将txt文件的每个char存储到数组中

Question

What I want to do is to read a txt file and store in a struct with a char member, every single char of my file.

Here is my code:

typedef struct charClass {
  char simbolo;
  int freq;
} charClass;

This is the significant part of main:

 input = fopen("testo1.txt", "r");  

 fseek(input, 0, SEEK_END); //Mi posiziono alla fine del file
 int dim = ftell(input); //Ottengo il puntatore corrente (n char)
 fseek(input, 0, SEEK_SET); //Rimetto il puntatore all'inizio del file

 char tmpChar;
 charClass *car;
 car = malloc(dim*sizeof(int));

 int i = 0;

 while (!feof(input)) {
   tmpChar = getc(input);
   car[i].simbolo = tmpChar; 
   printf("\n%c", car[i].simbolo);
   car[i].freq++; 
   i++;
 }  

It crashed.

I tryed to search on Web but I didn't find an answer.

I tryed to use also fscanf, and strcpy, but I couldnt get it work.

Thanks.

Answer 1

You are not allocating enough space for your charClass structure. Try replacing the malloc with this:

car = malloc(dim * sizeof(charClass));

Also, I'm not sure what you're indexing into, using the index i. It doesn't seem that you've created an array of charClasses...?

Answer 2

From the looks of your code, you're trying to store the number of times a certain character appears in a file. For that, I suggest you to code a hash function and store it into a hash table. That will be faster and less error prone.

struct hash_blob{
   char character;
   int freq;
};
static struct hash_blob hashTable[52]; /*[A-Za-z]*//*Extend this size to include special characters*/

void setZero()
{
    int i = 0;
    for(i = 0; i < 52; i++) hashTable[i].freq = 0;
}
int compute_hash(char ch)
{
    if(ch >= 'A' && ch <= 'Z'){
       return ch-'A';
    }
    if(ch >= 'a' && ch <= 'z'){
       return ch - 'a' + 26;
    }
}

void add_hash(char ch)
{
    int loc = compute_hash(ch);
    hashTable[loc].character = ch;
    hashTable[loc].number++;
}

int main(int argc, char *argv[])
{
    int ch;
    char filename = "testo1.txt";
    FILE *f = (FILE *)fopen(filename,"r");
    if(f == NULL)return 1;
    while((ch = getc(f)) != EOF){
       add_hash(ch);
    }
    for(ch = 0; ch < 52; ch++)
    {
         printf("The number of times %c appears in the file is: %d times\n",hashTable[ch].character, hashTable[ch].number);  
    }
    return 0;
}

Answer 3

You can do this easily by initializing a char array and using fgets() function.

char buffer[50];
while(fgets(buffer,50,fp))//fp is the file pointer
  {
 /*Code for checking buffer elements and you can store them in your chosen array*/
  }