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choose random text between constant string.. using awk?

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# 8  
Old 02-14-2010
Quote:
Originally Posted by sandwich
yes good question i have used

grep -c "^[%]" vtipy.txt
and the number was 2126

vtip=$RANDOM
let "vtip=1+(vtip%2125)" #thats why here is 2125 it is modulo
awk -v cislo=$vtip '/%/{p++;next}p==cislo' vtipy.txt
Smilie
# 9  
Old 02-14-2010
Hi.
Quote:
Originally Posted by ironmask2004
but you need to know how muche recoreds you have insaide the fill to generate a random number betwwen 1 and NUM Of Rec !!!
If one is willing to devote the time and effort, the reservoir sampling method allows one to extract a random sample in a single pass through a file. A brief explanation along with a python and perl code can be found at Program-o-Babble: Reservoir Sampling Algorithm in Python and Perl among many other places.

Best wishes ... cheers, drl
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