在C中从字符串转换为整数时发生内存泄漏（？）

Question

so i wrote this program which reads two lines of text from a text file called "input.txt" (it has two lines, a number on each) then convert both numbers to integers in two different arrays. 因此，我编写了此程序，该程序从名为“ input.txt”的文本文件中读取两行文本（它有两行，每行一个数字），然后将两个数字转换为两个不同数组中的整数。 for integer arrays i used malloc and realloc to dynamically allocate memory. 对于整数数组，我使用malloc和realloc动态分配内存。 as you can see in the picture below it works fine for second number, but the first number is just some random numbers (changes each time). 如您在下面的图片中所见，它对于第二个数字很好用，但是第一个数字只是一些随机数（每次都会更改）。 why is this happening? 为什么会这样呢？

(I'm using codeblocks.) （我正在使用代码块。）

在此处输入图片说明

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#define SIZE_MAX 10
#define SIZE_USE (SIZE_MAX-1)

int input(char num_first[], char num_second[]);
int convert(int iinum_first[], int iinum_second[], char num_first[], char num_second[], int firstlen, int secondlen, int c, int c2);

int main()
{

    char num_first[SIZE_MAX]; // original input as string
    char num_second[SIZE_MAX];

    input(num_first, num_second);

    int firstlen = strlen(num_first)-1;
    int secondlen = strlen(num_second);

    int i, c=0, c2=0;
    for (i = 0; i <= firstlen; i++)
    {
        c++; // counts number of elements needed to resize array
    }
    for (i = 0; i <= secondlen; i++)
    {
        c2++;
    }

    int *iinum_first = NULL; // converted integer input
    int *iinum_second = NULL;

    iinum_first = (int*)malloc(sizeof(int));
    iinum_second = (int*)malloc(sizeof(int));


    convert(iinum_first, iinum_second, num_first, num_second, firstlen, secondlen, c, c2);

    printf("first integer: ");
    for (i = 0; i < firstlen; i++) // print first integer
    {
        printf("%d", iinum_first[i]);
    }
    printf("\nsecond integer: ");
    for (i = 0; i < secondlen; i++) // print second integer
    {
        printf("%d", iinum_second[i]);
    }
    puts("");

    return 0;
}

int input(char num_first[], char num_second[])
{
    FILE *fPTR;
    int i;

    if ((fPTR = fopen("input.txt", "r")) == NULL)
    {
        puts(":( File could not be opened.");
    }
    else
    {
        if (fgets(num_first, SIZE_MAX, fPTR) != NULL)
            printf("first string: "); // print string input
        puts(num_first);
        if (fgets(num_second, SIZE_MAX, fPTR) != NULL)
            printf("second string: ");
        puts(num_second);
        fclose(fPTR);
    }

    return 0;
}

int convert(int iinum_first[], int iinum_second[], char num_first[], char num_second[], int firstlen, int secondlen, int c, int c2)
{
    // dynamic memory allocation

    int i;

    int *temp = NULL;
    int *temp2 = NULL;

    temp = (int*)realloc(iinum_first, c * sizeof(int));
    if (temp != NULL)
    {
        iinum_first = temp; // moving temporary data to main array
    }
    else
    {
        free(iinum_first);
        printf("Error allocating memory!\n");
        return 1;
    }


    temp2 = (int*)realloc(iinum_second, c2 * sizeof(int));
    if (temp2 != NULL)
    {
        iinum_second = temp2; // moving temporary data to main array
    }
    else
    {
        free(iinum_second);
        printf("Error allocating memory!\n");
        return 1;
    }

    for (i = 0; num_first[i] != '\0'; i++)
    {
        switch (num_first[i])
        {
        case 48:
            iinum_first[i] = 0;
            break;
        case 49:
            iinum_first[i] = 1;
            break;
        case 50:
            iinum_first[i] = 2;
            break;
        case 51:
            iinum_first[i] = 3;
            break;
        case 52:
            iinum_first[i] = 4;
            break;
        case 53:
            iinum_first[i] = 5;
            break;
        case 54:
            iinum_first[i] = 6;
            break;
        case 55:
            iinum_first[i] = 7;
            break;
        case 56:
            iinum_first[i] = 8;
            break;
        case 57:
            iinum_first[i] = 9;
            break;
        }
    }

    for (i = 0; num_second[i] != '\0'; i++)
    {
        switch (num_second[i])
        {
        case 48:
            iinum_second[i] = 0;
            break;
        case 49:
            iinum_second[i] = 1;
            break;
        case 50:
            iinum_second[i] = 2;
            break;
        case 51:
            iinum_second[i] = 3;
            break;
        case 52:
            iinum_second[i] = 4;
            break;
        case 53:
            iinum_second[i] = 5;
            break;
        case 54:
            iinum_second[i] = 6;
            break;
        case 55:
            iinum_second[i] = 7;
            break;
        case 56:
            iinum_second[i] = 8;
            break;
        case 57:
            iinum_second[i] = 9;
            break;
        }
    }

    return 0;
}

Answer 1

I fixed it. 我修好了它。 i had to use realloc in main before i call convert function. 在调用转换函数之前，我必须在main中使用realloc。

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#define SIZE_MAX 10
#define SIZE_USE (SIZE_MAX-1)

int input(char num_first[], char num_second[]);
int convert(int iinum_first[], int iinum_second[], char num_first[], char num_second[], int firstlen, int secondlen, int c, int c2);

int main()
{

    char num_first[SIZE_MAX]; // original input as string
    char num_second[SIZE_MAX];

    input(num_first, num_second);

    int firstlen = strlen(num_first)-1;
    int secondlen = strlen(num_second);

    int i, c=0, c2=0;
    for (i = 0; i <= firstlen; i++)
    {
        c++; // counts number of elements needed to resize array
    }
    for (i = 0; i <= secondlen; i++)
    {
        c2++;
    }

    int *iinum_first = NULL; // converted integer input
    int *iinum_second = NULL;

    iinum_first = (int*)malloc(sizeof(int));
    iinum_second = (int*)malloc(sizeof(int));

    int *temp = NULL;
    int *temp2 = NULL;

    temp = (int*)realloc(iinum_first, c * sizeof(int));
    if (temp != NULL)
    {
        iinum_first = temp; // moving temporary data to main array
    }
    else
    {
        free(iinum_first);
        printf("Error allocating memory!\n");
        return 1;
    }


    temp2 = (int*)realloc(iinum_second, c2 * sizeof(int));
    if (temp2 != NULL)
    {
        iinum_second = temp2; // moving temporary data to main array
    }
    else
    {
        free(iinum_second);
        printf("Error allocating memory!\n");
        return 1;
    }

    convert(iinum_first, iinum_second, num_first, num_second, firstlen, secondlen, c, c2);

    printf("first integer: ");
    for (i = 0; i < firstlen; i++) // print first integer
    {
        printf("%d", iinum_first[i]);
    }
    printf("\nsecond integer: ");
    for (i = 0; i < secondlen; i++) // print second integer
    {
        printf("%d", iinum_second[i]);
    }
    puts("");

    return 0;
}

int input(char num_first[], char num_second[])
{
    FILE *fPTR;
    int i;

    if ((fPTR = fopen("input.txt", "r")) == NULL)
    {
        puts(":( File could not be opened.");
    }
    else
    {
        if (fgets(num_first, SIZE_MAX, fPTR) != NULL)
            printf("first string: "); // print string input
        puts(num_first);
        if (fgets(num_second, SIZE_MAX, fPTR) != NULL)
            printf("second string: ");
        puts(num_second);
        fclose(fPTR);
    }

    return 0;
}

int convert(int iinum_first[], int iinum_second[], char num_first[], char num_second[], int firstlen, int secondlen, int c, int c2)
{
    // dynamic memory allocation
    int i;

    for (i = 0; num_first[i] != '\0'; i++)
    {
        switch (num_first[i])
        {
        case 48:
            iinum_first[i] = 0;
            break;
        case 49:
            iinum_first[i] = 1;
            break;
        case 50:
            iinum_first[i] = 2;
            break;
        case 51:
            iinum_first[i] = 3;
            break;
        case 52:
            iinum_first[i] = 4;
            break;
        case 53:
            iinum_first[i] = 5;
            break;
        case 54:
            iinum_first[i] = 6;
            break;
        case 55:
            iinum_first[i] = 7;
            break;
        case 56:
            iinum_first[i] = 8;
            break;
        case 57:
            iinum_first[i] = 9;
            break;
        }
    }

    for (i = 0; num_second[i] != '\0'; i++)
    {
        switch (num_second[i])
        {
        case 48:
            iinum_second[i] = 0;
            break;
        case 49:
            iinum_second[i] = 1;
            break;
        case 50:
            iinum_second[i] = 2;
            break;
        case 51:
            iinum_second[i] = 3;
            break;
        case 52:
            iinum_second[i] = 4;
            break;
        case 53:
            iinum_second[i] = 5;
            break;
        case 54:
            iinum_second[i] = 6;
            break;
        case 55:
            iinum_second[i] = 7;
            break;
        case 56:
            iinum_second[i] = 8;
            break;
        case 57:
            iinum_second[i] = 9;
            break;
        }
    }

    return 0;
}

Answer 2

You can simplify the program using atoi instead of creating a new weel, but I see the only difference in 您可以使用atoi而不是创建新的weel来简化程序，但是我看到的唯一区别是

int firstlen = strlen(num_first)-1; instead of 代替

int firstlen = strlen(num_first);

在C中从字符串转换为整数时发生内存泄漏（？）

问题描述

2 个解决方案

解决方案1
0 2015-04-07 21:20:32

解决方案2
0 2015-04-07 21:26:03

在C中从字符串转换为整数时发生内存泄漏（？）

问题描述

2 个解决方案

解决方案1 0 2015-04-07 21:20:32

解决方案2 0 2015-04-07 21:26:03

解决方案1
0 2015-04-07 21:20:32

解决方案2
0 2015-04-07 21:26:03