id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
2188,Regex matches bad strings,koen@…,John Maddock,"I wrote the following small program to test if a string is a valid ip. The regex gives a false positive for the case listed below.
For comparison I've also added a perl program which does it correctly.

#include <iostream>
#include <boost/regex.hpp>

bool regex_match(const std::string &text, const std::string &match) {
  try {
    const boost::regex regex(match);
    boost::smatch matches;
    return boost::regex_match(text, matches, regex);
  } catch(boost::regex_error &e) {
    return false;
  }
}

int main() {
  if(regex_match(""1.2.03"", ""^(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])(\\.(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])){3}$"")) {
    std::cout << ""GOOD :)\n"";
  } else {
    std::cout << ""BAD  :(\n"";
  }
}

The corresponding perl program does it correctly:

if('1.2.03' =~ m/^(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])(\.(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])){3}$/) {
  print ""GOOD :)\n"";
}

",Bugs,closed,Boost 1.37.0,regex,Boost Development Trunk,Problem,fixed,regex false positive,