c - 结构和文件处理

Question

我正在编写的程序必须将文本文件中的值存储在各自的变量上。问题似乎出现在内部循环中。我已经定义了各自的结构。程序在外循环中正常运行，但当它在内循环中继续时，文件指针不会从文本文件中读取正确的值并输出“0.0”，并且不会完全继续外循环中的处理。

我的输入文件看起来像这样:

GENERAL
1   4

PANELS
1   2.1 3.1 4.1 5.1 6.1 7.1 1
2   2.2 3.2 4.2 5.2 6.2 7.2 2
    1   2.21    3.21    4.21    5.21
    2   2.22    3.22    4.22    5.22
3   2.3 3.3 4.3 5.3 6.3 7.3 0
4   2.4 3.4 4.4 5.4 6.4 7.4 4
    1   2.41    3.41    4.41    5.41
    2   2.42    3.42    4.42    5.42
    3   2.43    3.43    4.43    5.43
    4   2.44    3.44    4.44    5.44

MATERIAL
1   1000.0  2000.0  3000.0  4000.0
2   1010.0  2020.0  3030.0
3   1010.1  2020.2

CHB
1   10  20  30  2
2   11  22  33  1

这些只是占位符，用于查看它们是否已存储。个位数是整数，而 float 有小数点。

这是代码

typedef struct _open
{
    int id;
    double length;
    double height;
    double origX;
    double origY;
    int frames;

    double thickness;
    double E;
    double v;
}CHBOpening;

typedef struct _panels
{
    int id;
    double length;
    double height;
    double origX;
    double origY;
    double origZ;
    double angle;
    int nOpenings;
    int nReinforcement;
    double *xReinf;
    double sx;
    double xReinf0;

    CHBUnit *chb;
    CHBOpening *openings[];
}CHBPanel;

typedef struct _chb
{
    int nStories;
    int nModes;
    int nIter;
    int nPanels;
    CHBPanel *panels[];
}CHBStructure;
int ReadPanelBlock (FILE *fp, CHBStructure *S)
{
    int i,j;
    S->panels = malloc(S->nPanels*sizeof(CHBStructure));
    for (i=0; i< S->nPanels; i++)
    {
        fscanf(fp,"%d",&S->panels[i].id);
        fscanf(fp,"%lf",&S->panels[i].length);
        fscanf(fp,"%lf",&S->panels[i].height);
        fscanf(fp,"%lf",&S->panels[i].angle);
        fscanf(fp,"%lf",&S->panels[i].origX);
        fscanf(fp,"%lf",&S->panels[i].origY);
        fscanf(fp,"%lf",&S->panels[i].origZ);
        fscanf(fp,"%d",&S->panels[i].nOpenings);
        if (S->panels[i].nOpenings > 0)
        {
            S->panels[i].openings = malloc(sizeof(CHBOpening)*S->panels[i].nOpenings);

            for (j=0; j<S->panels[i].nOpenings;j++)
            {
                fscanf(fp,"%d",&S->panels[i].openings[j].id);
                fscanf(fp,"%lf",&S->panels[i].openings[j].length);
                fscanf(fp,"%lf",&S->panels[i].openings[j].height);
                fscanf(fp,"%lf",&S->panels[i].openings[j].origX);
                fscanf(fp,"%lf",&S->panels[i].openings[j].origY);
            }
        }
    }
    return 1;
}

Answer 1

当您分配pannels时你会的

S->panels = malloc(S->nPanels*sizeof(CHBStructure));

这里的问题是您使用 sizeof(CHBStructure)而不是sizeof(CHBPanel) 。问题在于sizeof(CHBStructure) < sizeof(CHBPanel) ，因此您没有为读取的数据分配足够的内存。

这将导致写入越界和未定义的行为。

这是输入文件中“拼写错误”的 补充，这将导致您在没有任何内容可读取时进入内部循环。