dev/c/echo_server-udp/ip2int.c

33 lines
533 B
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>
unsigned int ip2int(const char *s)
{
int ip[4];
sscanf(s, "%d.%d.%d.%d", ip, ip + 1, ip + 2, ip + 3);
return ip[0] << 24 | ip[1] << 16 | ip[2] << 8 | ip[3];
}
int main(int argc, char *argv[])
{
if (argc < 2) {
perror("need ip address string");
exit(1);
}
printf("%X\n", ip2int(argv[1]));
return 0;
}