In a comment to the “Execute multiple commands at once” post, Michal has asked for a complete Tcl-shell-with-parameter example. Here's a short script that shuts down the interface and displays its status:

• Variable ifname is set to the value of the first command-line parameter (in many other programming languages, this would be written as argv[0]);
• If the ifname is empty, the script aborts and prints the usage guidelines (again, in a more human-oriented programming language, this would be if (ifname == “”) ...);
• The show ip interface ifname command is executed. If it fails, the interface name is not correct and the script aborts.
• IOS configuration commands interface ifname and shutdown are executed.
• The show ip interface brief configuration command is executed and filtered with the interface name.

#
# ifname is set to first CLI parameter (interface name)
#
set ifname [lindex $argv 0]
if {[string equal $ifname ""]} { puts "Usage: shutdown ifname"; return; }
if { [ catch { exec "show ip interface $ifname" } errmsg ] } {
  puts "Invalid interface $ifname, show ip interface failed"; return}

ios_config "interface $ifname" "shutdown"
puts [ exec "show ip interface brief ¦ include $ifname" ]