dev/c/echo_server/int2ip.c

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <netdb.h>

static const char * int2ip(unsigned int ip) {
	static char s[16];
	sprintf(s,"%d.%d.%d.%d",ip>>24,ip<<8>>24,ip<<16>>24,ip<<24>>24);
	return s;
}

int main(int argc, char * argv[]) {
	if(argc < 2) {
		perror("need hex ip address");
		exit(1);
	}

	unsigned int ip = 0;
	sscanf(argv[1],"%X",&ip);

	printf("%s\n",int2ip(ip));

	return 0;
}