# sock2.tcl

# Verbindung aufbauen
# zeilenweise Übertragung
proc Connect {} {
  global host port sock

  set sock [socket $host $port]
  fconfigure $sock -blocking 0 -buffering line
  fileevent $sock readable Read
  focus .in
  .in configure -background #ffffff
}

# Verbindung beenden
proc Disconnect {} {
  global sock

  close $sock
  set sock {}
  .in configure -background #000000
  return
}

# Eventroutine für empfangene Daten
proc Read {} {
  global sock

  # Verbindungsabruch -> Socket schließen
  if [eof $sock] {
    Disconnect
    return
  }
  # keine neuen Daten -> return
  if {[gets $sock line] < 0} {
    return
  }
  # Daten ausgeben
  .out insert end "$line\n"
  .out see end
  update idletasks
}

# Daten abschicken, sobald Enter gedrückt
proc Send {} {
  global sock

  if {$sock == {}} return
  set line [.in get "insert linestart" "insert lineend"]
  puts $sock $line
  flush $sock
}

# Main
# 1. GUI generieren
label .lh -text "Host:"
entry .eh -textvariable host
label .lp -text "Port:"
entry .ep -textvariable port
button .bc -text "Connect" -underline 0 -command Connect
button .bd -text "Disconnect" -underline 0 -command Disconnect
text .in -background #000000
text .out
grid .lh -row 0 -column 0
grid .eh -row 0 -column 1
grid .lp -row 1 -column 0
grid .ep -row 1 -column 1
grid .bc -row 2 -column 0
grid .bd -row 2 -column 1
grid .in -row 3 -column 0 -columnspan 2
grid .out -row 4 -column 0 -columnspan 2

# Shortcuts
bind . <Alt-Any-c> {Connect}
bind . <Alt-Any-d> {Disconnect}
# Behandlung Return bei Eingabe
bind .in <Return> Send
focus .eh

# Vorgabewerte
set host localhost
set port 80