GoldClaw:
Thank you for your help.

I will clairify a bit but it looks like grep and map will help me.

What I do is this:
I have a list of trades in a tab seperated file.
The first and second line of the file looks like:
Date Sedol A/C # Country Currency B/S Shares Price (local) Cust Comm Rate Gross Comm (local) PNL (local) fx rate Gross PNL (USD) PNL (USD) tkts
07/04/01 6777007 1022578221 ZA ZAR S 10000 69.900000000 30.00 2097.00 1258.20 8.00 262.09 157.26 1.00

I need to calculate the profit and loss (PnL) from these trades.
The output needs to be things like:
1. a line for each client with the totals of each of the columns in the input file and some others which need to caluated. Client totals.
2. Total PnL for every client for a given country. Client vs country table with PnL totals as entries. this table is for a given date.
Process:
1. Based on the date range (user input) I collect all of the input files, cat them togeter into one.
2. open the file and line by line (trade by trade) I build the lists up. Client List, Country list, Total shares for a given Sedol list. (this is as far as I have gotten)(first perl application) :)
3. Now I want to put all of these trades in a big hash of arrays and say for all the countries in the traded country list build me a hash of arrays that countain trades done in those countries. (This is why there can not be two of the same countires listed.)
I want to pass this hash of arrays to the same function with the client list and have it return a hash of arrays for each client.
The I want to pass this hash of arrays to my PnL function and have it return the same hash of arrays with some new elements which are the things I need to print out to a file. PnL Costs charges etc....


This was the idea.

I wanted the country list, client list and total shares by sedol (this is the number form of a ticker) (actually I need to add date on to the array in the sedol total share function for each sedol total share array) to be global since I will need the for a lot of things.

The first sub ... build country list I think you understand and I see what you are doing. I thought that I would have to initialize the array by putting in one element the first time it was called. You are building a hash table with keys as the country and then just asking if if the country is allready in there and if not pushing it into an array.
Thanks!

The second sub it trying to do the same basic thing ... as I am reading in lines from the input file I want to build a structure, a hash of arrays, that contains the sedol the date of the that trade (which I can pass in as $date), and the total number of shares traded for that sedol. I need this later to caculate PnL for a given day. This was my first attempt at a hash.

IN reference to the code below:
The condition $mySellfirstflag is again trying to initialize the hash for the first time the sub is called. Same basic structure as the build client list.
I am trying to use the sedol as the key so that later I can find the total number of shares traded for a given date based on that sedol.

  if ($mySellfirstflag eq "YES") {
    %Sellhash = ($sedol => $shares); 
    #Do you mean that with mySellfirst that we should replace the shar
+es,
    #If so, the above line should be $Sellhash{$sedol}=$shares.
    #As it stands now, we replace the entire hash!!
[download]

Again in reference to the code below:
I thought that is how you assign the value to a given key???

      $Sellhash{$sedol} = $shares; #You did a .= here was that a typo?
[download]

Any thoughts?


Chris:
Is your @really_big_array an array of hashes? or what is this syntax? ... does smaller_array get filled with a list of fruits which point to apples?