dzach 2006-5-9 Here is my first take on fconnect - a bidirectional channel copying procedure, kind of a bidirectional fcopy.
fconnect uses non blocking sockets to do copying from channel to channel. I guess it could be modified to use blocking channels too, if so needed.
# fconnect: bidirectionally connects two channels s1 s2
proc fconnect {s1 s2} {
fconfigure $s1 -blocking 0 -buffering none
fconfigure $s2 -blocking 0 -buffering none
fileevent $s1 readable [list copyData $s1 $s2]
fileevent $s2 readable [list copyData $s2 $s1]
}
# passes data from one channel to the other
proc copyData {from to} {
if {[eof $from]} {
close $from
close $to
return
}
puts -nonewline $to [read $from]
}That's it. The rest of the procs are used to stage a simple test:
# server side handling or new sockets
proc AcceptReq {sock ip port} {
incr ::cnt
set ::serv$::cnt $sock
puts "created ::serv$::cnt=$sock"
}
# client side handling of socket A
proc handleInputA sock {
if {[eof $sock]} {
close $sock
return
}
if {[gets $sock line]<1} {
return
}
puts "A: $line"
}
# client side handling of socket B
proc handleInputB sock {
if {[eof $sock]} {
close $sock
return
}
if {[gets $sock line]<1} {
return
}
puts "B: $line"
}Here is a test: copy data coming to server from A to B's side. Due to socket creation timings, commands should be typed (pasted in) one at a time, or errors might occure
set cnt 0
start a socket server for the test
socket -server AcceptReq 1234
create a client side socket, A, and configure it to print the data it receives
set A [socket localhost 1234]
fconfigure $A -blocking 0 -buffering line
fileevent $A readable [list handleInputA $A]create a client side socket, B, and configure it to print the data it receives
set B [socket localhost 1234]
fconfigure $B -blocking 0 -buffering line
fileevent $B readable [list handleInputB $B]connect the two channels together at server side
fconnect $serv1 $serv2
Now test the connection. Data sent to B gets copied at server side to A, so finally A receives it and prints it out
puts $B "Hello" # A: Hello
Same with A
puts $A "Hello" # B: Hello
I'm prety sure fconnect could be polished and optimized further, to suit other needs.