in reply to Seeking guidance on how to approach a task

Greetings,
Untested Suggestion 
#!/usr/bin/perl -w
use strict;

my %unique_values;

#open file two first and read in the values of interest
unless(open(F2, "file2name.txt")){
    die "a horrible death!";
}else{
    #line by line split off the first word i.e. user01, user02, etc
    %unique_values = map{ (split / /,$_)[0], undef }<F2>;
    close F2;
    unless(open(F1, "file1name.txt")){
        die "a horrible death!";
    }else{
        while(<F1>){
            chomp;
            if(exists($unique_values{$_}){
                delete $unique_values{$_});
            }
        }
        close F1;
    }
}
#open a file for output
unless(open(OUT, ">outputfile.txt")){
    die "again we fail!";
}else{
    print $_."\n" for(sort keys %unique_values);
    close OUT;
}

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Basically open the second file first... since its got the unique values of interest. Load in the values into a hash, for easy lookup, and open the first file. if the value is already in the hash delete it!

-InjunJoel
"I do not feel obliged to believe that the same God who endowed us with sense, reason and intellect has intended us to forego their use." -Galileo

Replies are listed 'Best First'.
Re^2: Seeking guidance on how to approach a task
by mark_nelson (Initiate) on Dec 19, 2005 at 16:27 UTC
    First, thank you to everyone for the replies. I apologize for the tardiness of my respnose back but I've been through airport hell this weekend and I'm just getting back to the task at hand.

    InjunJoel and SamCG:
    Thank you for posting the code and I'll read through it and definately learn from it!

    davies:
    A database is something I hadn't thought of. I might be able to get the change control to let me install mysql on the box altho I have minimal exposure to sql.

    TedPride:
    This process will only have to be run once a night so that helps from what I'm seeing in your post.

    graff:
    That makes sense too! Thank you for the code example!

    CountZero:
    Cpan! got it! I was reading some of that but there is alot to wade through!

    ambrus:
    I do have cygwin installed on the box so Join is an option.

    To all:

    Thank you for being so informative with your replies. I have multiple paths to look at and learn from. I am reading man pages and the camel book but its taking some time.

    mn

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