Easy way to remove extension from a filename?

I am trying to grab the raw filename without the extension from the filename passed in arguments:

int main ( int argc, char *argv[] )
{
    // Check to make sure there is a single argument
    if ( argc != 2 )
    {
        cout<<"usage: "<< argv[0] <<" <filename>\n";
        return 1;
    }

    // Remove the extension if it was supplied from argv[1] -- pseudocode
    char* filename = removeExtension(argv[1]);

    cout << filename;

}

The filename should for example be "test" when I passed in "test.dat".

Solution 1:

size_t lastindex = fullname.find_last_of("."); 
string rawname = fullname.substr(0, lastindex); 

Beware of the case when there is no "." and it returns npos

Solution 2:

This works:

std::string remove_extension(const std::string& filename) {
    size_t lastdot = filename.find_last_of(".");
    if (lastdot == std::string::npos) return filename;
    return filename.substr(0, lastdot); 
}