Hands-On Network Programming with C

Obtaining error descriptions

In Chapter 2, Getting to Grips with Socket APIs,  we developed the GETSOCKETERRNO() macro as a cross-platform way to obtain the error code after a failed system call.

The GETSOCKETERRNO() macro is repeated here for your convenience:

#if defined(_WIN32)#define GETSOCKETERRNO() (WSAGetLastError())#else#define GETSOCKETERRNO() (errno)#endif

The preceding code has served us well throughout this book. It has the advantage of being short and simple.

In a real-world program, you may want to display a text-based error message in addition to the error code. Windows and Unix-based systems both provide functions for this purpose.

We can build a simple function to return the last error message as a C string. The code for ...