in reply to csv file is not opening using use strict
If the file exists your program should open it fine, atleast mine does (win7), however I think your mistake may be in the opening statement. the parameter '<' is the read only .. if the file has not yet been created and you want to create it use the '>' param. also the '>>' is used for appending. Sory if this doesnt help I am thinking of other reasons why you might be getting yelled at.
open(FILE,'>',"file.csv") or die;
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