Unix Programming - Reading from a loop

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Author Reading from a loop
chaitu

2007-01-17, 1:17 pm

Hi,

I have a file as folows.

2400000
2399680
1896288
503392

And i am trying to read the numbers from this file and perform the
required calculations. I mean i want to divide (503392/2400000). How do
i do that?

Thanks in advance,

Krish

Pascal Bourguignon

2007-01-17, 1:17 pm

"chaitu" <chaituonweb@gmail.com> writes:
> I have a file as folows.
>
> 2400000
> 2399680
> 1896288
> 503392
>
> And i am trying to read the numbers from this file and perform the
> required calculations. I mean i want to divide (503392/2400000). How do
> i do that?
>
> Thanks in advance,


I don't see the relationship with loops.

(with-input-from-string (*standard-input* "
2400000
2399680
1896288
503392
")
(let ((divisor (read)) (dividend (progn (read) (read) (read))))
(/ dividend divisor)))

--> 15731/75000

--
__Pascal Bourguignon__ http://www.informatimago.com/

PLEASE NOTE: Some quantum physics theories suggest that when the
consumer is not directly observing this product, it may cease to
exist or will exist only in a vague and undetermined state.
Chris F.A. Johnson

2007-01-17, 7:28 pm

On 2007-01-17, chaitu wrote:
> Hi,
>
> I have a file as folows.
>
> 2400000
> 2399680
> 1896288
> 503392
>
> And i am trying to read the numbers from this file and perform the
> required calculations. I mean i want to divide (503392/2400000). How do
> i do that?


Use a loop that reads the file one line at a time. For example,
using the shell:

while read num
do
echo $(( $num / 2400000 ))
done < /path/to/file

--
Chris F.A. Johnson, author | <http://cfaj.freeshell.org>
Shell Scripting Recipes: | My code in this post, if any,
A Problem-Solution Approach | is released under the
2005, Apress | GNU General Public Licence
Logan Shaw

2007-01-17, 7:28 pm

chaitu wrote:
> I have a file as folows.
>
> 2400000
> 2399680
> 1896288
> 503392
>
> And i am trying to read the numbers from this file and perform the
> required calculations. I mean i want to divide (503392/2400000). How do
> i do that?


Here's a simple way to do that using the shell:

expr `tail -1 myfile` / `head -1 myfile`

I suspect you want something different than that, but that fits your
description, so maybe you should be more specific. :-)

- Logan
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