Reinhard Max - 2005-09-12
This piece of code can be added to any Tcl application to allow remote access from tkcon (or even telnet or netcat). To open the debugging socket, call
tkconclient::start ?port? ?myaddr?
The default value for myaddr is localhost. Applications that want to use this code need to run the Tcl event loop.
The code doesn't currently support concurrent client connections. Subsequent connection attempts are rejected if a connection is established already.
If the remote access capability isn't needed anymore, the command tkconclient::stop can be used to shut down the server socket, and the current client connection if there exists one. To shut down a client connection from the remote side, the word bye can be sent as a pseudo-command.
There is currently no access control to the socket!, so care must be taken, especially when opening debugging connections on a publically accessible interface.
namespace eval tkconclient {
variable script ""
variable server ""
variable socket ""
namespace export start stop
proc start {port {myaddr localhost}} {
variable socket
variable server
if {$socket ne "" || $server ne ""} stop
set server [socket -server [namespace current]::accept \
-myaddr $myaddr $port]
}
proc stop {} {
variable server
if {$server ne ""} {
closesocket
close $server
set server ""
}
}
proc closesocket {} {
variable socket
catch {close $socket}
set socket ""
# Restore [puts]
rename ::puts ""
rename [namespace current]::puts ::puts
}
proc accept {sock host port} {
variable socket
fconfigure $sock -blocking 0 -buffering none
if {$socket ne ""} {
puts $sock "Only one connection at a time, please!"
close $sock
} else {
set socket $sock
fileevent $sock readable [namespace current]::handle
# Redirect [puts]
rename ::puts [namespace current]::puts
interp alias {} ::puts {} [namespace current]::_puts
}
}
proc handle {} {
variable script
variable socket
if {[eof $socket]} {
closesocket
return
}
if {![catch {read $socket} chunk]} {
if {$chunk eq "bye\n"} {
puts $socket "Bye!"
closesocket
return
}
append script $chunk
if {[info complete $script]} {
catch {uplevel "#0" $script} result
if {$result ne ""} {
puts $socket $result
}
set script ""
}
} else {
closesocket
}
}
## This procedure is partially borrowed from tkcon
proc _puts args {
variable socket
set len [llength $args]
foreach {arg1 arg2 arg3} $args { break }
switch $len {
1 {
puts $socket $arg1
}
2 {
switch -- $arg1 {
-nonewline - stdout - stderr {
puts $socket $arg2
}
default {
set len 0
}
}
}
3 {
if {$arg1 eq "-nonewline" &&
($arg2 eq "stdout" || $arg2 eq "stderr")} {
puts $socket $arg3
} elseif {($arg1 eq "stdout" || $arg1 eq "stderr") \
&& $arg3 eq "-nonewline"} {
puts $socket $arg2
} else {
set len 0
}
}
default {
set len 0
}
}
## $len == 0 means it wasn't handled above.
if {$len == 0} {
global errorCode errorInfo
if {[catch [linsert $args 0 puts] msg]} {
regsub tkcon_tcl_puts $msg puts msg
regsub -all tkcon_tcl_puts $errorInfo puts errorInfo
return -code error $msg
}
return $msg
}
}
}