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# This is an example of using Tcl's uplevel to create new control structures,
# and can be found on page 59 of "Exploring Expect" by Don Libes.
# Like variables declared global, variables declared static are
# accessible from other procedures. However, the same static variable
# cannot be accessed by procedures in different files.
#
# @param args The aguments to static are the same as global.
# @return Void, the side effect is manipulating the static state array.
proc static {args} {
    set unique [info script]

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# Replace whitespace characters with their escape codes
#
# @param str String containing some whitespace
# @return New string with escapes instead of whitespace
proc space2escape str {
    set escapes {
        \b \\b
        \f \\f
        \n \\n
        \r \\r

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# Draw a UTF-8 box around some text. Useful for pretty-printing, logging, etc.
#
# @param str String to draw box around
# @return String enclosed in a fancy box
proc box str {
    # Draw the top of the box
    #
    # @param length Number representing how long the top should be
    # @return String drawing the top of the box
    proc top length {

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# Format a list of lists into an evently-spaced table for logging etc.
#
# @param llst    List of lists to format.
# @param padding Optionally specify how many spaces to separate fields, defaults to four.
# @return String of the pretty table.
proc table {llst {padding 4}} {
    set lengths [lmap each [join $llst] {string length $each}]
    set longest [expr $padding + max([join $lengths ","])]

    foreach lst $llst {

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How to make Tcl Starpacks

Tcl scripts can be made into standalone executables for various platforms in what are called Starpacks. Statically linking Tcl libraries in a Starpack helps make Tcl programs more portable.

Building a Starpack requires:

1. The sdx tool.
2. A TclKit runtime for your operating system and architecture.

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#!/bin/env tclsh

# language should be a two-character ISO code
# languages must be installed using Argos GUI
set language_codes {
    ar de en es fr it zh
}

# CLI takes two arguments, ignore the rest
lassign $argv from_code to_code

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#!/bin/sh 
#
# How to prompt user input from an interactive text editor in POSIX shell.
# ======================================================================
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY

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#!/usr/bin/env tclsh
#
# How to read user input from an interactive text editor in Tcl
# =============================================================
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY

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How to make Tcl packages and modules

Tcl provides a package system that allows Tclers to share code. This package system supports two different formats that serve different use-cases:

1. The "package" or "8.5" format is more verbose, but allows package authors more flexibility through the pkgIndex.tcl file. This is designed for complex, multi-file programs.

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Intro

TCL-Expect scripts are an amazingly easy way to script out laborious tasks in the shell when you need to be interactive with the console. Think of them as a "macro" or way to programmaticly step through a process you would run by hand. They are similar to shell scripts but utilize the .tcl extension and a different #! call.

Setup Your Script

The first step, similar to writing a bash script, is to tell the script what it's executing under. For expect we use the following:

#!/usr/bin/expect