我要成为嵌入式高手之3月7日Linux高编第十七天!!
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回顾
重要程序
1、UDP实现文件的发送
发端:
#include "head.h"
int main(void)
{
    int sockfd = 0;
    struct sockaddr_in recvaddr;
    ssize_t nsize = 0;
    int ret = 0;
    int fd = 0;
    char pathname[1024] = {0};
    char tmpbuff[1024] = {0};
    ssize_t nret;
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (-1 == sockfd)
    {
        perror("fail to socket");
        return -1;
    }
    recvaddr.sin_family = AF_INET;
    recvaddr.sin_port = htons(33333);
    recvaddr.sin_addr.s_addr = inet_addr("192.168.1.167");
    memset(pathname, 0, sizeof(pathname));
    gets(pathname);
    
    nsize = sendto(sockfd, pathname, strlen(pathname), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
    if (nsize == -1)
    {
        perror("fail to sendto");
        return -1;
    }
    
    fd = open(pathname, O_RDONLY);
    if (fd == -1)
    {
        perror("fail to open");
        return -1;
    }
    printf("pathname: %s\n", pathname);
    while (1)
    {
        usleep(10);
        nret = read(fd, tmpbuff, sizeof(tmpbuff));
        nsize = sendto(sockfd, tmpbuff, nret, 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
        if (nsize == -1)
        {
            perror("fail to sendto tmpbuff");
            return -1;
        }
        if (nret <= 0)
        {
            break;
        }
    }
    
    sprintf(tmpbuff, "|__quit__|");
    nsize = sendto(sockfd, tmpbuff, strlen(tmpbuff)+1, 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
    if (nsize == -1)
    {
        perror("fail to sendto tmpbuff");
        return -1;
    }
    printf("成功发送 %s 文件\n", pathname);
    close(fd);
    close(sockfd);
    return 0;
}
 
收端:
#include "head.h"
int main(void)
{
	int ret = 0;
	int sockfd = 0;
	char tmpbuff[4096] = {0};
	struct sockaddr_in recvaddr;
	ssize_t nsize = 0;
	struct sockaddr_in sendaddr;
	socklen_t len = sizeof(sendaddr);
	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd == -1)
	{
		perror("fail to socket");
		return -1;
	}
	recvaddr.sin_family = AF_INET;
	recvaddr.sin_port = htons(33333);
	recvaddr.sin_addr.s_addr = inet_addr("192.168.1.167");
	ret = bind(sockfd, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
	if (ret == -1)
	{
		perror("fail to bind");
		return -1;
	}
	nsize = recvfrom(sockfd, tmpbuff, sizeof(tmpbuff), 0, (struct sockaddr *)&sendaddr, &len);
	if (nsize == -1)
	{
		perror("fail to recvfrom");
		return -1;
	}
//	printf("%s:%d>>接受到%ld个字节:%s\n",inet_ntoa(sendaddr.sin_addr),ntohs(sendaddr.sin_port),nsize,tmpbuff);
	
	int fd = 0;
	char ch[1024]= {0};
	fd = open(tmpbuff,O_WRONLY | O_CREAT | O_TRUNC, 0664);
	if (fd == -1)
	{
		perror("fail to fopen");
		return -1;
	}
	while(nsize != 0)
	{
		memset(ch, 0, sizeof(ch));
		nsize = recvfrom(sockfd, ch, sizeof(ch), 0, (struct sockaddr *)&sendaddr, &len);
		if (nsize == -1)
		{
			perror("fail to recvfrom");
			return -1;
		}
		if (!strcmp(ch,"1"))
		{
			break;
		}
		write(fd,ch,nsize);
		printf("写入%ld字节\n",nsize);
	}
	printf("接受完成!\n");
	close(fd);
	close(sockfd);
	return 0;
} 
2、UDP实现全双工的聊天
发送端
#include "head.h"
char name[32] = {0};
int sockfd = 0;
struct sockaddr_in recvaddr;
pthread_t tid_send;
pthread_t tid_recv;
void *sendfun(void *arg)
{
    ssize_t nsize = 0;
    struct msgbuf sendmsg;
    
    while(1)
    {
        memset(&sendmsg, 0, sizeof(sendmsg));
        sendmsg.type = MSG_TYPE_CHAT;
        sprintf(sendmsg.name, "%s", name);
        gets(sendmsg.text);    
        if (!strcmp(sendmsg.text, ".quit"))
        {
            sendmsg.type = MSG_TYPE_END;
        }
        nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
        if (nsize == -1)
        {
            perror("fail to sendto");
            return NULL;
        }
        if (sendmsg.type == MSG_TYPE_END)
        {
            break;
        }
    }
    pthread_cancel(tid_recv);
    return NULL;
}
void *recvfun(void *arg)
{
    struct msgbuf recvmsg;
    ssize_t nsize = 0;
    while(1)
    {
        memset(&recvmsg, 0, sizeof(recvmsg));
        nsize = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, NULL, NULL);
        if (-1 == nsize)
        {
            perror("fail to recvfrom");
            return NULL;
        }
        if (recvmsg.type == MSG_TYPE_CHAT)
        {
            printf("%s(%s:%d)>%s\n", recvmsg.name, RECV_ADDR, RECV_PORT, recvmsg.text);
        }
        else if (recvmsg.type == MSG_TYPE_END)
        {
            break;
        }
    }
   
    pthread_cancel(tid_send);
    return NULL;
}
int main(void)
{
    ssize_t nsize = 0;
    struct msgbuf sendmsg;
    /*设置接收方信息*/
    recvaddr.sin_family = AF_INET;
    recvaddr.sin_port = htons(RECV_PORT);
    recvaddr.sin_addr.s_addr = inet_addr(RECV_ADDR);
    /*输入昵称*/
    printf("请输入您的昵称:\n");
    gets(name);
    
    /*创建套接字*/
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd == -1)
    {
        perror("fail to sockfd");
        return -1;
    }
    
    /*设置要发送的信息*/
    memset(&sendmsg, 0, sizeof(sendmsg));
    sendmsg.type = MSG_TYPE_START;
    sprintf(sendmsg.name, "%s", name);
    /*发送信息*/
    nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
    if (nsize == -1)
    {
        perror("fail to sendto");
        return -1;
    }
    pthread_create(&tid_send, NULL, sendfun, NULL);
    pthread_create(&tid_recv, NULL, recvfun, NULL);
    pthread_join(tid_send, NULL);
    pthread_join(tid_recv, NULL);
    
    close(sockfd);
    return 0;
}
 
接收端
#include "head.h"
char name[32] = {0};
int sockfd = 0;
struct sockaddr_in recvaddr;
struct sockaddr_in sendaddr;
pthread_t tid_send;
pthread_t tid_recv;
void *sendfun(void *arg)
{
    ssize_t nsize = 0;
    struct msgbuf sendmsg;
    
    while(1)
    {
        memset(&sendmsg, 0, sizeof(sendmsg));
        sendmsg.type = MSG_TYPE_CHAT;
        sprintf(sendmsg.name, "%s", name);
        gets(sendmsg.text);    
        if (!strcmp(sendmsg.text, ".quit"))
        {
            sendmsg.type = MSG_TYPE_END;
        }
        nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&sendaddr, sizeof(sendaddr));
        if (nsize == -1)
        {
            perror("fail to sendto");
            return NULL;
        }
        if (sendmsg.type == MSG_TYPE_END)
        {
            break;
        }
    }
    pthread_cancel(tid_recv);
    return NULL;
}
void *recvfun(void *arg)
{
    struct msgbuf recvmsg;
    ssize_t nsize = 0;
    while(1)
    {
        memset(&recvmsg, 0, sizeof(recvmsg));
        nsize = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, NULL, NULL);
        if (-1 == nsize)
        {
            perror("fail to recvfrom");
            return NULL;
        }
        if (recvmsg.type == MSG_TYPE_CHAT)
        {
            printf("%s(%s:%d)>%s\n", recvmsg.name, inet_ntoa(sendaddr.sin_addr), ntohs(sendaddr.sin_port), recvmsg.text);
        }
        else if (recvmsg.type == MSG_TYPE_END)
        {
            break;
        }
    }
   
    pthread_cancel(tid_send);
    return NULL;
}
int main(void)
{
    char tmpbuff[1024] = {0};
    struct msgbuf recvmsg;
    int ret = 0;
    socklen_t addrlen = sizeof(sendaddr);
    /*设置接收方信息*/
    recvaddr.sin_family = AF_INET;
    recvaddr.sin_port = htons(RECV_PORT);
    recvaddr.sin_addr.s_addr = inet_addr(RECV_ADDR);
    /*输入昵称*/
    printf("请输入您的昵称:\n");
    gets(name);
    
    /*创建套接字*/
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd == -1)
    {
        perror("fail to sockfd");
        return -1;
    }
    
    ret = bind(sockfd, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
    if (-1 == ret)
    {
        perror("fail to bind");
        return -1;
    }
    /*设置要发送的信息*/
    memset(&recvmsg, 0, sizeof(recvmsg));
    /*接收信息*/
    ret = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, (struct sockaddr *)&sendaddr, &addrlen);
    if (ret == -1)
    {
        perror("fail to recvfrom");
        return -1;
    }
    pthread_create(&tid_send, NULL, sendfun, NULL);
    pthread_create(&tid_recv, NULL, recvfun, NULL);
    pthread_join(tid_recv, NULL);
    pthread_join(tid_send, NULL);
    
    close(sockfd);
    return 0;
}
 
head.h
#ifndef _HEAD_H
#define _HEAD_H
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <dirent.h>
#include <time.h>
#include <pwd.h>
#include <stdlib.h>
#include <grp.h>
#include <sys/wait.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <arpa/inet.h>
struct msgbuf
{
    int type;      //消息类型
    char name[32]; //昵称
    char text[32]; //消息
};
#define MSG_TYPE_START        100               //开始聊天消息类型
#define MSG_TYPE_END          200               //退出聊天消息类型
#define MSG_TYPE_CHAT         300               //聊天消息类型
#define RECV_ADDR             "192.168.1.172"   //接收端地址
#define RECV_PORT             50000             //接收端端口
#endif
 
学习笔记
TCP通信
TCP发端(客户端)
socket -> connect -> send / recv-> close
TCP收端(服务端)
socket -> bind -> listen -> accept -> send / recv -> close
1、connect
#include <sys/types.h>          /* See NOTES */
 #include <sys/socket.h>
int connect(int sockfd, const struct sockaddr *addr,socklen_t addrlen);
功能:发起链接请求
参数:
sockfd:套接字的描述符
addr:目的地址存放空间首地址
addrlen:IP地址的大小
返回值:成功0,失败-1;
2、send
#include <sys/types.h>
 #include <sys/socket.h>
ssize_t send(int sockfd, const void *buf, size_t len, int flags);
功能:发送数据
参数:
sockfd:套接字描述符
buf:发送数据空间的首地址
len:发送数据的长度
flags:属性默认为0
返回值:
成功返回实际发送字节数
失败返回-1;
3、recv
#include <sys/types.h>
 #include <sys/socket.h>
ssize_t recv(int sockfd, void *buf, size_t len, int flags);
功能:接收数据
参数:
sockfd:套接字描述符
buf:存放数据空间首地址
len:最大接收数据的长度
flags:属性默认0
返回值:
成功返回实际接收字节数,失败返回-1;
若对方退出,返回0
客户端:
#include "head.h"
int main(void)
{
    int ret = 0;
    int sockfd = 0;
    struct sockaddr_in serveaddr;
    char tmpbuff[1024] = {0};
    ssize_t nsize = 0;
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (-1 == sockfd)
    {
        perror("fail to socket");
        return -1;
    }
    serveaddr.sin_family = AF_INET;
    serveaddr.sin_port = htons(50000);
    serveaddr.sin_addr.s_addr = inet_addr("192.168.1.101");
    ret = connect(sockfd, (struct sockaddr *)&serveaddr, sizeof(serveaddr));
    if (ret == -1)
    {
        perror("fail to connect");
        return -1;
    }
    gets(tmpbuff);
    nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);
    if (nsize == -1)
    {
        perror("fail to send");
        return -1;
    }
   
    memset(tmpbuff, 0, sizeof(tmpbuff));
    nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);
    if (nsize == -1)
    {
        perror("fail to recv");
        return -1;
    }
    printf("RECV: %s\n", tmpbuff);
    close(sockfd);
    return 0;
}
 

4、listen
#include <sys/types.h>          /* See NOTES */
 #include <sys/socket.h>
int listen(int sockfd, int backlog);
功能:监听客户端发送的链接请求,不会阻塞
参数:
sockfd:套接字描述符
backlog:允许等待的尚未被处理的三次握手请求的最大个数
返回值:成功0,失败-1;
5、accept
#include <sys/types.h>          /* See NOTES */
 #include <sys/socket.h>
int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);
功能:
处理等待链接队列中的第一个链接请求,若没有人发送链接请求会阻塞等待,直到有连接请求
参数:
sockfd:套接字描述符
addr:存放IP地址的空间首地址
addrlen:存放IP地址大小空间首地址
返回值:
成功返回一个新的文件描述符
失败返回-1;
服务端:
#include "head.h"
int main(void)
{
    int sockfd = 0;
    struct sockaddr_in serveaddr;
    int ret = 0;
    int confd = 0;
    ssize_t nsize = 0;
    char tmpbuff[1024] = {0};
    serveaddr.sin_family = AF_INET;
    serveaddr.sin_port = htons(50000);
    serveaddr.sin_addr.s_addr = INADDR_ANY;
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1)
    {
        perror("fail to socket");
        return -1;
    }
    ret = bind(sockfd, (struct sockaddr *)&serveaddr, sizeof(serveaddr));
    if (ret == -1)
    {
        perror("fail to bind");
        return -1;
    }
    ret = listen(sockfd, 10);
    if (-1 == ret)
    {
        perror("fail to listen");
        return -1;
    }
    confd = accept(sockfd, NULL, NULL);
    if (-1 == confd)
    {
        perror("fail to accept");
        return -1;
    }
    nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);
    if (-1 == nsize)
    {
        perror("fail to recv");
        return -1;
    }
    printf("RECV: %s\n", tmpbuff);
    memset(tmpbuff, 0, sizeof(tmpbuff));
    gets(tmpbuff);
    nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);
    if (-1 == nsize)
    {
        perror("fail to send");
        return -1;
    }
    close(confd);
    close(sockfd);
    return 0;
}
 
                


















