1

I would like to understand why my program crashes when I try to use the wsregex::compile of BOOST with the following string:

(?P<path>\b[a-z]:\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*)?
(:)?
(?P<ip>(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b)
(;(?P<port>\d*))?
(:(?P<port>\b\d+\b):(?P<password>[\w]*))?
(:(?P<password>\b\d+\b))?

In regex buddy everything appears to be fine. I used the JGSoft flavor option on RegexBuddy.

I am validating the following:

c:\My Documents\Test\test.csv:1.12.12.13:111:admin
c:\My Documents\Test\test.csv:1.12.12.13:111
c:\My Documents\Test\test.csv:1.12.12.13;111
1.12.12.13:111
1.12.12.13;111

Can you guys help me. Thanks a lot.

Paulo Balbino
  • 57
  • 7

1 Answers1

1

This is neither a memory leak nor a crash as far as I can tell. Xpressive is throwing an exception because this is an invalid pattern. The following program:

#include <iostream>
#include <boost/xpressive/xpressive_dynamic.hpp>

namespace xpr = boost::xpressive;

int main()
{
    const char pattern[] =
        "(?P<path>\\b[a-z]:\\\\(?:[^\\\\/:*?\"<>|\\r\\n]+\\\\)*[^\\\\/:*?\"<>|\\r\\n]*)?"
        "(:)?"
        "(?P<ip>(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\b)"
        "(;(?P<port>\\d*))?"
        "(:(?P<port>\\b\\d+\\b):(?P<password>[\\w]*))?"
        "(:(?P<password>\\b\\d+\\b))?";
    try
    {
        xpr::sregex rx = xpr::sregex::compile(pattern);
    }
    catch(xpr::regex_error const & e)
    {
        std::cout << e.what() << std::endl;
    }
}

Outputs:

named mark already exists

Indeed, it does. This pattern uses "port" and "password" twice as the name of a capturing group. Xpressive doesn't like that. Just pick unique names for your captures and you should be fine.

Eric Niebler
  • 5,927
  • 2
  • 29
  • 43