11.05 标准IO +作业

IO理解：

#include <myhead.h>
int main(int argc, const char *argv[])
{
	FILE *fp;
	fp = fopen("./7.txt","w");
	if(fp==NULL)
	{
		perror("fp");
		return -1;
	}
	fputc('A',fp);
	fputc('\n',fp);
	int m = 'M';
	fputc(m,fp);
	fputc('B',fp);
	fputc('\n',fp);
	fputc('C',fp);
	fputc('\n',fp);
	fputc('D',fp);
	fputc('\n',fp);
	fputc('e',fp);
	fputc('\n',fp);

	fclose(fp);

	fp = fopen("./7.txt","r");

	int n,count = 0;
	while((n = fgetc(fp))!=EOF)
	{
		printf("%c",n);
		if(n==10)
		{
			count++;
		}
	}
	printf("文件有%d行",count);

	return 0;
}