An example of a simple procedure:
% proc sayhi {} {
puts "hello world!"
puts "testing 1 2 3"
}
Yes, that's it. proc means that we are going to define a new
procedure. Next is the name of procedure (sayhi in this case), after
that the names of the parameters ({} means there are no parameters)
and at last the procedure body. sayhi can now be used like any other
command:
% sayhi hello world! testing 1 2 3
A procedure with some parameters:
% proc myproc {var1 var2} {
puts "var1 is var2"
}
% myproc hello world
var1 is hello
var2 is world
A procedure returning a value:
% proc multiply {var1 var2} {
return [ expr var2 ]
}
% puts [ multiply 3 27 ]
81
All parameters are passed by value and can't be changed.