Simple text user interface question

Per Hedeland <>
Thu Aug 4 08:52:30 CEST 2005

"Vlad Dumitrescu" <> wrote:
>>I have to insert records in a database and would like to print the number
>inserted so far on a console. Is
>>there an easy way (without using slang, etc) to print the number always on
>the same line, the new
>>number overwriting the prior one (something like asking for a carriage
>return without a line feed)?

>The short answer is "not in a portable way".
>The long answer is "you can hack something up, for your own machine and
>environment, but it's probably more work than it's worth".

Hm, well, for cursor positioning in general that may be true, and I'm
sure there are *some* systems it would not work on, but for anything
that faithfully displays the text it receives doing exactly the
"something like" above works just fine - no ANSI support needed. I.e.
try this with e.g. l(1,10):

l(N,N) ->
l(M,N) ->
    io:format("\r~w   ", [M]),
    receive after 1000 -> ok end,

Will be a bit messy on a printing terminal, but should follow the spec
there too...:-)

--Per Hedeland

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