Re: Removing users from a list

[Kenosis]

in reply to Removing users from a list

If I'm understanding your issue, you have two data sets. One contained in removelist.txt:

[e-mail]
[e-mail]
...

The other in masterlist.txt:

[e-mail]
[e-mail]
[e-mail]
[e-mail]<mailto:[e-mail]>
[e-mail]
[e-mail]
[e-mail]<mailto:[e-mail]>
...

You want items from the first set to be removed from the second. Excellent suggestions have been offered, and this is a "classic issue."

See if the following will work for your situation:

use Modern::Perl;
use File::Slurp qw/ read_file write_file /;

my $removeList = join '|',
    map { chomp; $_ } read_file 'removelist.txt';
    
write_file 'finallist.txt',
    grep !/$removeList/i, read_file 'masterlist.txt';

With the above two data sets, here is the output to finallist.txt:

[e-mail]
[e-mail]
[e-mail]
[e-mail]<mailto:[e-mail]>

The script only does what you mentioned, viz., joins the removelist.txt items with the pipe character (alternation operator) for a !"or" regex of email addresses used by grep on the masterlist.txt lines.

Hope this helps!

[CountZero]

To get a more efficient regular expression, use Regexp::Assemble to make your RE.

[Kenosis]

An excellent suggestion, CountZero...