inet_ntop() 在此范围内未清除

Question

I am building a TCP server using C: I included the library where the inet_ntop() function is (WS2tcpip.h), yet my compiler returns with the following error:

'inet_ntop' was not declared in this scope

I have no idea why; even my IDE doesn't notice anything wrong (I use vscode as my IDE because it can detect errors in real-time without compiling every time) yet when I compile it gcc returns the error I stated previously.

What I have included and defined:

#include <stdio.h>
#include <WS2tcpip.h>

#define WIN32_LEAN_AND_MEAN

#pragma comment (lib, "ws2_32.lib")

The faulty line of code:

if (getnameinfo((sockaddr*)&client, sizeof(client), host, NI_MAXHOST, service, NI_MAXHOST, 0) == 0) {
        printf("\n[CONNECTION]: %c connesso sulla porta %c", host, service);
    } else {
        inet_ntop(AF_INET, &client.sin_addr, host, NI_MAXHOST);
        printf("\n[CONNECTION]: %c connesso sulla porta %c", host, ntohs(client.sin_port));
    }

Any helpful tip is appreciated, thanks!

Answer 1

Are you working on Windows? If not, try including arpa/inet.h

Answer 2

Are you using VSCode? or manual compilers?

I have pretty same error with my code. Im using C++ in my code but I get error with these: 'getnameinfo' was not declared in this scope 'inet_ntop' was not declared in this scope

I use VS Code. What I realize is, when I copy paste same code to VS, it works! I think its something with compiler problem.

Still can't compile my code in VSCode but in VS it works.

Answer 3

Your compiler is most likely outdated and contains an outdated version of the <ws2tcpip.h> header which does not contain the inet_ntop function implementation.

I've had the same issue and resolved it by downloading MinGW-w64 9.0.0 with GCC 11.1.1 from here .