If you read perlop's description of <> (the "null filehandle" in its nomenclature) it expands out the construct to: 

           unshift(@ARGV, '-') unless @ARGV;
           while ($ARGV = shift) {
               open(ARGV, $ARGV);
               while (<ARGV>) {
                   ...         # code for each line
               }
           }

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When you re-open any existing filehandle the underlying file is implicitly closed; so each time through the loop the prior file will be closed before the handle is reused.

In reply to Re^4: anonymous filehandes? by Fletch
in thread anonymous filehandes? by Anonymous Monk

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