use strict;
my $str = '1.43.7.112. Teste.
26.0.177. Teste.
1.1.1.1.1. Teste. Teste1.
1.1.1.1. Teste
1. Teste
1.43.7.112. Teste. 1.43.7.112. Teste.
1.43.7.112.
1.43.7.112. 123teste
1.43.7.112. _este.';
my $regex = qr/(\d+.)+ (\w)/p;
my $subst = '$2';
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