2018-2019-1 20165336 實驗三 實時系統

任務一：

• 學習使用Linux命令wc(1)
  
  
  

查資料得到wc命令引數的意義 -c 統計位元組數。-l 統計行數。-m 統計字元數。這個標誌不能與 -c 標誌一起使用。-w 統計字數。一個字被定義為由空白、跳格或換行字元分隔的字串。-L 列印最長行的長度。--help 顯示幫助資訊。--version 顯示版本資訊。

• 基於Linux Socket程式設計實現wc（1）伺服器(埠號是你學號的後6位)和客戶端
  客戶端傳一個文字檔案給伺服器
  伺服器返加文字檔案中的單詞數
  
  

• 客戶端

#include<netinet/in.h>  
#include<sys/types.h>  
#include<sys/socket.h>  
#include<stdio.h>       
#include<stdlib.h>      
#include<string.h>     
#include<unistd.h>
#include<stdlib.h>
#define SERVER_PORT 165336
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int main()
{
    // 宣告並初始化一個客戶端的socket地址結構
    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);
    // 建立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);
    }
    // 繫結客戶端的socket和客戶端的socket地址結構 非必需
    if(-1 == (bind(client_socket_fd, (struct sockaddr*)&client_addr, sizeof(client_addr))))
    {
        perror("Client Bind Failed:");
        exit(1);
    }
    // 宣告一個伺服器端的socket地址結構，並用伺服器那邊的IP地址及埠對其進行初始化，用於後面的連線
    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);
    // 向伺服器發起連線，連線成功後client_socket_fd代表了客戶端和伺服器的一個socket連線
    if(connect(client_socket_fd, (struct sockaddr*)&server_addr, server_addr_length) < 0)
    {
        perror("Can Not Connect To Server IP:");
        exit(0);
    }
    // 輸入檔名 並放到緩衝區buffer中等待發送
    char file_name[FILE_NAME_MAX_SIZE+1];
    bzero(file_name, FILE_NAME_MAX_SIZE+1);
    printf("請輸入要傳送的檔名:\t");
    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));   
    // 向伺服器傳送buffer中的資料
    if(send(client_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
    {
        perror("Send File Name Failed:");
        exit(1);
    }   
    //int count=0;
    int length=0;
    bzero(buffer, BUFFER_SIZE);
    length = recv(client_socket_fd, buffer, BUFFER_SIZE, 0);
    buffer[length] = '\0';
    printf("伺服器返回文字檔案中單詞數為%s\n", buffer);
    bzero(buffer, BUFFER_SIZE);   
    /* / 開啟檔案，準備寫入
     / FILE *fp = fopen(file_name, "w");
    if(NULL == fp)
    {
        printf("File:\t%s Can Not Open To Write\n", file_name);
        exit(1);
    }
    / 從伺服器接收資料到buffer中    
    / 每接收一段資料，便將其寫入檔案中，迴圈直到檔案接收完並寫完為止
    bzero(buffer, BUFFER_SIZE);
    int length = 0;
    while((length = recv(client_socket_fd, buffer, BUFFER_SIZE, 0)) > 0)
    {
        if(fwrite(buffer, sizeof(char), length, fp) < length)
        {
            printf("File:\t%s Write Failed\n", file_name);
            break;
        }
        bzero(buffer, BUFFER_SIZE);
    }
    / 接收成功後，關閉檔案，關閉socket
    printf("Receive File:\t%s From Server IP Successful!\n", file_name);
    fclose(fp);
    */
    close(client_socket_fd);
    return 0;
}
 

• 伺服器

#include<netinet/in.h>  
#include<sys/types.h>   
#include<sys/socket.h>  
#include<stdio.h>     
#include<stdlib.h>     
#include<string.h>      
#include<unistd.h>
#define SERVER_PORT 165336
#define LENGTH_OF_LISTEN_QUEUE 20
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int CountWordsOfEuropeanTxtFile(char *szFileName);
int CountWordsInOneLine(const char *szLine);
int main(void)
{
    // 宣告並初始化一個伺服器端的socket地址結構
    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);
   // 建立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));
 // 繫結socket和socket地址結構
    if(-1 == (bind(server_socket_fd, (struct sockaddr*)&server_addr, sizeof(server_addr))))
    {
        perror("Server Bind Failed:");
        exit(1);
    }
     // socket監聽
    if(-1 == (listen(server_socket_fd, LENGTH_OF_LISTEN_QUEUE)))
    {
        perror("Server Listen Failed:");
        exit(1);
    }
while(1)
    {
        // 定義客戶端的socket地址結構
        struct sockaddr_in client_addr;
        socklen_t client_addr_length = sizeof(client_addr);
 // 接受連線請求，返回一個新的socket(描述符)，這個新socket用於同連線的客戶端通訊
        // accept函式會把連線到的客戶端資訊寫到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函式接收資料到緩衝區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;
        }
        // 然後從buffer(緩衝區)拷貝到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("20165336伺服器收到的檔案為:%s\n", file_name);
    int count=0;
    bzero(buffer, BUFFER_SIZE);
    count = CountWordsOfEuropeanTxtFile(file_name);
    sprintf(buffer,"%d", count);
        if(send(new_server_socket_fd, buffer, sizeof(buffer), 0) < 0)
        {
               printf("Send File:%s Failed./n", file_name);
        }
    bzero(buffer, BUFFER_SIZE); 
        /*/ 開啟檔案並讀取檔案資料
        FILE *fp = fopen(file_name, "r");
        if(NULL == fp)
        {
            printf("File:%s Not Found\n", file_name);
        }
        else
        {
            bzero(buffer, BUFFER_SIZE);
            int length = 0;
            / 每讀取一段資料，便將其傳送給客戶端，迴圈直到檔案讀完為止
            while((length = fread(buffer, sizeof(char), BUFFER_SIZE, fp)) > 0)
            {
                if(send(new_server_socket_fd, buffer, length, 0) < 0)
                {
                    printf("Send File:%s Failed./n", file_name);
                    break;
                }
                bzero(buffer, BUFFER_SIZE);
            }
            / 關閉檔案
            fclose(fp);
            printf("File:%s Transfer Successful!\n", file_name);
        }*/
        // 關閉與客戶端的連線
        close(new_server_socket_fd);
    }
    // 關閉監聽用的socket
    close(server_socket_fd);
    return 0;
}
int CountWordsOfEuropeanTxtFile(char *szFileName)
{
    int nWords = 0;//詞計數變數，初始值為0
    FILE *fp; //檔案指標
    char carrBuffer[1024];//每行字元緩衝，每行最多1024個字元
    //開啟檔案
    if ((fp = fopen(szFileName,  "r")) == NULL)
    {
        return -1;  //檔案開啟不成功是返回-1
    }
    while (!feof(fp))//如果沒有讀到檔案末尾 
    {
        //從檔案中讀一行
        if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
            //統計每行詞數
            nWords += CountWordsInOneLine(carrBuffer);
    }
    //關閉檔案
    fclose(fp);
    return nWords;
}
int CountWordsInOneLine(const char *szLine)
{
    int nWords = 0;
    int i=0;
    for (;i<strlen(szLine);i++)
    {
        if (*(szLine+i)!=' ')
        {
            nWords++;
            while ((*(szLine+i)!=' ')&&(*(szLine+i)!='\0'))
            {
                i++;
            }
        }

    }
            //printf("%d\t",nWords);
    
    return nWords;
}
 

任務二

• 使用多執行緒實現wc伺服器並使用同步互斥機制保證計數正確
  
  

• 伺服器

#include<stdlib.h>
#include<pthread.h>
#include<sys/socket.h>
#include<sys/types.h>     
#include<stdio.h>
#include<netinet/in.h>    
#include<arpa/inet.h>       
#include<assert.h>        
#include<string.h>         
#include<unistd.h>         
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
#define MAX_CONN_LIMIT 512     //MAX connection limit
static void Data_handle(void * sock_fd);   //Only can be seen in the file
int CountWordsOfEuropeanTxtFile(char *szFileName);
int CountWordsInOneLine(const char *szLine);
int main()
{
    int sockfd_server;
    int sockfd;
    int fd_temp;
    struct sockaddr_in s_addr_in;
    struct sockaddr_in s_addr_client;
    int client_length;
    sockfd_server = socket(AF_INET,SOCK_STREAM,0);  //ipv4,TCP
    assert(sockfd_server != -1);
    //before bind(), set the attr of structure sockaddr.
    memset(&s_addr_in,0,sizeof(s_addr_in));
    s_addr_in.sin_family = AF_INET;
    s_addr_in.sin_addr.s_addr = htonl(INADDR_ANY);  //trans addr from uint32_t host byte order to network byte order.
    s_addr_in.sin_port = htons(SOCK_PORT);          //trans port from uint16_t host byte order to network byte order.
    fd_temp = bind(sockfd_server,(const struct sockaddr *)(&s_addr_in),sizeof(s_addr_in));
    if(fd_temp == -1)
    {
        fprintf(stderr,"bind error!\n");
        exit(1);
    }
    fd_temp = listen(sockfd_server,MAX_CONN_LIMIT);
    if(fd_temp == -1)
    {
        fprintf(stderr,"listen error!\n");
        exit(1);
    }
    while(1)
    {
        printf("等待連線...\n");
        pthread_t thread_id;
        client_length = sizeof(s_addr_client);
        //Block here. Until server accpets a new connection.
        sockfd = accept(sockfd_server,(struct sockaddr * restrict)(&s_addr_client),(socklen_t *)(&client_length));
        if(sockfd == -1)
        {
            fprintf(stderr,"Accept error!\n");
            continue;                               //ignore current socket ,continue while loop.
        }
        printf("連線成功!\n");
        if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1)
        {
            fprintf(stderr,"pthread_create error!\n");
            break;                                  //break while loop
        }
    }
    //Clear
    int ret = shutdown(sockfd_server,SHUT_WR); //shut down the all or part of a full-duplex connection.
    assert(ret != -1);
    printf("Server shuts down\n");
    return 0;
}
static void Data_handle(void * sock_fd)
{
    int fd = *((int *)sock_fd);
    int i_recvBytes;
    char data_recv[BUFFER_LENGTH];
    const char * data_send = "伺服器已傳送!\n";
    while(1)
    {
        printf("waiting for file_name...\n");
        //Reset data.
        memset(data_recv,0,BUFFER_LENGTH);
        i_recvBytes = read(fd,data_recv,BUFFER_LENGTH);
        if(i_recvBytes == 0)
        {
            printf("Maybe the client has closed\n");
            break;
        }
        if(i_recvBytes == -1)
        {
            fprintf(stderr,"read error!\n");
            break;
        }
        if(strcmp(data_recv,"quit")==0)
        {
            printf("Quit command!\n");
            break;                           //Break the while loop.
        }
        printf("read from client : %s\n",data_recv);
        
    char buffer[BUFFER_LENGTH];
    int count=0;
    bzero(buffer, BUFFER_LENGTH);
    count = CountWordsOfEuropeanTxtFile(data_recv);
    sprintf(buffer,"%d", count);
        send(fd, buffer, sizeof(buffer), 0);
        if(write(fd,data_send,strlen(data_send)) == -1)
        {
            break;
        }
    }
    //Clear
    printf("terminating current client_connection...\n");
    close(fd);            //close a file descriptor.
    pthread_exit(NULL);   //terminate calling thread!
}
int CountWordsOfEuropeanTxtFile(char *szFileName)
{
    int nWords = 0;//詞計數變數，初始值為0
    FILE *fp; //檔案指標
    char carrBuffer[1024];//每行字元緩衝，每行最多1024個字元
    //開啟檔案
    if ((fp = fopen(szFileName,  "r")) == NULL)
    {
        return -1;  //檔案開啟不成功是返回-1
    }
    while (!feof(fp))//如果沒有讀到檔案末尾 
    {
        //從檔案中讀一行
        if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
            //統計每行詞數
            nWords += CountWordsInOneLine(carrBuffer);
    }

    //關閉檔案
    fclose(fp);
    return nWords;
}
int CountWordsInOneLine(const char *szLine)
{
    int nWords = 0;
    int i=0;
    for (;i<strlen(szLine);i++)
    {
        if (*(szLine+i)!=' ')
        {
            nWords++;
            while ((*(szLine+i)!=' ')&&(*(szLine+i)!='\0'))
            {
                i++;
            }
        }

    }
            //printf("%d\t",nWords);
    
    return nWords;
}
 

• 客戶端

#include<stdlib.h>
#include<sys/socket.h>
#include<sys/types.h>       
#include<stdio.h>
#include<netinet/in.h>      
#include<arpa/inet.h>       
#include<assert.h>          
#include<string.h>        
#include<unistd.h>         
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
int main()
{
    int sockfd;
    int tempfd;
    struct sockaddr_in s_addr_in;
    char data_send[BUFFER_LENGTH];
    char data_recv[BUFFER_LENGTH];
    memset(data_send,0,BUFFER_LENGTH);
    memset(data_recv,0,BUFFER_LENGTH);
    sockfd = socket(AF_INET,SOCK_STREAM,0);       //ipv4,TCP
    if(sockfd == -1)
    {
        fprintf(stderr,"socket error!\n");
        exit(1);
    }
    //before func connect, set the attr of structure sockaddr.
    memset(&s_addr_in,0,sizeof(s_addr_in));
    s_addr_in.sin_addr.s_addr = inet_addr("127.0.0.1");      //trans char * to in_addr_t
    s_addr_in.sin_family = AF_INET;
    s_addr_in.sin_port = htons(SOCK_PORT);
    tempfd = connect(sockfd,(struct sockaddr *)(&s_addr_in),sizeof(s_addr_in));
    if(tempfd == -1)
    {
        fprintf(stderr,"Connect error! \n");
        exit(1);
    }
    while(1)
    {
        printf("請輸入傳送至伺服器的檔案(輸入 \"quit\" 退出):\t");
    scanf("%s", data_send);        
    //gets(data_send);
        //scanf("%[^\n]",data_send);         //or you can also use this
        tempfd = write(sockfd,data_send,BUFFER_LENGTH);
        if(tempfd == -1)
        {
            fprintf(stderr,"write error\n");
            exit(0);
        }

        if(strcmp(data_send,"quit") == 0)  //quit,write the quit request and shutdown client
        {
            break;
        }
        else
        {
            tempfd = read(sockfd,data_recv,BUFFER_LENGTH);
            assert(tempfd != -1);
            printf("%s\n",data_recv);
            memset(data_send,0,BUFFER_LENGTH);
            memset(data_recv,0,BUFFER_LENGTH);
        }
    char buffer[BUFFER_LENGTH];
    int length=0;
    bzero(buffer, BUFFER_LENGTH);
        length = recv(sockfd, buffer, BUFFER_LENGTH, 0);
        buffer[length] = '\0';
        printf("文字檔案單詞數  %s\n", buffer);
        bzero(buffer, BUFFER_LENGTH);
    }
    int ret = shutdown(sockfd,SHUT_WR);       //or you can use func close()--<unistd.h> to close the fd
    assert(ret != -1);
    return 0;
}

• 對比單執行緒版本的效能，並分析原因
  我認為單執行緒的版本效能時間花費比較長，需要一個接一個完成任務，處理效率不高，多執行緒技術可同時處理多個任務，會使程式的響應速度更快一點，提高效率。但是也依舊有缺點，例如使用共享資源時造成程式的執行速度變慢。

實驗中遇到的問題及解決方法

• 問題：在編譯Sever2.c這個檔案時，顯示對‘pthread_create’未定義的引用。

解決辦法：在編譯的結尾新增-lpthread表明需要連結執行緒庫，以便能呼叫標頭檔案pthread.h中的函式。

實驗感想

這次實驗讓我熟悉了WC命令的用法，更加進一步熟悉了用man -k 命令來學習指令的優越性，剛好JAVA WEB課程裡剛好學到了socket程式設計，這讓我在這次試驗裡有了經驗，實驗中的單執行緒與多執行緒知識點讓我在看過書本後有了應用，這次實驗鞏固了我的知識，讓我受益匪淺。