Socket programming confusion with windows and unix/linux

Question

Hello I am trying socket programming in c++. I need confirmation or say rejection for this logic. I think socket.h header files are designed for UNIX systems whereas for Windows everything is done with winsock.h .

Is this correct?

Answer 1

For windows, you need winsock2.h and ws2tcpip.h .

On Linux, you need sys/socket.h and sys/types.h for the socket functions and netinet/in.h for the IP related structs.

Some other differences:

• Windows uses SOCKET for socket descriptors while Linux uses int
• Windows has closesocket() to close sockets, while Linux uses close()
• On Windows, you need to call WSAStartup() before calling any socket functions, and WSACleanup() when you are done using sockets.
• On Linux, you can print errors from socket functions using perror() or strerror() . On Windows, you have to call WSAGetLastError() to get the error code and FormatMessage to get the error text.

Answer 2

Most platforms implement a BSD-compatible socket API, however different platforms do use different .h files to declare their API. So, to answer your question, Yes, Windows uses winsock.h (and winsock2.h ), whereas POSIX-based platforms like Unix/Linux use sys/socket.h instead ( socket.h is defined as part of the POSIX standard, but Windows is not a POSIX-compatible platform). If you want to write cross-platform code, you have to take this into account. As well as other differences, which @dbush outlined in his answer.

Answer 3

Every header file starting with "sys/..." is designed for UNIX environment. As for windows, they tend to use "win" as a prefix to every header file they use.

If you are interested in windows sockets (winsocks) i guess you should start from here .

As for UNIX sockets, this site seems very interesting and easy going :)