private void LoadPerlRegex(byte[] pattern)
{
if (pattern == null) pattern = new byte[0];
int regex_start, regex_end;
StringBuilder upattern = new StringBuilder();
upattern.Append(pattern);
FindRegexDelimiters(upattern, out regex_start, out regex_end);
ParseRegexOptions(upattern, regex_end + 2, out dotNetOptions, out perlOptions);
perlRegEx = ConvertBytes(pattern, regex_start, regex_end - regex_start + 1);
}