Question

At some places in my code, I print debug messages like this:

int ret = getLinkSpeed(device.getSysName(), linkSpeed);
if (ret < 0)
{
    logDebug("Failed to obtain port speed for this device. Error: " + std::string(strerror(errno)));
}

From the documentation it is not entirely clear if strerror will return 0 under certain conditions (which would cause my code to crash). Does anyone know if it’s safe?

Answer 1

Why not write a function to do this:

string ErrStr() {
   char * e = strerror(errno);
   return e ? e : "";
}

This is easy to use, self-documenting, can be adapted to reformat the output and covers the possibility that strerror() might return NULL (I don’t know if it can).