6

I'm trying to convert an IP address that's inputted by a user so that I can perform some bitwise operations on it and a address already stored in a structure.

My problem is however that when the IP address is converted back the output is always 255.255.255.255. For example a input of 10.0.0.1 or 192.16.2.1 always returns 255.255.255.255.

struct sockaddr_in sa;
char ipinput[INET_ADDRSTRLEN];

fputs("Enter an IP Address: ", stdout);
fflush(stdout);

fgets(ipinput, sizeof ipinput, stdin);
inet_pton(AF_INET, ipinput, &(sa.sin_addr));
inet_ntop(AF_INET, &(sa.sin_addr), ipinput, INET_ADDRSTRLEN);
printf("IP Address = \"%s\" \n", ipinput);

2 Answers 2

6

You're not checking the value returned by inet_pton, you would have noticed it fails. As it turns out, it doesn't like the newline left in by fgets. Trim it:

ipinput[strlen(ipinput) - 1] = 0;
Sign up to request clarification or add additional context in comments.

Comments

1

Try to follow this:

inet_ntop(AF_INET, (void *)hent->h_addr_list[0],servIP,16);

inet_pton(AF_INET, hostIP, &(sa->sin_addr));

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.