【标准IO】

void save(stu_t* head,const char* filename){
	FILE* fp = fopen(filename,"w");
	stu_t* p = head->next;
	while(p != NULL){
		fwrite(p,sizeof(stu_t),1,fp);
		p = p->next;
	}
	perror("save:");
	fclose(fp);
}

​
void load(stu_t* head,const char* filename){
	FILE* fp = fopen(filename,"rb");
	if(fp == NULL){
		printf("文件不存在\n");
		return;
	}

	 struct Data data = {0};
	while( fread(&data,sizeof(stu_t),1,fp) == 1){

		insert_stu(head,data);
	}
    perror("load:");
	fclose(fp);
}

​

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, const char *argv[])
{
    FILE* fp=fopen("rising_freedom.bmp","r+");
    if(fp == NULL)
    {
        perror("fopen");
        return 1;
    }
    int bmp_size = 0,bmp_width=0,bmp_height= 0;
    fseek(fp,2,SEEK_SET);
    fread(&bmp_size,4,1,fp);
    printf("%d\n",bmp_size);

    fseek(fp,18,SEEK_SET);
    fread(&bmp_width,4,1,fp);
    fread(&bmp_height,4,1,fp);
    printf("%d*%d\n",bmp_width,bmp_height);

    fseek(fp,54,SEEK_SET);
    unsigned char bgr[3]= {0,200,200};
    for(int i=0;i<bmp_width*bmp_height/3;i++)
    {
        fwrite(bgr,3,1,fp);
    }
    fseek(fp,54,SEEK_CUR);
    unsigned char bgr2[3]= {0,0,222};
    for(int i=0;i<bmp_width*bmp_height/3;i++)
    {
        fwrite(bgr2,3,1,fp);
    }
    fseek(fp,54,SEEK_CUR);
    unsigned char bgr3[3]= {0,0,0};
    for(int i=0;i<bmp_width*bmp_height/3;i++)
    {
        fwrite(bgr3,3,1,fp);
    }
    fclose(fp);

    return 0;
}