op_client.cpp

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 10240
void error_handling(char *message);

int main(int argc, char *argv[])
{
    int sock;
    char message[BUF_SIZE];
    int str_len,opnd_cnt, i;
    struct sockaddr_in serv_adr;
    
    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((char *)"socket() error");
    
    memset(&serv_adr, 0, sizeof(serv_adr));
    serv_adr.sin_family = AF_INET;
    serv_adr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_adr.sin_port = htons(atoi(argv[2]));

    if (connect(sock, (struct sockaddr *)&serv_adr, sizeof(serv_adr)) == -1)
        error_handling((char *)"connect() error!");
    else
        printf("连接成功!\n");

    char temp[20];
    puts("要计算的数字个数: ");
    scanf("%d",&opnd_cnt);
    sprintf(temp,"%d",opnd_cnt);
    strcat(temp," ");
    strcat(message,temp);
    for(i=0;i<opnd_cnt;i++)
    {
        printf("请输入第 %d 个数字:",i+1);
        scanf("%s",temp);
        strcat(temp," ");
        strcat(message,temp);
    }
    puts("请输入你要进行的运算符(+,-,*):");
    scanf("%s",temp);
    strcat(message,temp);
    write(sock,message,strlen(message));
    str_len= read(sock,message,BUF_SIZE -1);
    message[str_len]=0;
    printf("运算的结果:%s\n",message);
    return 0;

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