CODEWITHSUNDEEP
socketstcl
user3365107
user3365107

Reputation: 238

exit vwait loop after client conection

I am trying to use this example from TCL wiki of server script:

    # Initialise the state
after 5000 set state timeout
set server [socket -server accept 12345]
proc accept {args} {
    global state connectionInfo
    set state accepted
    set connectionInfo $args
}

# Wait for something to happen
vwait state

# Clean up events that could have happened
close $server
after cancel set state timeout

# Do something based on how the vwait finished...
switch $state {
    timeout {
        puts "no connection on port 12345"
    }
    accepted {
       puts "connection: $connectionInfo"
       puts [lindex $connectionInfo 0] "Hello there!"
    }
}

I want that after the clinet open a socket with the server one time then vwait loop will finish and continue run,in case it's fail I will have a timeout.so far so good. The problem began when for some reason and I get an error with $state and cant run it as a function with a script. the error I get is: can't read "state": no such variable.altough running its as not a function works properly and I cant understand why. can anyone help me to fix this issue please??

Upvotes: 0

Views: 39

Answers (1)

Donal Fellows
Donal Fellows

Reputation: 137567

That code works, but only if it is evaluated in the global context; I guess you're trying to run it inside a procedure. What's happening is that the switch invocation looks for a local variable state instead of a global variable state, and doesn't find it, whereas vwait always works with global variables and after callbacks are evaluated in the global scope.

The fix is to replace

switch $state {

with

switch $::state {

Assuming you're happy with using that variable for nothing else.

Upvotes: 1

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