在c ++正则表达式上需要帮助

Question

I try to make following code work for my gcc 4.8.1 but i can't . if you need more information ,let me know. thank you so much

std::cmatch res;
std::string str = "<h2>I'm a piece of text</h2>";
std::regex rx("<h(.)>([^<]+)");
std::regex_search(str.c_str(), res, rx);
std::cout << res[1] << ". " << res[2] << "\n";

output:

2. Egg prices

according to chris, i need to wait gcc 4.9. if that, how does you implement this design in current gcc(not boost)? i want to Retrieve matches

Thanks again.

Answer 1

As per the error message, you gotta use another library, for example Boost.Regex

If you want to sanitize HTML you should consider using a more specialized technique. I personally do it through jsoup . Gumbo might work for C++. Also an XML parser will usually work.

Answer 2

I don´t have a boost env now to test (I´ll do it ASAP), but if you have, try something like:

#include<boost/regex>
#include<iostream>
#include<string>

int main(){

try{
  std::string str("<h2>I'm a piece of text</h2>");

  boost::regex rx("(<h[1-9]>)(.*)(<\\/h[1-9]>)");
  boost::sregex_iterator it(str.begin(), str.end(), rx);

  std::cout << << (*it)[1] << "\n"; // get group 1

 return 0;
}

Regex 101 is an excelent source to validade your regex!