from perlop: 

 Conditional Operator

   Ternary "?:" is the conditional operator, just as in C. It works mu
+ch
   like an if-then-else. If the argument before the ? is true, the arg
+ument
   before the : is returned, otherwise the argument after the : is
   returned. For example:

       printf "I have %d dog%s.\n", $n,
               ($n == 1) ? '' : "s";

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for the gory details read on there ...

-- Hofmator

In reply to Re3: More efficient munging if infile very large (explain particular syntax?) by Hofmator
in thread More efficient munging if infile very large by ybiC

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