Re^2: Deleting elements of one list using another

[suaveant]

in reply to Re: Deleting elements of one list using another
in thread Deleting elements of one list using another

Right idea but you aren't using anything to anchor the pattern, so you would also match 'JohnABC, CDE, 14'

@arr1 = ("0000007 | John | ABC.txt | 42","0000014 | Jane | XYZ.txt | 3
+4","0000017 | Jessica | GHI.txt | 21", etc);
@arr2 = ('0000007', '0000014');

my $re = join('|',@arr2);
my @arr3 = grep /^(?:$re)\s/, @arr1;

print join("\n",@arr3),"\n";