c++ 网络编程（七）TCP/IP LINUX下 socket编程 基于套接字的标准I/O函数使用 与 fopen,feof,fgets,fputs函数用法

#include <stdio.h>
main()
{
    FILE * fp = fdopen(0, "w+");
    fprintf(fp, "%s\n", "hello!");
    fclose(fp);
}

#include <stdio.h>
main()
{
     FILE   *fp;
     int   fd;
     fp = fopen("/etc/passwd", "r");
     fd = fileno(fp);
     printf("fd = %d\n", fd);
     fclose(fp);
}

include <stdio.h>
 
int main()
{
int str[100];
fputs(fgets(str, 100, strin), strout);
 
return 0;
}

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

#define BUF_SIZE 1024
void error_handling(char *message);

int main(int argc, const char * argv[]) {
    int serv_sock, clnt_sock;
    char message[BUF_SIZE];
    int str_len, i;

    struct sockaddr_in serv_adr, clnt_adr;
    socklen_t clnt_adr_sz;
    FILE *readfp;
    FILE *writefp;

    if(argc != 2)
    {
        printf("Usage: %s <port> \n", argv[0]);
        exit(1);
    }

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

    memset(&serv_adr, 0, sizeof(serv_adr));
    serv_adr.sin_family = AF_INET;
    serv_adr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_adr.sin_port = htons(atoi(argv[1]));

    if(bind(serv_sock, (struct sockaddr *) &serv_adr, sizeof(serv_adr)) == -1)
        error_handling("bind() error");

    if(listen(serv_sock, 5) == -1)
        error_handling("listen() error");
    clnt_adr_sz = sizeof(clnt_adr);

    for (i = 0; i < 5; i++) {
        clnt_sock = accept(serv_sock, (struct sockaddr *) &clnt_adr, &clnt_adr_sz);
        if(clnt_sock == -1)
            error_handling("accept() error");
        else
            printf("Connected client %d \n", i+1);

        //将文件描述符转换为FILE结构体指针
        readfp = fdopen(clnt_sock, "r");
        writefp = fdopen(clnt_sock, "w");
        while (!feof(readfp))
        {
            //转化为标准I/O操作
            fgets(message, BUF_SIZE, readfp);//相当于read，接收
            fputs(message, writefp); //相当于write，发送
            fflush(writefp); //刷新缓冲，立即显示而不是一直放缓冲中，保证立即将数据传输到客服端
        }
        fclose(readfp);
        fclose(writefp);
    }

    close(serv_sock);
    return 0;
}

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

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

#define BUF_SIZE 1024
void error_handling(char *message);

int main(int argc, const char * argv[]) {
    int sock;
    char message[BUF_SIZE];
    int str_len;
    struct sockaddr_in serv_adr;
    FILE *readfp;
    FILE *writefp;

    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_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("connect() error");
    else
        puts("Connected ...............");

    readfp = fdopen(sock, "r");
    writefp = fdopen(sock, "w");

    while (1)
    {
        fputs("Input message(Q to quit): ", stdout);
        fgets(message, BUF_SIZE, stdin);
        if (!strcmp(message, "q\n") || !strcmp(message, "Q\n"))
            break;

        fputs(message, writefp);
        fflush(writefp);
        fgets(message, BUF_SIZE, readfp);
        printf("Message from server : %s", message);
    }

    fclose(writefp);
    fclose(readfp);
    return 0;
}

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