c - 如何从fscanf循环中存在？

Question

当没有更多数据可供读取时，我希望从循环中存在。 我曾尝试过 !feof(fp), EOF，但它无限循环。 如果我更改为 fscanf(fp, str, &str) == 1，它无法读取任何内容。 这是代码:

void readFile(){

    FILE *fp;   
    int i=0, j=1;   
    int* arr;
    char str[45];


    fp = fopen("c:\\Defuzzification.txt","r"); // read mode

    if (fp == NULL) {       
        perror("Error while opening the file.\n");
        exit(EXIT_FAILURE);
    }



    arr = (int*)calloc(SIZE, sizeof(int));

    while( fscanf(fp, "The different between frame %d and %d :%d",  &i, &j, arr)  == 1 ){
        fscanf(fp, "The different between frame %d and %d :%d",  &i, &j, arr);
        printf("Display The different between frame %d and %d :%d\n",  i, j, *arr);
        i++;
        j++;    
    }

    fclose(fp); 
}

while(fscanf(fp, "帧 %d 和 %d 之间的差异:%d", &i, &j, arr) != EOF) =>> 无限循环

while( fscanf(fp, "帧 %d 和 %d :%d 之间的差异", &i, &j, arr) == 1 ) =>> 不读取内容

输入数据:

The different between frame 0 and 1 :80
The different between frame 1 and 2 :58.18
The different between frame 2 and 3 :77.59
The different between frame 3 and 4 :71.24
The different between frame 4 and 5 :68.46
The different between frame 5 and 6 :75.81
The different between frame 6 and 7 :41.35

Answer 1

在下面的语句中，如果所有输入操作都成功，fscanf将返回3。

while( fscanf(fp, "The different between frame %d and %d :%d",  &i, &j, arr)  == 1 ){

将其更改为:

while( fscanf(fp, "The different between frame %d and %d :%d",  &i, &j, arr)  == 3 ){

另一件事...你有数字80、58.18等。这些是 float 而不是整数。您不应该使用浮点格式并将其读取到浮点变量吗？

float number;
while( fscanf(fp, "The different between frame %d and %d :%f",  &i, &j, &number)  == 3 ){

更新

您需要进行以下更改:

1. 在 fscaf 的格式字符串中，放置一个空格作为第一个字符。这将跳过零个或多个空格，包括换行符。

2. 使用 float 读取最后的数据。否则，数字的小数部分会留在输入流中，并且后续读取操作将失败。

3. 您需要将while语句的条件中fscanf的返回值与3进行比较。如果fscanf能够成功读取全部三段数据，将返回3。

使用以下代码块读取数据对我有用:

float number;
while( fscanf(fp, " The different between frame %d and %d :%f",  &i, &j, &number)  == 3 ){
    fscanf(fp, " The different between frame %d and %d :%f",  &i, &j, &number);
    printf("Display The different between frame %d and %d :%f\n",  i, j, number);
    i++;
    j++;    
}