[网络协议]linux客户端tcp连接打印自身IP

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
void error_handling(char* message);
int main(int argc, char* argv[]) {
    int sock;
    struct sockaddr_in serv_addr, client_addr;
    char client_addr_ip[20];

    if(argc != 3) {
        printf("Usage : %s <IP> <port>\n", argv[0]);
        exit(1);
    }

    sock = socket(PF_INET, SOCK_STREAM, 0);
    if(sock == -1)
        error_handling("socket() error");

    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));

    socklen_t client_addr_len = sizeof(client_addr);

    if(connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)
        error_handling("connet() error");

    getsockname(sock, (struct sockaddr*)&client_addr, &client_addr_len);
    inet_ntop(AF_INET, &client_addr.sin_addr, client_addr_ip, sizeof(client_addr_ip));

    printf("client_addr %s:%d\n", client_addr_ip, ntohs(client_addr.sin_port));
    close(sock);
    return 0;
}

void error_handling(char* message) {
    fputs(message, stderr);
    fputc('\n', stderr);
    exit(1);
}