缓冲区的思维模式==fflush

 

#include<stdio.h>

#include<stdlib.h>

void main(){

FILE*read = fopen("1.txt","w");

if (!read) {

printf("文件为空");

system("pause");

return;

}

fputs("你好a\n", read);

fflush(read);

fputs("你好b\n", read);

fputs("你好c\n", read);

fclose(read);

system("pause");

 

}

缓存区的目的就是为了解决性能问题,提高程序运行效率.

---

生成大文件.

 

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

void main() {

FILE*read = fopen("D:/1/1.txt", "wb");

if (!read) {

printf("文件为空");

system("pause");

return;

}

fseek(read, 6, SEEK_SET);

fputc('\0', read);

fclose(read);

 

system("pause");

}

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

void main() {

for (size_t i = 0; i < 5; i++)

{

char out[50] = { 0 };

sprintf(out, "D:/1/%d.txt", i);

FILE*read = fopen(out, "wb");

if (!read) {

printf("文件为空");

system("pause");

continue;

}

fseek(read, 6, SEEK_SET);

fputc('\0', read);

fclose(read);

}

system("pause");

}

 

---

通过ftell函数,获取文件大小.

 

#include<stdlib.h>

#include<stdio.h>

#include<string.h>

void main() {

 

 

 

FILE*read = fopen("D:/1/1.txt", "rb");

if (!read) {

printf("文件为空");

system("pause");

return;

}

fseek(read, 0, SEEK_END);

int count = ftell(read);

fclose(read);

printf("文件大小为:%d\n", count);

 

system("pause");

}