first mostly working draft

This commit is contained in:
2023-10-03 13:36:24 -04:00
parent 62da5f5a42
commit ad40edc558
2 changed files with 551 additions and 0 deletions
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// =============================================================================
// Auth: alex
// File: client.go
// Revn: 10-02-2023 1.0
// Func: ask server for a message of the day quote
//
// TODO: document
// add more flags?
// log errors in logfile
// =============================================================================
// CHANGE LOG
// -----------------------------------------------------------------------------
// 05-11-2022: init
// 05-17-2022: changed an entry in the response table
// 08-16-2023: copied from speak.go
// gutted, rewrote
// 09-12-2023: added size conversation
// added -d, -l, and -dest flags
// commented
// 09-21-2023: began complete-ass overhaul of handle() system
// wrote draft of draw()
// 09-26-2023: made draw return size and reference globals
// imported check() from soary
// 09-29-2023: commented handle()
//*10-02-2023: commented main(), and friends
//
// =============================================================================
package main
import (
"io" // io.EOF
"flag" // BoolVar, StringVar, Parse
"fmt" // Println
"math/rand" // NewSource, New, Intn, *rand.Rand
"net" // ResolveTCPAddr, DialTCP, conn.Write,Read
"os" // Exit
"strconv" // Atoi, Itoa
"strings" // Split
"time" // Now, UnixNano
)
// print errors if they occur, quit
func check( err error ) {
var errep string // declare error report string
switch err { // switch case over error input
case nil: // if there was no error
// then there was no error
errep = "err is nil"
case io.EOF: // if there was an End Of File error
errep = "Error: " + err.Error() // document error
conn.Close() // close connection
default: // anything besides those are a big deal
errep = "Fatal: " + err.Error()
}
var critical bool // declare critical error flag
// must be neither nil nor EOF
critical = err != nil && err != io.EOF
if critical { // XXX critical print
// TODO at some point, critical should be logging instead of
// printing, only verbose should print
fmt.Println( "check() -> ", errep )
}
if critical { // if there was a critical error
os.Exit( 1 ) // cut and run
}
}
// seed and get a new rng
func seed() *rand.Rand {
// use current time to seed random number
s := rand.NewSource( time.Now().UnixNano() )
r := rand.New( s ) // create new random number from seed
return r // return random number
}
// get a random number
func draw() string {
rn := seed() // get a random seed
r := rn.Intn( qsize ) // get a random number using seed
if debug { // XXX debug print
fmt.Println( "random number: ", r )
}
// convert random number to ascii, because converting
// ints to bytes ( for networking ) and back is obnoxious
rsz := strconv.Itoa( r )
if debug { // XXX debug print
fmt.Println( "converted size var" )
fmt.Printf( rsz + ": %T\n", rsz )
}
return rsz // return rand size
}
// get server response and print
func handle( conn net.Conn ) {
var buffer [512]byte // create buffer to hold response
// read n bytes from server into buffer ( byte slice )
n, err := conn.Read( buffer[:] )
check( err ) // check for errors
// split recv'd message over @, separate header from message
msg := strings.Split( string( buffer[:n] ), "@" )
var resp string // declare response variable
switch msg[0] { // switch/case over the header
// if message is...
case "sa": // /sa/, size answer
// convert back half to int, catch error
size, nerr := strconv.Atoi( msg[1] )
if nerr == nil { // if there was no error
qsize = size // set size global to recv'd size
} else {
// if int conversion failed, just quit
// TODO make more robust
os.Exit( 1 )
}
req := draw() // draw a random number
resp = "qr@" + req // create quote query with rng
case "ba": // /ba/, bad answer
// TODO create server-side, and handle client-side
fmt.Println( "error in " + msg[1] + ": " + msg[2] )
resp = "te@error" // set transaction end message
case "qa": // /qa/, quote answer
fmt.Println( msg[1] ) // whole-ass just print quote
resp = "te@success" // set transaction end message
case "la": // /la/, list answer
// split recv'd message over newline to create quote list
quotes := strings.Split( msg[1], "\n" )
for p, v := range quotes { // iterate over quotes
// print num of quote, followed by that quote
fmt.Println( p+1, "\t", v )
}
resp = "te@success" // set transaction end message
case "aa": // /aa/, add answer
// if server says add succeeded
if msg[1] == "success" {
fmt.Println( "Add successful" ) // print success
resp = "te@success" // set transaction end message
// if server says add failed
} else if msg[1] == "error" {
fmt.Println( "Add failed" ) // print fail
resp = "te@error" // set transaction end message
// unknown status message
} else {
// print unknown status
fmt.Println( "Unknown status code: " + msg[1] )
// TODO should this be unknown instead of error?
resp = "te@error" // set transaction end message
}
case "r1": // /r1/, remove ( first transaction )
// the idea is that if the user doesn't specify which quote to
// remove, list all quotes and let the user choose the quote
// to remove. There was probably a way to handle this a little
// more simply, but this, I feel, has some nuance to it that I
// actually like
// redo /la/, list all quotes
quotes := strings.Split( msg[1], "\n" )
for p, v := range quotes {
fmt.Println( p+1, "\t", v )
}
// TODO get user input
case "r2": // /r2/, remove ( second transaction )
// if server says remove succeeded
if msg[1] == "success" {
fmt.Println( "Remove successful" ) // print success
// list all quotes to validate remove succeeded
// TODO should /aa/ also make /lr/ before /te/?
resp = "lr@dumvar" // set transaction end message
// if server says remove failed
} else if msg[1] == "error" {
fmt.Println( "Remove failed" ) // print failure
resp = "te@error" // set transaction end message
// if unknown status message
} else {
// print unknown status
fmt.Println( "Unknown error code: " + msg[1] )
// TODO should this be unknown instead of error?
resp = "te@error" // set transaction end message
}
case "br": // /br/, bad request
// client has asked for something nonsensical
// TODO write out to file
fmt.Println( "Client sent a bad request" )
resp = "te@error" // set transaction end message
default: // something undefined entirely
// TODO write out to file
fmt.Println( "Message header not recognized" )
fmt.Println( msg )
conn.Close() // TODO how important is this line
return // dead return, essentially lets program quit
}
if debug { // XXX debug print
fmt.Print( "raw read: " + strconv.Itoa( n ) + " bytes " )
fmt.Println( buffer[:n] )
}
// send formulated response back to server
_, err = conn.Write( []byte( resp ) )
check( err ) // make sure write worked
handle( conn ) // call handle again
}
// globals
var qsize int // keep track of num of quotes
var conn net.Conn // keep track of connection
// global flag variables
var debug bool // debug prints useful information
var add bool // add new quotes to quote file ( on server )
var remove bool // remove quotes from quote file ( on server )
var list bool // request entire quote file from server
var dest string // provide a new destination ip and port
func main() {
// define flags
flag.BoolVar( &debug, "d", false, "print debug info" )
flag.BoolVar( &add, "a", false, "add quote to list" )
flag.BoolVar( &remove, "r", false, "remove quote from list" )
flag.BoolVar( &list, "l", false, "print quote list" )
flag.StringVar( &dest, "ip", ":1300", "ip:port of server" )
flag.Parse() // process flags
if debug { // XXX debug print
fmt.Println( "ip:port = ", dest )
}
service := dest // declare server ip:port
// create address object
addr, err := net.ResolveTCPAddr( "tcp", service )
check( err ) // check for errors
// make connection with object
conn, err = net.DialTCP( "tcp", nil, addr )
check( err ) // check for errors
// block for all flags
var command string
switch { // empty switch statement is basically an if
case list: // if list flag is active
command = "lr@dumvar" // list request
// TODO come up with a useful argument, instead of dumvar
case add: // if add flag is active
// if arguments were specified
if len( flag.Args() ) != 0 {
command = "ar@" // preface command w/ add request
// need to concat flag.args
for _, v := range flag.Args() {
// add the string and a space to command
command = command + v + " "
}
// remove the trailing space
command = command[:len( command ) - 1]
} else { // if no arguments were specified
// print that you need args and bail
fmt.Println( "/a/ flag must be used with an arugment" )
os.Exit( 1 )
}
case remove: // if remove flag is active
// if arguments were specified
if len( flag.Args() ) >= 0 {
// argument is supposed to the number of the quote to
// be removed, get first arg
// cast to int just to make sure it's a valid number
// assuming the user knows what they're doing
_, rerr := strconv.Atoi( flag.Args()[0] )
// if there was an error, just pretend there's no args
if rerr != nil {
command = "r1@dumvar" // remove request 1
// TODO come up w/ useful argument, replace dumvar
} else {
// if user knows the number, take care of it
// arg[0] is a string, so concat is cool
// jump right into remove request 2
command = "r2@" + flag.Args()[0]
}
} else { // if no argument was specified for remove
// jump right into remove request 1
command = "r1@dumvar"
}
default: // if no flag was specified
// begin transaction for quote request
command = "sr@please" // size request
}
// write command to server, beginning transaction
_, err = conn.Write( []byte( command ) )
check( err ) // make sure write worked
handle( conn ) // handle response
// TODO stack trace when handle returns, should probably be
// updated
conn.Close() // close connection when finished
os.Exit( 0 ) // exit
}
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// =============================================================================
// 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
}