#!/usr/bin/env tclsh

set SCALAR g
array set ARRAY {key1 value1 key2 value2}

set LIST [list a b c {def} {g h i j} k l m]

proc Wrap { body } {
  uplevel 1 $body
}

proc Main {} {
  global SCALAR
  set prefix "VAR: "
  Wrap {
    puts $SCALAR
    global ARRAY
    puts [array names ARRAY]

    set vars [list]
    foreach n [array names ::env] {
      set prefix "ENVVAR: $n = "
      puts "$prefix $::env($n)"
      lappend vars $n
    }
  }
  puts $vars
}

Main