I'm not sure that using tell and seek leads to a more elegant solution (or at least I'm not sure how to use them to craft a more elegant solution).

I can only detect the start locations when I get to them (and the start-line has to be included in temp.dat).

Just to clarify - here is a simplified (and very short) version of export.dat:

100000001
200546Mary
200549#0002897
20055100001
100000003
200546Kathy
200547#0002530
200549#0002897
200552123 Elm Street
[download]

map{$a=1-$_/10;map{$d=$a;$e=$b=$_/20-2;map{($d,$e)=(2*$d*$e+$a,$e**2
-$d**2+$b);$c=$d**2+$e**2>4?$d=8:_}1..50;print$c}0..59;print$/}0..20
[download]

Kinda reminds me of an IRS "magnetic tape" file...

You're probably better off going with a process-as-you go model. I just usually go out of my way to avoid temp-files if I can. And I really like to go through a source file only once when possible.

When I suggested tell/seek, I was thinking you needed to see the end to find the start, but that probably ins't the case here so process-as-you-go is probably what you want.

-Paul

Me to (with regards to temp files) - the trouble is that NOT using a temp file would (afaik) double my memory requirements to 2 times the largest temp file.

Basically, the output_data routine steps through the temp-file line-by-line, pushing the data to various arrays, hashes, etc. - so not using a temp-file would mean that I end up allocating memory to the raw data as well as the various arrays and hashes which contain the processed data.

map{$a=1-$_/10;map{$d=$a;$e=$b=$_/20-2;map{($d,$e)=(2*$d*$e+$a,$e**2
-$d**2+$b);$c=$d**2+$e**2>4?$d=8:_}1..50;print$c}0..59;print$/}0..20
[download]

Tom Melly, pm@tomandlu.co.uk