use strict;
my $str = ' public void plugins_group_id_not_textual() throws IOException {
pluginsFailure("{" +
" \\"plugins\\": {" + "hola" +
" \\"onePlugin\\": {" +
" \\"groupId\\": 2" +
" }" +
" }" +
"}");';
my $regex = qr`\s*\+\s*\n(\s*)`p;
my $subst = '\\n\\1+ ';
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