C 查看和设置接收和发送缓冲区大小

get_set_socket_send_recv_buf.c

#include <sys/socket.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <assert.h>

int main(int argc, char **argv)
{
    int err = -1;       //返回值
    int s = -1;         //socket描述符
    int snd_size = 0;   //发送缓冲区大小
    int rcv_size = 0;   //接收缓冲区大小
    socklen_t optlen;   //选项值长度

    s = socket(PF_INET, SOCK_STREAM, 0);
    assert(s!=-1);

    //获取原始发送缓冲区大小
    optlen = sizeof(snd_size);
    err = getsockopt(s, SOL_SOCKET, SO_SNDBUF, &snd_size, &optlen);
    //获取原始接收缓冲区大小
    optlen = sizeof(rcv_size);
    err = getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcv_size, &optlen);
    printf(" 发送缓冲区原始大小为: %d 字节\n",snd_size);
    printf(" 接收缓冲区原始大小为: %d 字节\n",rcv_size);

    //设置发送缓冲区大小
    snd_size = 10*1024;     //发送缓冲区大小为8K
    optlen = sizeof(snd_size);
    err = setsockopt(s, SOL_SOCKET, SO_SNDBUF, &snd_size, optlen);

    //设置接收缓冲区大小
    rcv_size = 10*1024;
    optlen = sizeof(rcv_size);
    err = setsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcv_size, optlen);

    /*
     * 检查上述缓冲区设置的情况
     * 获得修改后发送缓冲区大小
     */
    optlen = sizeof(snd_size);
    err = getsockopt(s, SOL_SOCKET, SO_SNDBUF,&snd_size, &optlen);
    if(err<0){
        printf("获取发送缓冲区大小错误\n");
    }

    /*
     * 获得修改后接收缓冲区大小
     */
    optlen = sizeof(rcv_size);
    err = getsockopt(s, SOL_SOCKET, SO_RCVBUF,(char *)&rcv_size, &optlen);
    if(err<0){
        printf("获取接收缓冲区大小错误\n");
    }

    /*
     * 打印结果
     */
    printf(" 发送缓冲区大小为: %d 字节\n",snd_size);
    printf(" 接收缓冲区大小为: %d 字节\n",rcv_size);

    close(s);
    return 0;
}