From: Tim Hunter <TimHunter@...>
Date: 2009-10-07T06:56:11+09:00
Subject: Re: Creating a pacifier in command line program

Jerry Mr wrote:
> I am trying to create a program that, at one part, replaces already
> displayed on the line with another.
> 
> For example:
> 
> Lets say the program is recursing directories.
> 
> It should display:
> 
> checking c:\Program Files\
> 
> then when it is done with that directory replace that line with the
> next, not create another below it.
> 
> I have been unable to locate information about this, though I don't
> really know what to call it.
> 
> Thank you.

I think this will work in Windows but I don't have it to test. It works 
in OS X and Linux terminal windows.

Instead of terminating the output line with a \n (or allowing it to 
default to a \n), use \r instead. "\r" is a carriage return, so the 
cursor will return to the start of the same line and overprint it.

For example,

10.times { |n| printf("Hello %d\r", n);sleep 1 }

Will print

Hello 0
Hello 1
Hello 2

etc., except each new "Hello" line overprints the previous one so you 
only see 1 line.

-- 
RMagick is looking for a maintainer. Email me if you're interested.