如何将输入文件中的单词放入数组？

So I'm trying to separate the words from an input file and put them into an array. However, when I try to fit them into my array during a loop, I later try to print my array and it only returns NULL for each item. Here's what I got:

所以我试图将输入文件中的单词分开并将它们放入数组中。但是，当我在循环期间尝试将它们放入我的数组时，我稍后尝试打印我的数组，它只为每个项目返回NULL。这是我得到的：

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


int main (void)
{
    FILE *inputfile;
    int table_size = 100;
    char *table[table_size];
    inputfile = fopen("input.txt", "r");
    char str[60];
    char *token;
    int i = 0;
    if (inputfile == NULL)
    {
        printf("Could not open file!");
        return 1;
    }


     while ( fgets (str, 60, inputfile)!=NULL )
     {
        token = strtok(str, " ");

        while (token != NULL)
        {
           token = table[i];
           //strcpy(table[i], token);
           i++;
           token = strtok(NULL, " ");
         }
      }

    int x;
    for (x=0; x <= sizeof(table)/sizeof(int); x++)
        {
         printf("%s \n", table[x]);
        }
    fclose(inputfile);

return 2;

}

I know the while loop separates the file into words, but for some reason I can't manage to get those words into the array properly. I have a commented out strcpy function in there because I feel like that function could help a lot, but it isn't working properly either when I try to implement it.

我知道while循环将文件分成单词，但由于某种原因，我无法正确地将这些单词放入数组中。我在那里有一个注释掉的strcpy函数，因为我觉得这个函数可以帮助很多，但是当我尝试实现它时它也无法正常工作。

I'm not sure if the problem is with memory allocation or what. I'm a beginner and transitioning from python to C, so I'm not used to memory allocation, pointers, and the like. Thanks in advance.

我不确定问题是关于内存分配还是什么问题。我是初学者，从python转换到C，所以我不习惯内存分配，指针等。提前致谢。

1 个解决方案

#1

Right now you have a two-dimensional array with an unknown amount of elements in table. You can use strdup to dynamically allocate memory for the element.

现在你有一个二维数组，表中包含未知数量的元素。您可以使用strdup为元素动态分配内存。

while (fgets (str, 60, inputfile)!=NULL) {
  token = strtok(str, " ");

  while (token != NULL)
  {
     table[i] = strdup(token);
     i++;
     token = strtok(NULL, " ");
   }
}

Also your code for printing the elements is not correct because sizeof can't determine the amount of elements in a dynamically allocated block of memory. Instead you can iterate from 0 to i (which will be the size of table)

您的打印元素的代码也不正确，因为sizeof无法确定动态分配的内存块中的元素数量。相反，你可以从0迭代到i（这将是表的大小）

int x;
for (x=0; x < i; x++)
{
  printf("%s \n", table[x]);
  free(input[x]);
}

Because of the fact strdup allocates memory you need to free it when you're done (after your call to printf).

由于strdup分配内存这一事实，你需要在完成后释放它（在你调用printf之后）。

#1