c - 警告 : passing argument 2 of ‘memcpy’ makes pointer from integer without a cast [enabled by default]

Question

对于以下片段:

    /* get IP address on a specific network interface */
    void get_ip_dev(char* ipaddr, char* interface)
    {
            int fd;
            struct ifreq ifr;
            fd = socket(AF_INET, SOCK_DGRAM, 0);
            ifr.ifr_addr.sa_family = AF_INET;
            strncpy(ifr.ifr_name, interface, IFNAMSIZ-1);
            ioctl(fd, SIOCGIFADDR, &ifr);
            close(fd);
            memcpy(ipaddr, inet_ntoa(((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr), 20);
    }

我从 memcpy 收到警告，为什么？谢谢!

network.c: In function ‘get_ip_dev’:
network.c:39:43: warning: passing argument 2 of ‘memcpy’ makes pointer from integer without a cast [enabled by default]
/usr/include/string.h:44:14: note: expected ‘const void * __restrict__’ but argument is of type ‘int’

Answer 1

这应该是一个简单的修复:您需要包含 <arpa/inet.h> .编译器可能假设它返回 int。