将 *.data 文件读入动态扩展的 struct 数组中***

Question

我是 C 编程的新手，我想将 *.data 文件读入动态扩展的结构数组中。完成后，我想按值排序并按高/低顺序打印。我已经能够完成排序和打印功能，但不能完成文件的阅读。 我经历了几个例子，但无法理解。任何帮助，将不胜感激。谢谢

文件中的示例数据

alpha 4.8 28000 白色

delta 1.2 321 橙色

struct dataBase
{
    char modelName[31];
    float capacity;
    int mileage;
    char color[15];
};

int main (void)
{

readData();

// set up conditions for the loop

int choice;
choice = 0;

// I used a do while loop to insure that it would run once
do{
    // print menu
    printf ( "Make your choice.\n");
    printf ( "1. Sort data by the float value & print high to low.\n" );
    printf ( "2. Sort data by the float value & print low to high.\n" );
    printf ( "3. Sort data by the int value & print high to low.\n" );
    printf ( "4. Sort data by the int value & print low to high.\n");
    printf ( "5. Exit.\n\n");

    // get user input and clear out stdin
    choice = getchar();
    // this part clears the stdin of leftovers
    while ( getchar() != '\n' ) ;

    // Call the desired function
    if (choice == '1' ) {
        compareFloat();
        printHigh(Input_Size);
    }
    else if (choice == '2' ) {
        compareFloat();
        printLow(Input_Size);
    }
    else if (choice == '3' ) {
        compareInt();
        printHigh(Input_Size);
    }
    else if (choice == '4') {
        compareInt(Input_Size);
    }
}
// Check for escape code
while ( choice != '5');

// just to verify I finished
printf ( "Done\n");

return 0;         
}

int compareFloat(const void *s1, const void *s2)
{
  struct dataBase *e1 = (struct dataBase *)s1;
  struct dataBase *e2 = (struct dataBase *)s2;
  if (e1->capacity < e2->capacity)
    return -1;
  else if (e1->capacity > e2->capacity)
    return +1;
  else
    return 0;
}

void printLow(int size)
{
    for(int i=0; i<size; i++)
    {
        printf(dataBase[i].modelName + " " + dataBase[i].capacity + " " + 
               dataBase[i].mileage + " " + dataBase[i].color);
    }
}

void readData(void)
{
    FILE *inputFile
    inputFile = fopen("file.data", 'rb');
}

Answer 1

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

struct dataBase
{
    char modelName[31];
    float capacity;
    int mileage;
    char color[15];
};

struct dataBase *Inputs      = NULL;
size_t           Inputs_Size = 0;
size_t           Num_Inputs  = 0;

void printLow(int size)
{
    int i;
    for(i=0; i<size; i++)
    {
        printf("%s %f %d %s\n", Inputs[i].modelName, Inputs[i].capacity, Inputs[i].mileage, Inputs[i].color);
    }
}

void readData(void)
{
    FILE *inputFile;
    struct dataBase input;

    if (NULL == (inputFile = fopen("file.data", "r")))
    {
        perror("Couldn't open file.data!");
        return;
    }

    while (4 == fscanf(inputFile, "%30s %f %d %14s", input.modelName, &input.capacity, &input.mileage, input.color))
    {
        if (++Num_Inputs > Inputs_Size)
        {
            size_t new_size = 2 * Num_Inputs;
            struct dataBase *new_inputs = realloc(Inputs, new_size * sizeof(struct dataBase));

            if (NULL == new_inputs)
            {
                perror("realloc failed!");
                goto FAIL_INPUTFILE;
            }

            Inputs      = new_inputs;
            Inputs_Size = new_size;
       }

       Inputs[Num_Inputs - 1] = input;
       printf("'%s' %f %d '%s'\n", input.modelName, input.capacity, input.mileage, input.color);
    }

    if (!feof(inputFile))
    {
        fprintf(stderr, "Malformed line didn't match expected input format!\n");
    }

FAIL_INPUTFILE:    
    fclose(inputFile);
}

int main()
{
  readData();

  return 0;
}