I don't see at first glance why your program would only loop once, but it seems to me that $_ is not set to a line from the file but a glob. I don't see why that is though. But you'll encounter other problems anyway.

Most operating systems have a limit on the number of files a program can have open at the same time. This limit is usually around 250 or around 1020, so you'll be hitting that limit with your 3000 files.

I would import all the CSV files into a database, for example SQLite is very convenient for that. If you can't even install SQLite anywhere, you can potentially even get along using a BTree database like DB_File, as your key is only a single column.

If you have the data in an SQL database, calculating the totals etc. becomes trivial, as SQL has the sum() and max() aggregates.

In reply to Re: agregating columns in several csv files by Corion
in thread agregating columns in several csv files by Utilitarian

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