C语言超详细文件操作基础下篇

#include<stdio.h>
struct S
{
	char arr[10];
	int num;
	float sc;
};
int main()
{
	struct S s = { "abcdef",20,5.5f };
	FILE* pf = fopen("test.dayta", "w");
	if (NULL == pf)
	{
		return 1;
	}
	//写文件
	fprintf(pf, "%s %d %f", s.arr, s.num, s.sc);//这就是如何把格式化的数据写到文件里
	//关闭文件
	fclose(pf);
	pf = NULL;
	return 0;
 
}

#include<stdio.h>
struct S
{
	char arr[10];
	int num;
	float sc;
};
int main()
{
	struct S s = {0};
	FILE* pf = fopen("test.dayta", "r");
	if (NULL == pf)
	{
		return 1;
	}
	//写文件
	fscanf(pf, "%s %d %f", s.arr, &(s.num), &(s.sc));//这就是如何把格式化的数据写到文件里
	printf("%s %d %f", s.arr, s.num, s.sc);
	fprintf(stdout, "%s %d %f", s.arr, s.num, s.sc);//这类函数参数不同，功能就不同，可以适用于所有的流
	//关闭文件
	fclose(pf);
	pf = NULL;
	return 0;
 
}

struct S
{
    char arr[10];
    int num;
    float sc;
};
int main()
{
    struct S s = {"abcdef",20,5.5f};
    FILE* pf = fopen("test.dayta", "w");
    if (NULL == pf)
    {
        return 1;
    }
    //写文件
    fwrite(&s, sizeof(struct S), 1, pf);
    //关闭文件
    fclose(pf);
    pf = NULL;
    return 0;
 
}

#include<stdio.h>
struct S
{
	char arr[10];
	int num;
	float sc;
};
int main()
{
	struct S s = {0};
	FILE* pf = fopen("test.dayta", "r");
	if (NULL == pf)
	{
		return 1;
	}
	//写文件
	fread(&s, sizeof(struct S), 1, pf);
	printf("%s %d %f", s.arr, &(s.num), &(s.sc));
	//关闭文件
	fclose(pf);
	pf = NULL;
	return 0;
 
}

#include<stdio.h>
int main()
{
	
	FILE* pf = fopen("test.data", "r");
	if (NULL == pf)
	{
		perror("main");
		return 1;
	}
	//读取文件
	int ch = fgetc(pf);
	printf("%c\n", ch);
	//调整文件
 
	fseek(pf, 2, SEEK_END);
	int ch = fgetc(pf);
	printf("%c\n", ch);
 
	//关闭文件
	fclose(pf);
	pf = NULL;
	return 0;
 
}

#include<stdio.h>
int main()
{
	FILE* pfread = fopen("test.txt", "r");
	if (NULL == pfread)
	{
		return 1;
	}
	FILE* pfwrite = fopen("test2.txt", "w");
	{
		if (pfread == NULL)
		{
			fclose(pfread);
			pfread = NULL;
				return 1;
		}
		//文件打开成功
		//读写文件
		int ch = 0;
		while((ch = fgetc(pfread))!= EOF)
		{
			//写文件
			fputc(ch, pfwrite);
		}
	}
	//关闭文件
	fclose(pfwrite);
	pfwrite = NULL;
	return 0;
}