IO 作业 24/2/19

1> 使用fread和fwrite完成两个文件的拷贝

#include <myhead.h>
int main(int argc, const char *argv[])
{
	//定义被复制文件指针
	FILE *fp1=NULL;
	if((fp1=fopen("./111.bmp","r"))==NULL)
	{
		perror("error open");
		return -1;
	}
	//定义目标文件指针
	FILE *fp2=NULL;
	if((fp2=fopen("./333.bmp","w+"))==NULL)
	{
		perror("error open");
		return -1;
	}
	//定义字符串数组存储读取的数据
	char str[1024]="";
	int res=0;
	while((res=fread(str,1,sizeof(str),fp1))>0)
	{
		fwrite(str,1,res,fp2);
	}
	fclose(fp1);
	fclose(fp2);
	return 0;
}

2> 使用read、write完成两个文件的拷贝

#include <myhead.h>
int main(int argc, const char *argv[])
{
	//定义被复制文件标识符
	int fd1=-1;
	if((fd1=open("./111.bmp",O_RDONLY))==-1)
	{
		perror("open error");
		return -1;
	}
	//定义目标文件标识符
	int fd2=-1;
	if((fd2=open("./222.bmp",O_RDWR|O_CREAT|O_TRUNC,0664))==-1)
	{
		perror("open error");
		return -1;
	}
	//定义数组存储读取的数据
	char str[1024]="";
	int t;
	while((t=read(fd1,str,sizeof(str)))>0)
	{
		write(fd2,str,t);//向目标文件写入
	}
	//关闭文件
	close(fd1);
	close(fd2);
	return 0;
}

3> 将时间在文件中跑起来

#include <myhead.h>
int main(int argc, const char *argv[])
{
	FILE *fp=NULL;
	if((fp=fopen("./Time.txt","w+"))==NULL)
	{
		perror("open error");
		return -1;
	}
	int n=1；
	char T[1024]="";
	char Tr[1024]="";
	
	while(1)
	{
		sleep(1);
		time_t sysTime=time(NULL);
		struct tm *t=localtime(&sysTime);
		fseek(fp,0,SEEK_SET);
		snprintf(T,sizeof(T),"%d:%d-%d-%d %d:%d:%d\n",n,t->tm_year+1900,t->tm_mon+1,t->tm_mday,t->tm_hour,t->tm_min,t->tm_sec);	
		fwrite(T,strlen(T),1,fp);
		fseek(fp,0,SEEK_SET);
		fread(Tr,strlen(T),1,fp);
		printf("%s",Tr);
		n++;
	}
	fclose(fp);
	return 0;
}