Getting a text file rid of all superfluous blank lines

[Rodolfo Alcazar]

On Wed, 2005-11-30 at 12:42 +0000, Paul Smith wrote: 
> On 11/30/05, Tim <ignored_mailbox at yahoo.com.au> wrote:
> $ more file1.txt
> word1
> 
> 
> 
> word2
> 
> word3
> $ more -s file1.txt > file2.txt
> $ more file2.txt
> word1
> 
> 
> 
> word2
> 
> word3
> $
> 
> Tim's way works partially, i.e., many blank lines are in effect
> erased, but some remain. I suspect that the left blank lines are not
> blank lines although they look like blank lines. Can one go further
> with deleting the left "false" blank lines?

I did it this way:

cat file1 | grep -v "^[ ]*$"

supposing some lines could have no blanks (regex=/^$/) or some spaces
(regex for any number of spaces=/[ ]*/) 

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Rodolfo Alcazar - rodolfo.alcazar at padep.org.bo
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