There are many ways to find Hostname and IP address of a local machine. Here is a simple method to find hostname and IP address using C program.
We will be using the following functions :-
gethostname() : The gethostname function retrieves the standard host name for the local computer.
gethostbyname() : The gethostbyname function retrieves host information corresponding to a host name from a host database.
inet_ntoa() : The inet_ntoa function converts an (Ipv4) Internet network address into an ASCII string in Internet standard dotted-decimal format.
C/C++
// C program to display hostname // and IP address #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <netdb.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> // Returns hostname for the local computer void checkHostName(int hostname) { if (hostname == -1) { perror("gethostname"); exit(1); } } // Returns host information corresponding to host name void checkHostEntry(struct hostent * hostentry) { if (hostentry == NULL) { perror("gethostbyname"); exit(1); } } // Converts space-delimited IPv4 addresses // to dotted-decimal format void checkIPbuffer(char *IPbuffer) { if (NULL == IPbuffer) { perror("inet_ntoa"); exit(1); } } // Driver code int main() { char hostbuffer[256]; char *IPbuffer; struct hostent *host_entry; int hostname; // To retrieve hostname hostname = gethostname(hostbuffer, sizeof(hostbuffer)); checkHostName(hostname); // To retrieve host information host_entry = gethostbyname(hostbuffer); checkHostEntry(host_entry); // To convert an Internet network // address into ASCII string IPbuffer = inet_ntoa(*((struct in_addr*) host_entry->h_addr_list[0])); printf("Hostname: %s
", hostbuffer); printf("Host IP: %s", IPbuffer); return 0; } |
Output:
Hostname: cContainer Host IP: 10.98.162.101
Output varies machine to machine
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