Do we have regular expression in C++ ?

indian · 03-06-2006, 04:55 AM

Hi,

I am looking to make a program in C++ which will be greatly solved by using regular expressions. Does C++ have default support of regular expression(i.e. inbuilt library) or do I need to get some external library to use it ? I am working on DevC++,windows by the way.A example will be really helpful.

Regards

Flesym · 03-06-2006, 05:26 AM

Well, I haven't used it for myself so far, but I know that the great "boost-library" (http://www.boost.org) offers a class for regular expressions. This library is also known to be very good documented, so you will surely get along with it.
http://www.boost.org/libs/regex/doc/index.html

aluser · 03-06-2006, 08:53 AM

There's also a C way to do it -- man 3 regex . I'd imagine the boost library makes it look better

indian · 03-06-2006, 09:33 AM

Hi, I have installed Boost for VC6 and refered to some online code. I have already added the library for VC6 and the code is giving me the following error:fatal error C1083: Cannot open include file: 'boost\function.hpp': No such file or directory All the paths are fine I guess..what can be the problem than.I hope asking such questions do not violate policies of LQ

Code:

#include <iostream>
#include <string>
#include <boost/shared_ptr.hpp>
using namespace std;
int main () {
  
  int i;
  string str="hello world";

  static const boost::regex e("hello world");
   i=regex_match(s, e);
   if(i!=1)
	   cout << "not matched";
  return 0;
}

Flesym · 03-06-2006, 09:54 AM

Are you sure, that your paths are correct? It looks to me, that you didn't add the boost directory (that contains the headers) to your include paths. So look where "boost\function.hpp" is located on your system and add this directory (the one that contains the "boost" subdirectory) to your include paths. It's a long time ago, since I last worked with VC6, but you should find these paths-settings somewhere under the menu Options/Projects/Directories/Include, or something similar.

EDIT:
Oh, and you should also add

Code:

#include <boost/regex.hpp>

And change the "s" (first parameter of 'regex_match') to "str". After doing so, the program worked fine for me. And don't forget to link against the boost regex library.