cannot match substring using regex_search

Question

Why this is failing ? I am trying to match a substring using regex in C++STL. What I am doing wrong here ?

GCC Version :: (Linaro GCC 4.8-2014.04) 4.8.3

#include<regex>
using namespace std;
int main()
{
        regex e("auth");
        smatch m;
        string s="Connected to a:b:c:d completed auth id=3, str=3";
        //string s="auth";

        bool match = regex_search(s,e);
        if( match == true )
                printf("matched");
        else
                printf("no match");
}

Galik · Answer 1 · 2015-05-07T19:10:10.717

0

According to the docs std::regex_match only matches the whole string. You probably want std::regex_search

#include<regex>
using namespace std;
int main()
{
        regex e("auth");
        smatch m;
        string s="Connected to a:b:c:d completed auth id=3, str=3";
        //string s="auth";

        bool match = regex_search(s,e);
        if( match == true )
                printf("matched");
        else
                printf("no match");
}

Also you should check if your implementation supports std::regex which is a new feature in C++11. For example the GCC compiler only properly implements <regex> in versions 4.9.0 and above.

edited May 07 '15 at 19:10

answered May 07 '15 at 19:07

Galik

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I have used regex_search also. It gives me the same result – Krishna M May 07 '15 at 19:08
@KrishnaM This code works for me, perhaps your compiler does not fully support regex? If using GCC need v4.9.0 or above, not sure about other compilers. – Galik May 07 '15 at 19:11
Works ok here: http://ideone.com/vAnj7h – PaulMcKenzie May 07 '15 at 19:12
I am using GCC Version 4.8.3 – Krishna M May 07 '15 at 19:12
@KrishnaM Then that's the problem :) – Galik May 07 '15 at 19:39

cannot match substring using regex_search

1 Answers1