2023.12.29 作业

思维导图

练习题

1> 使用fgets统计一个文件的行号

#include 
#include 
#include 

int main(int argc, const char *argv[])
{
	FILE *file;
	char line[1024];
	int count=0;

	file=fopen("test.txt","r");
	if(file==NULL)
	{
		perror("无法打开文件");
		return -1;
	}

	while(fgets(line,sizeof(line),file)!=NULL)
	{
		count++;
	}

	fclose(file);
	printf("文件有 %d 行\n",count);

	return 0;
}

2> 使用fgets、fputs完成两个文件的拷贝

#include 
#include 
#include 

int main(int argc, const char *argv[])
{
	FILE *file,*file1;
	char buffer[1024]="";
	
	if(argc!=3)
	{
		return -1;
	}

	file=fopen(argv[1],"r");
	if(file==NULL)
	{
		perror("未找到文件");
		fclose(file);
		return -1;
	}
	file1=fopen(argv[2],"w");
	if(file1==NULL)
	{
		perror("打开文件失败");
		fclose(file1);
		return -1;
	}

	while(fgets(buffer,sizeof(buffer),file)!=NULL)
	{
		fputs(buffer,file1);
	}
	puts("文件拷贝成功");
	fclose(file);
	fclose(file1);
	return 0;
}

3> 向文件中输出当前的系统时间

#include 
#include 
#include 
#include 
#include 

int main(int argc, const char *argv[])
{
	FILE *file;
	int count=0;
	file=fopen("time.txt","a");
	if(file==NULL)
	{
		perror("未找到文件");
		return -1;
	}
	FILE *lineNumberFile=fopen("time.txt","r");
	int lineNumber=0;
	char line[1024]="";
	while(fgets(line,sizeof(line),lineNumberFile)!=NULL)
	{
		lineNumber++;
	}
	fclose(lineNumberFile);
	printf("lineNumber=%d\n",lineNumber);
	while(1)
	{
		count++;
		time_t sys_time=0;
		time(&sys_time);
		struct tm *t=localtime(&sys_time);
		char timeString[100]="";
		sprintf(timeString,"%d: %4d-%2d-%2d %2d:%2d:%2d\n",lineNumber+count,t->tm_year+1900,\
				t->tm_mon+1,t->tm_mday,t->tm_hour,t->tm_min,t->tm_sec);
		printf("%s\n",timeString);
		
		fputs(timeString,file);
		fflush(file);

		sleep(1);
	}


	fclose(file);

	return 0;
}