Hi Stuart, On Wednesday 01 September 2010 14:55:21 Kryten wrote: > Hi, > > I'm very much a beginner. > > Could anyone point me in the right direction on how to accomplish the > following, please? > > I have a fairly long log file call it file A, it has around 20,000 > lines of three element space separated variables. > > File A looks like:- > > 55223 jimmy smith > 55224 davy crocket > 55227 walter mitty > 63256 mickey mouse > .. > > I also have a .txt file with around 600 of the numbers found in file > A. Cal that File B. > > File B looks like:- > > 63256 > 55223 > .. > > I need to (quickly as possible) remove all the lines from File A, > whose numbers can be found in File B. > > Now, I have this working just fine in Windows Powershell, but it > really slow, as I am foreaching file b into a where-object filter, it > works but takes minutes to run. Based on my limited exposure to perl, > I'm pretty certain that TMTOWTDI !!
Use a hash: http://perl-begin.org/topics/hashes/ Populate the keys of the hash with the number of file B, read file A line by line and check if they exist in the hash to filter them out, while writing a new temporary file. Regards, Shlomi Fish -- ----------------------------------------------------------------- Shlomi Fish http://www.shlomifish.org/ Parody on "The Fountainhead" - http://shlom.in/towtf God considered inflicting XSLT as the tenth plague of Egypt, but then decided against it because he thought it would be too evil. Please reply to list if it's a mailing list post - http://shlom.in/reply . -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
