>>>>> "K" == Kryten <kryte...@googlemail.com> writes:
K> Here is what I have ( the least I can do is give you all a chance to
K> laugh
K> at my code! ):-
here comes the laughter! :)
K> #!/usr/bin/perl
K> use warnings ;
put use strict in there too. you are declaring some vars, strict
enforces that you declare all of them.
also i changed some names to use _ chars which makes them more readable.
K> my $names_file = 'C:\names.log' ;
K> my $exclude_list = 'C:\exclude.txt' ;
K> my %names_hash ;
K> open ( NAMES, $names_file ) ;
K> open ( EXCLUDE, $exclude_list ) ;
always check open calls for success. use lexical handles and not global
ones.
K> @allnames = <NAMES> ;
K> @allexcludes = <EXCLUDE> ;
if you want speed, that is not the best way to read in the file
lines. File::Slurp (on cpan) can do that for you and is cleaner as well:
use File::Slurp ;
my @all_names = read_file( $exclude_file ) ;
my @all_excludes = read_file( $names_file ) ;
and you can chomp an array which is faster than doing it for each line:
chomp @all_names ;
chomp @all_excludes ;
K> #---> Create the hash set #--->
K> foreach $exclusion ( @allexcludes ) {
K> chomp( $exclusion ) ;
K> $names_hash{ $exclusion } = 1
K> }
this may be more advanced than you want but you can use a slice for
this:
my %excluded_names ;
@excluded_names{ @all_excludes } = () ;
notice i didn't assign anything, all the entries will be undef. but they will
also i picked a better name. names_hash tells me nothing about the hash
K> #---> Walk the names array #--->
K> foreach $name ( @allnames ) {
K> chomp( $name ) ;
K> if ( ($dn) = $name =~ /(\d{5,6})/ ) {
K> if ( $names_hash{ $dn } ) {
if ( exists( $excluded_names{ $dn } ) ) {
K> print "This would be excluded: $name\n"
K> } # Close inner IF
useless comment. the indent tells you that. and any decent code editor
will handle checking of paired chars.
K> } # Close outer IF
K> }
K> This seems to work; I'm aghast at how quickly it tears through the
K> data.
K> My Powershell script was taking 2-3 minutes. This method completes in
K> about 4 seconds. Though to be fair I'm not using an associative array
K> in
K> my Powershell code, so it's not this same.
it isn't the language but the algorithm. a double loop as you likely
wrote in powershell is VERY slow. it would be N * M checks. with the
hash and one loop it is M times. so this is N times faster, easily
speeding up to 4 seconds vs 120-180 seconds.
K> This is an order of magnitude better than what I am doing now, so
K> big, big thanks and I'd be delighted for any pointers for how to
K> make my code more .. perl'ish.
my improvements will make your code more solid and even do a little more
speedup.
uri
--
Uri Guttman ------ u...@stemsystems.com -------- http://www.sysarch.com --
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