how-to emulate head and tail in perl

      #

      # Reads a file trims the top and the bottom of by passed num of lines

      # and return the string 

      # stolen from : http://stackoverflow.com/a/9330343/65706

      # usage :       

      # my $StrCatFile = $objFileHandler->ReadFileReturnTrimmedStrAtTopBottom ( 

      #       $FileToCat , $NumOfRowsToRemoveAtTop , $NumOfRowsToRemoveAtBottom) ; 

      sub ReadFileReturnTrimmedStrAtTopBottom {

         my $self = shift ; 

         my $file = shift ; 

         my $NumOfLinesToRemoveAtTop = shift ; 

         my $NumOfLinesToRemoveAtBottom = shift ; 

         my @cache ; 

         my $StrTmp = () ; 

         my $StrReturn = () ; 

         my $fh = () ; 

         open($fh, "<", "$file") or cluck (   "can't open file : $file for reading: $!" ) ;

         my $counter = 0;

         while (<$fh>) {

             if ($. >= $NumOfLinesToRemoveAtTop + 1) {

                 $StrTmp .= $_ ;

             }

         } 

         close $fh;

         my $sh = () ; 

         open( $sh, "<", \$StrTmp) or cluck(   "can't open string : $StrTmp for reading: $!" ) ;

         while(<$sh>) {

             push ( @cache, $_  ) ;

             $StrReturn .= shift @cache if @cache > $NumOfLinesToRemoveAtBottom;

         }

         close $sh ; 

         return $StrReturn ; 

      } 

      #eof ReadFileReturnTrimmedStrAtTopBottom

      #

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