'''American National Standards Institute''' see: http://www.ansi.org/.  Does standardization of all sorts of things.

One example that many programmers will have encountered is the [ASCII] character set, which was a huge improvement over the vast number of different manufacturer encodings in use beforehand (of which only [IBM]'s [EBCDIC] has survived in any meaningful way).

Also significant because, "ANSI escape codes are used to control text formatting and other output options on text terminals"
[http://en.wikipedia.org/wiki/ANSI_escape_code]. Terminal emulators for [Linux] have support for ANSI escape codes
built in.

[AM] (6 may 2014) The other day someone asked about controlling the output on screen, so that the last line would be rewritten with new results. Here is a simple solution which works with these ANSI escape codes. Unfortunately you only get the proper effect on Linux terminals and other ANSI-enabled terminals. 
The code is, however, dead simple:

   * Move the cursor to the right position (\escape[[10;0f)
   * Clear everything at this position and below (\escape[[J)
   * Write the new output

======
# showcomp.tcl --
#     Small program to illustrate the use of ANSI sequences
#

while {1} {
    puts -nonewline "\x1b\[10;1f\x1b\[J"
    puts "Result: [clock seconds] - [expr {rand()}]"
    puts "Computing ..."
    after 1000
}
======

<<categories>> Glossary