Regular Expression:  get third field and only single instances

Posted on 2004-04-22
Last Modified: 2012-05-04
I need a   Regular Expression to add to the following

$mediaServerName = ($storageUnit =~

that will pull put the third line and place only single instances of the same field into the array. The $storageUnit  looks like:

STK9310_L00_DB00D02 2 db00d02 1 0 6 1 0 "*NULL*" 0 8 2000 *NULL*  
STK9310_L00_DB00M01 2 db00m01 1 0 6 4 0 "*NULL*" 0 2 2000 *NULL*  
STK9310_L00_DB00M01 2 db00m01 1 0 6 1 0 "*NULL*" 0 8 2000 *NULL*  

and I would like for the array to have db00d02 and db00m01.

NOT: db00d02 ,db00m01 and db00m01
Question by:MatthewF

Expert Comment

ID: 10887750
Hi MatthewF,
you can use a hash to ensure there is only a single instance

while(<>) {
  @line =split;
  if ( not $hsh{$line[0]}) {
    $hsh{$line[0]} = $line[2];

now you can traverse the hash and do what you like with it (store it in an array, print it etc.)

LVL 84

Accepted Solution

ozo earned 50 total points
ID: 10889554
$storageUnit = <<ENDHERE;
STK9310_L00_DB00D02 2 db00d02 1 0 6 1 0 "*NULL*" 0 8 2000 *NULL*  
STK9310_L00_DB00M01 2 db00m01 1 0 6 4 0 "*NULL*" 0 2 2000 *NULL*  
STK9310_L00_DB00M01 2 db00m01 1 0 6 1 0 "*NULL*" 0 8 2000 *NULL*
my %seen=(''=>1);
@array = grep{!$seen{$_}++}map{(split)[2]}split/\n/, $storageUnit ;

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