Unexpected results in matching a regex

[Dave]

#define BOOST_REGEX_DYN _LINK

#include <iostream>
#include <boost\regex.hp p>

using namespace boost;
using namespace std;

int main()
{
regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

// I would expect this to match, and it does.
cout << regex_match("\x F8p\x2Aqf\x0DPF FF", reg_exp) << endl;

// I would expect this to *not* match due to the 'w'.
// Why does it match?
cout << regex_match("\x F8p\x2Aqfw\x0DP FFF", reg_exp) << endl;
}

[Victor Bazarov]

Dave wrote:

#define BOOST_REGEX_DYN _LINK

#include <iostream>
#include <boost\regex.hp p>
Should change it to

#include <boost/regex.hpp>

and _never_ again use backslashes in the header name.

using namespace boost;
using namespace std;

int main()
{
regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

// I would expect this to match, and it does.
cout << regex_match("\x F8p\x2Aqf\x0DPF FF", reg_exp) << endl;

// I would expect this to *not* match due to the 'w'.
// Why does it match?
cout << regex_match("\x F8p\x2Aqfw\x0DP FFF", reg_exp) << endl;
}

Oh, did you try Boost online forum? What did they say?

V
--
Please remove capital As from my address when replying by mail

[Dave]

"Victor Bazarov" <v.********@com Acast.net> wrote in message
news:_U******** *******@newsrea d1.mlpsca01.us. to.verio.net...

Dave wrote:

#define BOOST_REGEX_DYN _LINK

#include <iostream>
#include <boost\regex.hp p>

Should change it to

#include <boost/regex.hpp>

and _never_ again use backslashes in the header name.

using namespace boost;
using namespace std;

int main()
{
regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

// I would expect this to match, and it does.
cout << regex_match("\x F8p\x2Aqf\x0DPF FF", reg_exp) << endl;

// I would expect this to *not* match due to the 'w'.
// Why does it match?
cout << regex_match("\x F8p\x2Aqfw\x0DP FFF", reg_exp) << endl;
}

Oh, did you try Boost online forum? What did they say?

V
--
Please remove capital As from my address when replying by mail

Actually, yes I did post to Boost, but my message has not yet appeared. Your
comment on backslashes contributes absolutely nothing to this thread.

[Andre Kostur]

"Dave" <be***********@ yahoo.com> wrote in news:11uk61b2s8 goc61
@news.supernews .com:

#define BOOST_REGEX_DYN _LINK

#include <iostream>
#include <boost\regex.hp p>

using namespace boost;
using namespace std;

int main()
{
regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

// I would expect this to match, and it does.
cout << regex_match("\x F8p\x2Aqf\x0DPF FF", reg_exp) << endl;

// I would expect this to *not* match due to the 'w'.
// Why does it match?
cout << regex_match("\x F8p\x2Aqfw\x0DP FFF", reg_exp) << endl;
}

You're asking in the wrong place.... that's not Standard C++. You'll be
much better off asking in the boost user's mailing lists and such.

[Victor Bazarov]

Dave wrote:

"Victor Bazarov" <v.********@com Acast.net> wrote in message
news:_U******** *******@newsrea d1.mlpsca01.us. to.verio.net...

Dave wrote:

#define BOOST_REGEX_DYN _LINK

#include <iostream>
#include <boost\regex.hp p>
Should change it to

#include <boost/regex.hpp>

and _never_ again use backslashes in the header name.

using namespace boost;
using namespace std;

int main()
{
regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

// I would expect this to match, and it does.
cout << regex_match("\x F8p\x2Aqf\x0DPF FF", reg_exp) << endl;

// I would expect this to *not* match due to the 'w'.
// Why does it match?
cout << regex_match("\x F8p\x2Aqfw\x0DP FFF", reg_exp) << endl;
}

Oh, did you try Boost online forum? What did they say?

V
--
Please remove capital As from my address when replying by mail

Actually, yes I did post to Boost, but my message has not yet appeared.

So, you're growing impatient, is that it? Generally, Boost functionality
is OT here. If you asked about std::tr1, you'd be closer to the topic of
this newsgroup.

Have you tried other tools, like Perl or 'sed' to see if the expression is
a match? No, I didn't. I just think that "\x2Aqfw" is not a match for
"\x2A..". You probably wanted to add another dot there.
Your
comment on backslashes contributes absolutely nothing to this thread.

Not true, it promotes healthy coding practices and that is always
a GOOD THING(tm).

V
--
Please remove capital As from my address when replying by mail

[Pete Becker]

Dave wrote:

int main()
{
regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

// I would expect this to match, and it does.
cout << regex_match("\x F8p\x2Aqf\x0DPF FF", reg_exp) << endl;

// I would expect this to *not* match due to the 'w'.
// Why does it match?
cout << regex_match("\x F8p\x2Aqfw\x0DP FFF", reg_exp) << endl;
}

I can't speak for the Boost implementation, but our TR1 implementation
gets the same result. It's a little clearer with a slight rewriting of
the regular expression. Yours was:

regex reg_exp("\xF8.\ x2A..\x0D(P|V)[0-9A-F]{3}");

In the ASCII encoding that's equivalent to:

regex reg_exp("\xF8.* ..\x0D(P|V)[0-9A-F]{3}");
And that embedded ".*.." will eat up two or more characters.

--

Pete Becker
Dinkumware, Ltd. (http://www.dinkumware.com)