2017-2018-1 20155328 实验三 实时系统 实验报告
任务一：
1.学习使用Linux命令wc(1)
2.基于Linux Socket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
3.客户端传一个文本文件给服务器
4.服务器返加文本文件中的单词数
-
使用man命令，查看wc：
-
使用wc查看测试文档的单词数：
-
分析wc功能，查看mywc，代码如下：
-
客户端代码如下：
#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
#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()
{
// 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 Server:\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，准备写入
FILE *fp = fopen(file_name, "w");
if(NULL == fp)
{
printf("File:\t%s Can Not Open To Write\n", 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:\t%s Write Failed\n", file_name);
break;
}
bzero(buffer, BUFFER_SIZE);
}
// 接收成功后，关闭文件，关闭socket
printf("Receive File:\t%s From Server IP Successful!\n", file_name);
close(fp);
close(client_socket_fd);
int pid = fork();
char *argv[]={"wc","-w",file_name,0};
execvp( "wc" ,argv);
wait (&pid);
return 0;
}
- 服务器代码如下：
#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 8000
#define LEN 4096
#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\n", 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\n", 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!\n", 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;
}
- 运行截图如下：
任务二：
1.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
2.上方提交代码
3.下方提交测试
4.对比单线程版本的性能，并分析原因
服务器：
#include <stdio.h>
#include <stdlib.h>
#include<pthread.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <dirent.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#define LEN 4096
#define MAXLINE 40
#define BUFFERSIZE 4096
#define PORT 13321
#define BUFFER_LENGTH 1024
#define MAX_CONN_LIMIT 512 //MAX connection limit
ssize_t writen(int fd, const void * vptr, size_t n)
{
size_t nleft;
ssize_t nwritten;
const char * ptr;
ptr = vptr;
nleft = n;
while ( nleft > 0)
{
if ((nwritten = write(fd, ptr, nleft)) <= 0)
{
if (nwritten < 0 && errno == EINTR)
{
nwritten = 0;
}
else
{
return -1;
}
}
nleft -= nwritten;
ptr += nwritten;
}
return n;
}
ssize_t readline(int fd, void * vptr, size_t maxlen)
{
ssize_t n, rc;
char c, *ptr;
ptr = vptr;
for (n = 1; n < maxlen; n++)
{
again:
if ((rc = read(fd, &c, 1)) == 1)
{
*ptr++ = c;
if (c == '\n')
{
break;
}
}
else if (rc == 0)
{
*ptr = 0;
return (n - 1);
}
else
{
if (errno == EINTR)
{
goto again;
}
return (-1);
}
}
*ptr = 0;
return (n);
}
int Socket(int domain, int type, int protocol)
{
int sockfd;
if ((sockfd = socket(domain, type, protocol)) < 0)
{
fprintf(stderr, "socket error\n");
exit(1);
}
return sockfd;
}
int Accept(int sockfd, struct sockaddr * addr, socklen_t * addrlen)
{
int ret;
if ((ret = accept(sockfd, addr, addrlen)) < 0)
{
fprintf(stderr, "accept error\n");
exit(1);
}
return ret;
}
int Bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
{
int ret;
if ((ret = bind(sockfd, addr, addrlen)) < 0)
{
fprintf(stderr, "bind error\n");
exit(1);
}
return ret;
}
int Listen(int sockfd, int backlog)
{
int ret;
if ((ret = listen(sockfd, backlog)) < 0)
{
fprintf(stderr, "listen error\n");
exit(1);
}
return ret;
}
int Close(int fd)
{
int ret;
if ((ret = close(fd)) < 0)
{
fprintf(stderr, "close error\n");
exit(1);
}
return ret;
}
static void Data_handle(void * sock_fd)
{
int fd = *((int *)sock_fd);
int i_recvBytes;
char data_recv[BUFFER_LENGTH];
const char * data_send = "Server has received your request!\n";
pthread_mutex_t counter_mutex = PTHREAD_MUTEX_INITIALIZER;
while(1)
{
pthread_mutex_lock( &counter_mutex );
int totalNum[1] = {0};
FILE *fp; // 指向文件的指针
char buffer[1003]; //缓冲区，存储读取到的每行的内容
int bufferLen; // 缓冲区中实际存储的内容的长度
int i; // 当前读到缓冲区的第i个字符
char c; // 读取到的字符
int isLastBlank = 0; // 上个字符是否是空格
int charNum = 0; // 当前行的字符数
int wordNum = 0; // 当前行的单词数
if( (fp=fopen("/home/rafel/shiyan3/2/save", "rb")) == NULL ){
perror(filename);
exit(1);
}
while(fgets(buffer, 1003, fp) != NULL){
bufferLen = strlen(buffer);
// 遍历缓冲区的内容
for(i=0; i<bufferLen; i++){
c = buffer[i];
if( c==' ' || c=='\t'){ // 遇到空格
!isLastBlank && wordNum++; // 如果上个字符不是空格，那么单词数加1
isLastBlank = 1;
}else if(c!='\n'&&c!='\r'){ // 忽略换行符
charNum++; // 如果既不是换行符也不是空格，字符数加1
isLastBlank = 0;
}
}
!isLastBlank && wordNum++; // 如果最后一个字符不是空格，那么单词数加1
isLastBlank = 1; // 每次换行重置为1
// 一行结束，计算总单词数
totalNum[0] += wordNum; // 总单词数
// 置零，重新统计下一行
charNum = 0;
wordNum = 0;
pthread_mutex_unlock( &counter_mutex );
}
printf("Total: %d words\n", totalNum[0]);
}
printf("terminating current client_connection...\n");
close(fd); //close a file descriptor.
pthread_exit(NULL); //terminate calling thread!
}
int main(void)
{
int listenfd, connfd;
char buff[BUFFERSIZE + 1];
char filename[BUFFERSIZE + 1];
char cd[BUFFERSIZE+1];
char choose[10];
struct sockaddr_in servaddr, cliaddr;
int cliaddrlen;
int filefd;
int count;
DIR *dir;
struct dirent *ptr;
listenfd = Socket(AF_INET, SOCK_STREAM, 0);
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = INADDR_ANY;
servaddr.sin_port = htons(PORT);
Bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
Listen(listenfd, 5);
while(1)
{
printf("开始监听\n");
cliaddrlen = sizeof(cliaddr);
connfd = Accept(listenfd, (struct sockaddr *)&cliaddr, &cliaddrlen);
if (readline(connfd, buff, BUFFERSIZE) < 0)
{
fprintf(stderr, "readline error\n");
exit(1);
}
buff[strlen(buff) - 1] = 0; /* change '\n' to NUL */
memcpy(filename, buff, BUFFERSIZE + 1);
printf("统计的文件名: %s\n", buff);
printf("Input the direct you want to store %s:\n", buff);
scanf("%s", cd);
if(chdir(cd) < 0)
{
fprintf(stderr, "direct error\n");
exit(1);
}
dir = opendir(cd);
while((ptr = readdir(dir)) != NULL)
{
if(strcmp(buff, ptr->d_name) == 0)
{
printf("已存在文件：%s\n", buff);
printf("若想重命名请输入yes,否则请输入no\n");
scanf("%s", choose);
if(strcmp(choose, "yes") == 0)
{
printf("重命名为:\t");
scanf("%s", buff);
}
}
}
filefd = open(buff, O_WRONLY | O_CREAT);
if (filefd < 0)
{
fprintf(stderr, "can't open the file: %s\n", buff);
exit(1);
}
while(count = read(connfd, buff, BUFFERSIZE))
{
if (count < 0)
{
fprintf(stderr, "connfd read error\n");
exit(1);
}
if (writen(filefd, buff, count) < 0)
{
fprintf(stderr, "writing to filefd error\n");
exit(1);
}
}
int sockfd = Accept(listenfd, (struct sockaddr *)&cliaddr, &cliaddrlen);
//sockfd = accept(sockfd_server,(struct sockaddr*)(&s_addr_client),(socklen_t *)(&client_length));
pthread_t thread_id;
if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1)
{
fprintf(stderr,"pthread_create error!\n");
break; //break while loop
}
if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1)
{
fprintf(stderr,"pthread_create error!\n");
break; //break while loop
}
closedir(dir);
Close(filefd);
Close(connfd);
printf("file %s received!\n", filename);
}
}
客户端：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#define MAXLINE 40
#define BUFFERSIZE 4096
#define PORT 13321
ssize_t writen(int fd, const void * vptr, size_t n)
{
size_t nleft;
ssize_t nwritten;
const char * ptr;
ptr = vptr;
nleft = n;
while (nleft > 0)
{
if ((nwritten = write(fd, ptr, nleft)) <= 0)
{
if (nwritten < 0 && errno == EINTR)
{
nwritten = 0;
}
else
{
return -1;
}
}
nleft -= nwritten;
ptr += nwritten;
}
return n;
}
int Socket(int domain, int type, int protocol)
{
int sockfd;
if ((sockfd = socket(domain, type, protocol)) < 0)
{
fprintf(stderr, "socket error\n");
exit(1);
}
return sockfd;
}
int Connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
{
int ret;
if ((ret = connect(sockfd, addr, addrlen)) < 0)
{
fprintf(stderr, "connect error\n");
exit(1);
}
return ret;
}
int Close(int fd)
{
int ret;
if ((ret = close(fd)) < 0)
{
fprintf(stderr, "close error\n");
exit(1);
}
return ret;
}
int main(int argc, char *argv[])
{
if (argc != 3)
{
fprintf(stderr, "Usage: ./fileclient <file> <serverIP>\n");
exit(1);
}
int sockfd;
char buff[BUFFERSIZE + 1];
char filenameheader[BUFFERSIZE + 1];
struct sockaddr_in servaddr;
int filefd; /* file descriptor */
int count;
sockfd = Socket(AF_INET, SOCK_STREAM, 0);
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr=INADDR_ANY;
servaddr.sin_port = htons(PORT);
Connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
printf("已连接服务器\n");
printf("需统计的文件名为: %s........\n", argv[1]);
memcpy(filenameheader, argv[1], strlen(argv[1]));
filenameheader[strlen(argv[1])] = '\n';
filenameheader[strlen(argv[1]) + 1] = 0;
writen(sockfd, filenameheader, strlen(filenameheader));
printf("正上传文件%s至服务器\n", argv[1]);
filefd = open(argv[1], O_RDONLY);
if (filefd < 0)
{
fprintf(stderr, "can't open the file: %s\n", argv[1]);
exit(1);
}
while(count = read(filefd, buff, BUFFERSIZE))
{
if (count < 0)
{
fprintf(stderr, "filefd read error\n");
exit(1);
}
if (writen(sockfd, buff, count) < 0)
{
fprintf(stderr, "writing to sockfd error\n");
exit(1);
}
}
Close(filefd);
Close(sockfd);
printf("文件%s已上传至服务器!\n", argv[1]);
return 0;
}
客户端：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#define MAXLINE 40
#define BUFFERSIZE 4096
#define PORT 13321
ssize_t writen(int fd, const void * vptr, size_t n)
{
size_t nleft;
ssize_t nwritten;
const char * ptr;
ptr = vptr;
nleft = n;
while (nleft > 0)
{
if ((nwritten = write(fd, ptr, nleft)) <= 0)
{
if (nwritten < 0 && errno == EINTR)
{
nwritten = 0;
}
else
{
return -1;
}
}
nleft -= nwritten;
ptr += nwritten;
}
return n;
}
int Socket(int domain, int type, int protocol)
{
int sockfd;
if ((sockfd = socket(domain, type, protocol)) < 0)
{
fprintf(stderr, "socket error\n");
exit(1);
}
return sockfd;
}
int Connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
{
int ret;
if ((ret = connect(sockfd, addr, addrlen)) < 0)
{
fprintf(stderr, "connect error\n");
exit(1);
}
return ret;
}
int Close(int fd)
{
int ret;
if ((ret = close(fd)) < 0)
{
fprintf(stderr, "close error\n");
exit(1);
}
return ret;
}
int main(int argc, char *argv[])
{
if (argc != 3)
{
fprintf(stderr, "Usage: ./fileclient <file> <serverIP>\n");
exit(1);
}
int sockfd;
char buff[BUFFERSIZE + 1];
char filenameheader[BUFFERSIZE + 1];
struct sockaddr_in servaddr;
int filefd; /* file descriptor */
int count;
sockfd = Socket(AF_INET, SOCK_STREAM, 0);
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr=INADDR_ANY;
servaddr.sin_port = htons(PORT);
Connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
printf("已连接服务器\n");
printf("需统计的文件名为: %s........\n", argv[1]);
memcpy(filenameheader, argv[1], strlen(argv[1]));
filenameheader[strlen(argv[1])] = '\n';
filenameheader[strlen(argv[1]) + 1] = 0;
writen(sockfd, filenameheader, strlen(filenameheader));
printf("正上传文件%s至服务器\n", argv[1]);
filefd = open(argv[1], O_RDONLY);
if (filefd < 0)
{
fprintf(stderr, "can't open the file: %s\n", argv[1]);
exit(1);
}
while(count = read(filefd, buff, BUFFERSIZE))
{
if (count < 0)
{
fprintf(stderr, "filefd read error\n");
exit(1);
}
if (writen(sockfd, buff, count) < 0)
{
fprintf(stderr, "writing to sockfd error\n");
exit(1);
}
}
Close(filefd);
Close(sockfd);
printf("文件%s已上传至服务器!\n", argv[1]);
return 0;
}
客户端：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#define MAXLINE 40
#define BUFFERSIZE 4096
#define PORT 13321
ssize_t writen(int fd, const void * vptr, size_t n)
{
size_t nleft;
ssize_t nwritten;
const char * ptr;
ptr = vptr;
nleft = n;
while (nleft > 0)
{
if ((nwritten = write(fd, ptr, nleft)) <= 0)
{
if (nwritten < 0 && errno == EINTR)
{
nwritten = 0;
}
else
{
return -1;
}
}
nleft -= nwritten;
ptr += nwritten;
}
return n;
}
int Socket(int domain, int type, int protocol)
{
int sockfd;
if ((sockfd = socket(domain, type, protocol)) < 0)
{
fprintf(stderr, "socket error\n");
exit(1);
}
return sockfd;
}
int Connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
{
int ret;
if ((ret = connect(sockfd, addr, addrlen)) < 0)
{
fprintf(stderr, "connect error\n");
exit(1);
}
return ret;
}
int Close(int fd)
{
int ret;
if ((ret = close(fd)) < 0)
{
fprintf(stderr, "close error\n");
exit(1);
}
return ret;
}
int main(int argc, char *argv[])
{
if (argc != 3)
{
fprintf(stderr, "Usage: ./fileclient <file> <serverIP>\n");
exit(1);
}
int sockfd;
char buff[BUFFERSIZE + 1];
char filenameheader[BUFFERSIZE + 1];
struct sockaddr_in servaddr;
int filefd; /* file descriptor */
int count;
sockfd = Socket(AF_INET, SOCK_STREAM, 0);
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr=INADDR_ANY;
servaddr.sin_port = htons(PORT);
Connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
printf("已连接服务器\n");
printf("需统计的文件名为: %s........\n", argv[1]);
memcpy(filenameheader, argv[1], strlen(argv[1]));
filenameheader[strlen(argv[1])] = '\n';
filenameheader[strlen(argv[1]) + 1] = 0;
writen(sockfd, filenameheader, strlen(filenameheader));
printf("正上传文件%s至服务器\n", argv[1]);
filefd = open(argv[1], O_RDONLY);
if (filefd < 0)
{
fprintf(stderr, "can't open the file: %s\n", argv[1]);
exit(1);
}
while(count = read(filefd, buff, BUFFERSIZE))
{
if (count < 0)
{
fprintf(stderr, "filefd read error\n");
exit(1);
}
if (writen(sockfd, buff, count) < 0)
{
fprintf(stderr, "writing to sockfd error\n");
exit(1);
}
}
Close(filefd);
Close(sockfd);
printf("文件%s已上传至服务器!\n", argv[1]);
return 0;
}
运行截图如下：
