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(gawk.info)Getline/Variable

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Using `getline' into a Variable
-------------------------------

   You can use `getline VAR' to read the next record from `awk''s input
into the variable VAR.  No other processing is done.  For example,
suppose the next line is a comment or a special string, and you want to
read it without triggering any rules.  This form of `getline' allows
you to read that line and store it in a variable so that the main
read-a-line-and-check-each-rule loop of `awk' never sees it.  The
following example swaps every two lines of input.  The program is as
follows:

     {
          if ((getline tmp) > 0) {
               print tmp
               print $0
          } else
               print $0
     }

It takes the following list:

     wan
     tew
     free
     phore

and produces these results:

     tew
     wan
     phore
     free

   The `getline' command used in this way sets only the variables `NR'
and `FNR' (and of course, VAR).  The record is not split into fields,
so the values of the fields (including `$0') and the value of `NF' do
not change.