This works fine, thank you. But it is not exactly what I want, I guess my question wasn't clear enough. In the first list I want to start each line with a number divisble by 5 (x % 5 == 0), the second list should have numbers prepended that are odd, except for odd numbers that are divisble by 5. And different restrictions apply to the numbers of the third and the fourth list. In a test of the algorithm I used, I did this: 
@a = (0..100);
@b = map {if ($_ % 2 != 0 && $_ % 5 == 0){$_}} @a;
print @b;

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This works fine as far as producing the numbers I want concerns. The problem is that in the above example I use the $_. In the real script I cannot do that since the $_ has the present value of the list I am processing. best, ruben

In reply to Re^2: merging files using map by epistrophy
in thread merging files using map by epistrophy

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