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wxRegEx

Read the docs for wxRE_NEWLINE and wxRE_ADVANCED.

Remember you need to escape the backslash ('\') for strings, so you need to 'wxRegEx re("\\s", wxRE_ADVANCED)' for example

See Also: Official docs: wxRegEx

   wxString getExpresion( wxString &texto, wxString exp )
   {
       wxString result;
       wxRegEx expresion( _T( exp ) , wxRE_ADVANCED + wxRE_ICASE );//wxRE_ICASE | wxRE_DEFAULT
   
       if( expresion.IsValid() )
       {        
           if( expresion.Matches( texto ) )
           {
               result = expresion.GetMatch( texto, 1 );
           }
       }
       return result;
   }

call:

   getExpresion( htmldata, "(?w)href=\"([^\"]*)" );