Pull random line from a file

Scot Mc Pherson scot at linuxfromscratch.org
Fri Sep 6 10:39:07 PDT 2002


On Thu, 05 Sep 2002 18:16:23 -0400, Kevan Shea wrote:

> I want to pull a random line from a file in a bash script.  I can
> generate the random number fine, but how would I go about pulling a
> single line from a file?
> 
> I figure this is a one-line sed at worst, but I'm woefully lost by any
> sed that isn't s/find/replace/ and I can't figure what else I would
> use... fortune maybe?
 
that's easy...lets say that your random number is assigned to variable $i

the syntax would be:

sed -n /^.*$/s///${i}p inputfile > outputfile

which says:

-n = supress output ..  find pattern ^.*$ ( all whole lines  .. whihch means every line)
and switch ""  for "" which mean change nothing .. on the ${i}th line ...
and p = print the pattern space that is matched.

You'll have to test it, but that should do it.

Scot Mc Pherson
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