use strict;
my $str = 'bobs burgers dba bobs
100 Oceanside drive
nashville, tn 37204
bobs burgers dba bobs
100 attn Oceanside drive
nashville, tn 37204
bobs burgers dba bobs
100 Oceanside depth drive
nashville, tn fka 37204';
my $regex = qr/\b(attn|co|dba|fka|dept)\b.*/mp;
my $subst = '';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html