Changing working directories in Linux shell in a C program

My goal is to write a C program that is like a basic shell for Linux. I have everything working except changing working directories. I have tried the system() for input strings for cd and nothing happened. I also tried chdir("tokened string") and also no luck. Anyone have any ideas? This is part of my code:

        fgets(cmdStr, sizeof(cmdStr), stdin);

        if( strncmp("quit", cmdStr, 4) == 0 || strncmp("Quit", cmdStr, 4) == 0  )
        {
            break;
        }
        else if( strncmp("cd", cmdStr, 2) == 0 )
        {
            char *token = strtok(cmdStr, " ");
            token = strtok(NULL, " ");
            chdir(token);
        }
        else
        {
            system(cmdStr);
        }
    }

Is it possible to do this? Or is this a simple case of something to do with the child shell not being able to do certain things?

Edit: Code above is complete.

Answer

fgets() leaves the trailing 'n' character in cmdstr.

If you type cd foo, you’ll call chdir("foon") rather than chdir("foo").