c - 删除记录二进制文件c

Question

我刚刚编写了一个从二进制文件中删除记录的程序，但问题是即使程序找到了与该名称匹配的项，当我将记录写入临时文件时，它实际上并没有从文件中删除它文件。我在 else 条件下可能会出错吗？

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct {
    int dd;
    int mm;
    int yyyy;
}date;

struct _food
{
    char category[20];
    char name[30];
    int amount;
    data expiry;
    int calories;
} food;
int main()
{
    FILE* fba;
    FILE* temp;
    int found = 0;
    char nome_t[30];
    char newname[] = "alimenti.bin";
    char oldname[] = "temp.bin";
    fba = fopen("alimenti.bin", "rb");
    temp = fopen("temp.bin", "wb");

    printf("Type the name of the food you want to delete:\n");
    gets(nome_t);
    while(fread(&food,sizeof(food),1,fba))
    {
        if(strcmp(nome_t,food.name) != 0)   
        {
            fwrite(&food,sizeof(food),1,temp);

        }
        else{
            found = 1;
            printf("Match found. Food deleted.\n");

        }

    }
    if (!found){
        printf("No match.\n");

    }

    fclose(fba);
    fclose(temp);
    remove(oldname);
    rename(oldname,newname);
    system("PAUSE");
    return 0;


}

Answer 1

您正在删除更新的文件(temp.bin，又名 oldname):

remove(oldname);

在您尝试用它替换原始文件(alimenti.bin，又名 newname)之前:

rename(oldname,newname);

你的意思是:

remove(newname);