实验任务
任务一
- 学习使用Linux命令wc(1)
在终端中输入
man 1 wc
查看man手册对wc的解释：
【man 1 wc】
- 基于LinuxSocket程序设计实现wc（1）服务器(端口号是你学号的后6位)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
客户端代码实现：
#include<netinet/in.h> // sockaddr_in
#include<sys/types.h>
#include<sys/socket.h>
#include<stdio.h>
#include<string.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>
#define LEN 4096
#define SERVER_PORT 8000
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int main()
{
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，返回socket描述符
int client_socket_fd = socket(AF_INET, SOCK_STREAM, 0);
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);
// connet
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("请输入文件名 :");
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));
// send
if(send(client_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
{
perror("Send File Name Failed:");
exit(1);
}
// 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);
}
// 从服务器接收数据到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(client_socket_fd, buffer, BUFFER_SIZE, 0)) > 0)
{
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("已成功接受文件: %s
", file_name);
close(fp);
close(client_socket_fd);
char *argv[]={"wc","-w",file_name,0};
execvp( "wc" ,argv);
return 0;
}
服务器代码：
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h> // socket
#include<stdio.h>
#include<string.h> // bzero
#define SERVER_PORT 8000
#define LEN 4096
#define LENGTH_OF_LISTEN_QUEUE 20
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int main()
{
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);
int opt = 1;
setsockopt(server_socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
// bind
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，便将其发送给客户端，循环直到文件读完为止
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);
}
// 关闭文件
fclose(fp);
// printf("File:%s Transfer Successful!
", file_name);
}
// 关闭与客户端的连接
close(new_server_socket_fd);
}
// 关闭监听用的socket
close(server_socket_fd);
return 0;
}
程序截图：
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
多线程服务器：
#include "csapp.h"
void echo(int connfd);
void *thread(void *vargp);
int main(int argc, char **argv)
{
int listenfd, *connfdp, port, clientlen=sizeof(struct sockaddr_in);
struct sockaddr_in clientaddr;
pthread_t tid;
if (argc != 2) {
fprintf(stderr, "usage: %s <port>
", argv[0]);
exit(0);
}
port = atoi(argv[1]);
listenfd = Open_listenfd(port);
while (1) {
connfdp = Malloc(sizeof(int));
*connfdp = Accept(listenfd, (SA *) &clientaddr, &clientlen);
Pthread_create(&tid, NULL, thread, connfdp);
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，便将其发送给客户端，循环直到文件读完为止
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);
}
// 关闭文件
fclose(fp);
}
}
void *thread(void *vargp)
{
int connfd = *((int *)vargp);
Pthread_detach(pthread_self());
Free(vargp);
Close(connfd);
return NULL;
}
程序运行结果：
多线程处理的优缺点：
同步应用程序的开发比较容易，但由于需要在上一个任务完成后才能开始新的任务，其效率通常比多线程应用程序低。如果完成同步任务所用的时间比预计时间长，应用程序可能会不响应。