote request
|
|
resp = "ba@r2@>"
|
|
// why bad? num is >
|
|
case num < 0:
|
|
// bad answer in quote request
|
|
resp = "ba@r2@-"
|
|
// why bad? num is -
|
|
default:
|
|
qlist[num + 1] = qlist[len( qlist ) - 1]
|
|
qlist = qlist[:len( qlist ) - 1]
|
|
var f string = ""
|
|
for _, v := range qlist {
|
|
f = f + v + "\n"
|
|
}
|
|
f = f[:len( f ) - 1]
|
|
qfile = f
|
|
writeFile( qfile )
|
|
resp = "r2@" + qfile
|
|
}
|
|
}
|
|
/*
|
|
resp = "r2@" // remove request 2
|
|
//
|
|
index, nerr := strconv.Atoi( command[1] )
|
|
if nerr == nil {
|
|
if index < len( qlist ) {
|
|
qlist[index] = qlist[len( qlist ) - 1]
|
|
qlist = qlist[:len( qlist ) - 1]
|
|
//writeFile() //TODO
|
|
resp = resp + "success"
|
|
} else {
|
|
resp = resp + "error"
|
|
}
|
|
} else {
|
|
resp = resp + "error"
|
|
}
|
|
*/
|
|
case "te": // /te/, transaction end
|
|
// TODO should I be sending something?
|
|
// TODO is it better to close now or outside of handle()
|
|
conn.Close() // close connection and leave
|
|
return // return from handle(), finish connection
|
|
default: // opcode not recognized
|
|
// TODO there should be more being down, here, right?
|
|
return // return from handle(), finish connection
|
|
}
|
|
|
|
// write response to client
|
|
_, err = conn.Write( []byte( resp ) )
|
|
check( err ) // make sure write worked
|
|
|
|
handle( conn ) // call handle() again to get response from client
|
|
|
|
}
|
|
|
|
|
|
// globals
|
|
var qlist []string // list of quotes
|
|
var qfile string // file object
|
|
var quit bool
|
|
|
|
|
|
// main, create port and wait for connection
|
|
func main() {
|
|
|
|
qfile = fread() // read quote file, init ( global ) list of quotes
|
|
|
|
service := ":1300" // create service on ip and port
|
|
|
|
// resolve ip address and port
|
|
addr, err := net.ResolveTCPAddr( "tcp", service )
|
|
check( err ) // make sure ip resolves
|
|
|
|
// create listener object from ip:port
|
|
listener, err := net.ListenTCP( "tcp", addr )
|
|
|
|
for {
|
|
// wait, create connection when found
|
|
conn, err := listener.Accept()
|
|
check( err ) // make sure connection works
|
|
|
|
go handle( conn ) // handle connection
|
|
}
|
|
|
|
os.Exit( 0 ) // exeunt
|
|
|
|
}
|
|
|