A Tcl procedure is defined with the proc command. It takes three arguments:
proc name params body
The first argument is the procedure name, which is added to the set of commands understood by the Tcl interpreter. The name is case sensitive and can contain any characters. Procedure names do not conflict with variable names. The second argument is a list of parameter names. The last argument is the body of the procedure.
Once defined, a Tcl procedure is used just like any other Tcl command. When it is called, each argument is assigned to the corresponding parameter and the body is evaluated. The result of the procedure is the result returned by the last command in the body. The return command can be used to return a specific ...