实时系统
目录
任务一
-
学习使用Linux命令wc(1)
-
基于Linux Socket程序设计实现wc（1）服务器和客户端
- 客户端传一个文本文件给服务器
- 服务器返加文本文件中的单词数
wc命令
- 格式：
wc [选项]文件... - 功能：统计指定文件中的字节数、字数、行数，并将统计结果显示输出。该命令统计指定文件中的字节数、字数、行数。如果没有给出文件名，则从标准输入读取。wc同时也给出所指定文件的总统计数。
- 参数：
-c统计字节数-l统计行数-m统计字符数(这个标志不能与-c标志一起使用)-w统计字数。一个字被定义为由空白、跳格或换行字符分隔的字符串-L打印最长行的长度-help显示帮助信息--version显示版本信息
代码实现
服务器
#include<netinet/in.h> // sockaddr_in
#include<sys/types.h> // socket
#include<sys/socket.h> // socket
#include<stdio.h> // printf
#include<stdlib.h> // exit
#include<string.h> // bzero
#define SERVER_PORT 165326
#define LENGTH_OF_LISTEN_QUEUE 20
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int main(void)
{
// 声明并初始化一个服务器端的socket地址结构
struct sockaddr_in server_addr;
bzero(&server_addr, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = htons(INADDR_ANY);
server_addr.sin_port = htons(SERVER_PORT);
// 创建socket，若成功，返回socket描述符
int server_socket_fd = socket(PF_INET, SOCK_STREAM, 0);
if(server_socket_fd < 0)
{
perror("Create Socket Failed:");
exit(1);
}
int opt = 1;
setsockopt(server_socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
// 绑定socket和socket地址结构
if(-1 == (bind(server_socket_fd, (struct sockaddr*)&server_addr, sizeof(server_addr))))
{
perror("Server Bind Failed:");
exit(1);
}
// socket监听
if(-1 == (listen(server_socket_fd, LENGTH_OF_LISTEN_QUEUE)))
{
perror("Server Listen Failed:");
exit(1);
}
while(1)
{
// 定义客户端的socket地址结构
struct sockaddr_in client_addr;
socklen_t client_addr_length = sizeof(client_addr);
// 接受连接请求，返回一个新的socket(描述符)，这个新socket用于同连接的客户端通信
// accept函数会把连接到的客户端信息写到client_addr中
int new_server_socket_fd = accept(server_socket_fd, (struct sockaddr*)&client_addr, &client_addr_length);
if(new_server_socket_fd < 0)
{
perror("Server Accept Failed:");
break;
}
// recv函数接收数据到缓冲区buffer中
char buffer[BUFFER_SIZE];
bzero(buffer, BUFFER_SIZE);
if(recv(new_server_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
{
perror("Server Recieve Data Failed:");
break;
}
// 然后从buffer(缓冲区)拷贝到file_name中
char file_name[FILE_NAME_MAX_SIZE+1];
bzero(file_name, FILE_NAME_MAX_SIZE+1);
strncpy(file_name, buffer, strlen(buffer)>FILE_NAME_MAX_SIZE?FILE_NAME_MAX_SIZE:strlen(buffer));
printf("%s
", file_name);
// 打开文件，准备写入
FILE *fp = fopen(file_name, "w");
if(NULL == fp)
{
printf("File: %s Can Not Open To Write
", file_name);
exit(1);
}
// 从客户端接收数据到buffer中
// 每接收一段数据，便将其写入文件中，循环直到文件接收完并写完为止
bzero(buffer, BUFFER_SIZE);
int length = 0;
while((length = recv(new_server_socket_fd, buffer, BUFFER_SIZE, 0)) > 0)
{
if(strcmp(buffer,"OK")==0) break;
if(fwrite(buffer, sizeof(char), length, fp) < length)
{
printf("File: %s Write Failed
", file_name);
break;
}
bzero(buffer, BUFFER_SIZE);
}
// 接收成功后，关闭文件，关闭socket
printf("Receive File: %s From Client IP Successful!
", file_name);
fclose(fp);
// 统计文件单词个数，并发送给客户端
int words=0;
char s[100];
FILE *fp2;
if((fp2=fopen(file_name,"r"))==NULL){
printf("ERROR!
");
exit(0);
}
while(fscanf(fp2,"%s",s)!=EOF)
words++;
fclose(fp2);
//printf("%d words.
",words);
sprintf(buffer,"%d",words);
send(new_server_socket_fd,buffer,BUFFER_SIZE,0);
//send(new_server_socket_fd,&words,sizeof(words),0);
close(new_server_socket_fd);
// 关闭与客户端的连接
}
// 关闭监听用的socket
close(server_socket_fd);
return 0;
}
客户端
#include<netinet/in.h> // sockaddr_in
#include<sys/types.h> // socket
#include<sys/socket.h> // socket
#include<stdio.h> // printf
#include<stdlib.h> // exit
#include<string.h> // bzero
#define SERVER_PORT 165326
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int main()
{
// 声明并初始化一个客户端的socket地址结构
struct sockaddr_in client_addr;
bzero(&client_addr, sizeof(client_addr));
client_addr.sin_family = AF_INET;
client_addr.sin_addr.s_addr = htons(INADDR_ANY);
client_addr.sin_port = htons(0);
// 创建socket，若成功，返回socket描述符
int client_socket_fd = socket(AF_INET, SOCK_STREAM, 0);
if(client_socket_fd < 0)
{
perror("Create Socket Failed:");
exit(1);
}
// 绑定客户端的socket和客户端的socket地址结构 非必需
if(-1 == (bind(client_socket_fd, (struct sockaddr*)&client_addr, sizeof(client_addr))))
{
perror("Client Bind Failed:");
exit(1);
}
// 声明一个服务器端的socket地址结构，并用服务器那边的IP地址及端口对其进行初始化，用于后面的连接
struct sockaddr_in server_addr;
bzero(&server_addr, sizeof(server_addr));
server_addr.sin_family = AF_INET;
if(inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr) == 0)
{
perror("Server IP Address Error:");
exit(1);
}
server_addr.sin_port = htons(SERVER_PORT);
socklen_t server_addr_length = sizeof(server_addr);
// 向服务器发起连接，连接成功后client_socket_fd代表了客户端和服务器的一个socket连接
if(connect(client_socket_fd, (struct sockaddr*)&server_addr, server_addr_length) < 0)
{
perror("Can Not Connect To Server IP:");
exit(0);
}
// 输入文件名，并放到缓冲区buffer中等待发送
char file_name[FILE_NAME_MAX_SIZE+1];
bzero(file_name, FILE_NAME_MAX_SIZE+1);
printf("Please Input File Name On Client: ");
scanf("%s", file_name);
char buffer[BUFFER_SIZE];
bzero(buffer, BUFFER_SIZE);
strncpy(buffer, file_name, strlen(file_name)>BUFFER_SIZE?BUFFER_SIZE:strlen(file_name));
// 向服务器发送buffer中的数据
if(send(client_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
{
perror("Send File Name Failed:");
exit(1);
}
// 打开文件并读取文件数据
FILE *fp = fopen(file_name, "r");
if(NULL == fp)
{
printf("File:%s Not Found
", file_name);
}
else
{
bzero(buffer, BUFFER_SIZE);
int length = 0;
// 每读取一段数据，便将其发送给服务器，循环直到文件读完为止
while((length = fread(buffer, sizeof(char), BUFFER_SIZE, fp)) > 0)
{
if(send(client_socket_fd, buffer, length, 0) < 0)
{
printf("Send File:%s Failed./n", file_name);
break;
}
bzero(buffer, BUFFER_SIZE);
}
// 关闭文件
fclose(fp);
printf("File:%s Transfer Successful!
", file_name);
char s[50];
scanf("%s",s);
send(client_socket_fd,"OK",BUFFER_SIZE,0);
recv(client_socket_fd,buffer,BUFFER_SIZE,0);
printf("%d words.
",atoi(buffer));
}
close(client_socket_fd);
return 0;
}
实验截图
- wc指令执行
- 服务器客户端连接传输
任务二
使用多线程实现wc服务器并使用同步互斥机制保证计数正确
- 只需要改变任务一服务器代码即可。
- 增加多线程
- 使用同步互斥
代码实现
服务器
#include <stdio.h>
#include <fcntl.h>
#include <pthread.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#define PORT 165326
#define BUFF_SIZE 1024
typedef struct{
char type;
char data[BUFF_SIZE];
}m_package;
void* process_client();
int main(){
int ss = create_tcp_server(PORT);
if(-1 == ss)
exit(-1);
while(1){
//接受客户端连接
socklen_t addrlen = sizeof(struct sockaddr);
struct sockaddr_in client_addr; //客户端地址结构
int client_sock = accept(ss, (struct sockaddr*)&client_addr, &addrlen);
if(client_sock < 0){
printf("accept error
");
}
printf("accept success
");
pthread_t pid;
if(pthread_create(&pid, NULL, process_client, &client_sock) < 0){
printf("pthread_create error
");
}
}
}
//处理客户端程序
void *process_client(void *arg){
int size = 0, fd, count = 0, sockid = *(int*)arg;
m_package pac;
long total = 0, cur = 0;
//循环接收文件
while(1) {
memset(&pac, 0, sizeof(pac));
size = read(sockid, &pac, sizeof(pac));
if(size > 0){
if (pac.type == 1){
fd = open(pac.data, O_CREAT|O_WRONLY, 0777);
if(-1 == fd){
printf("open file error!
");
continue;
}
count = total = cur = 0;
}
else if (pac.type == 2){
cur += write(fd, pac.data, strlen(pac.data));
if(count++ % 5000 == 0){
printf("recv from client < %d > : %.01lf\%
", sockid, cur * 100.0 / total);
count = 0;
}
}
else if (pac.type == 3){
printf("recv from client < %d > : 100.0\%
", sockid);
printf("recv success
");
close(fd);
}
else if(pac.type == 4){//文件长度
total = strtol(pac.data, NULL, 10);
printf("%ld
", total);
}
}else{
printf("client disconnected
");
close(sockid);
break;
}
}
return 0;
}
实验截图
遇到的问题
bind：Address already in use
- Ctrl＋C强制结束进程
- 给套接字应用 SO_REUSEADDR 套接字选项，以便端口可以马上重用
- 使用
linux% netstat -tanlp和linux% kill (pid)指令切断有此端口号的进程。