Do-while in Expect script

Question

I wrote the below code and try to execute it. But i face the \"invalid command name \"do\" while executing do {\"

code:

#!/usr/bin/expect
set val 0;
         


        

Answer 1

The short answer is no.

The slightly longer answer is:

while true {
    puts "\nval = $val"
    incr val
    if {[incr input -1] == 0} break
}

The full discussion can be found on the Tcl wiki.