C中的可移植性问题

时间:2012-02-11 18:11:17

标签: c struct portability binaryfiles

我尝试创建一个程序,将 struct elements 写入二进制文件,然后将第一个文件中的唯一元素写入另一个二进制文件。我用 gcc 编译它并且效果非常好,但是当 MinGW 时,程序会在尝试打开并创建第二个文件时冻结。你知道问题出在哪里吗?

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

typedef struct element{
    char name[80];
    int p;
}ELEM;

void clear_stdin()
{
    char str[255];
    fgets(str,255,stdin);
}

int create()
{
    FILE *f;
    int d=0;
    int c;
    int n=0;
    ELEM s;
    f=fopen("file.bin","wb");
    if(f==NULL)
    {
        printf("create(): Could not open file.bin for read\n");
        return;
    }
    do{
    printf("Add elements to file?:\n1 - yes\n2 - no\n");
    scanf("%d",&c);
    if (c==1)
    {
        printf("Name=");
        clear_stdin();
        fgets(s.name,80,stdin);
        printf("P=");
        scanf("%d",&s.p);
        fwrite(&s,sizeof(ELEM),1,f);
        n++;
    }
    else
        d=1;
    } while(d==0);
    fclose(f);
    return n;
}

void show(int n)
{
    FILE *f;
    ELEM s;
    int i=0;
    if(n==0)
        return;
    f=fopen("file.bin","rb");
    while(i<n)
    {
        fread(&s,sizeof(ELEM),1,f);
        puts(s.name);
        printf("\t%d\n",s.p);
        i++;
    }
    fclose(f);
}

int add(int n)
{
    FILE *f;
    int d=0;
    int c;
    ELEM s;
    f=fopen("file.bin","ab");
    if(f==NULL)
    {
        printf("add(): Could not open file.bin for append\n");
        return;
    }
    do{
    printf("Add elements to file?:\n1 - yes\n2 - no\n");
    scanf("%d",&c);
    if (c==1)
    {
        printf("Name=");
        clear_stdin();
        fgets(s.name,80,stdin);
        printf("P=");
        scanf("%d",&s.p);
        fwrite(&s,sizeof(ELEM),1,f);
        n++;
    }
    else
        d=1;
    } while(d==0);
    fclose(f);
    return n;
}


void func(int n)
{
    FILE *f,*g;
    ELEM v[20],w;
    int i=0,j,k,x=0,s,gn=0,test;
    f=fopen("file.bin","rb");
    g=fopen("aux.bin","wb");
    if((g==NULL)||(f==NULL))
    {
        if(g==NULL)
            printf("function() : Could not open aux.bin for write\n");
        if(f==NULL)
            printf("function() : Could not open file.bin for read\n");
        return;
    }
    i=0;
    while(i<n)
    {
        fread(&v[i],sizeof(ELEM),1,f);

        i++;
    }
    for(j=0;j<n;j++)
    {
        for(k=j+1;k<n;k++)
        {
            if(v[j].p==v[k].p)
                x=1;

        }
        if(x==0)
        {
            s=strcmp(v[j].name,v[k].name);
            if(s!=0)
            {
                fwrite(&v[j],sizeof(ELEM),1,g);
                fread(&w,sizeof(ELEM),1,g);

                gn++;
            }
        }
        x=0;
    }
    test=fclose(g);
    if(test!=0)
        printf("function() : failed to closed file g\n");
    test=fclose(f);
    if(test!=0)
        printf("function() : failed to closed file f\n");
    g=fopen("aux.bin","rb");
    if(g==NULL)
    {
        printf("function() : Could not open aux.bin for read\n");
        return;
    }
    if(gn==0)
        return;
    i=0;
    while(i<gn)
    {
        fread(&w,sizeof(ELEM),1,g);
        puts(w.name);
        printf("\t%d\n",w.p);
        i++;
    }
    fclose(g);
}

int main()
{
    int k=0,r,n;
    do{
        printf("1 - create file\n2 - add elements to file\n3 - show elements\n4 - put unique elements in another file\n5 - exit program\n");
        scanf("%d",&r);
        switch(r)
        {
            case 1 : n=create(); break;
            case 2 : n=add(n); break;
            case 3 : show(n); break;
            case 4 : func(n); break;
            case 5 : k=1; break;
            default : printf("Command unrecognized!\n");
        }
    } while(k==0);
    return 0;
}

编辑: 函数 func()是唯一的问题。

编辑:是的我可以在gdb下运行它。

编辑: 在两种情况下,sizeof(ELEM)= 84 offsetof(ELEM,p)= 80。

1 个答案:

答案 0 :(得分:3)

哇,你们不会猜到这一点:aux.bin,实际上任何aux.*都是Windows上的保留文件名!这就是它永远消失的原因!看看这里,所以你不小心选择另一个保留的文件名: windows file name specification(在页面中搜索'aux')