Thread: Reading file in but receive segmentation fault

I'm sorry if I violate any rule since I am new here, but I do have a question regarding some segmentation fault I receive while running the code I have been working on.
I am working on a card program and this is my input:

Code:

TS QC 8S 8D QH 2D 3H KH 9H 2H TH KS KC
9D JH 7H JD 2S QS TD 2C 4H 5H AD 4D 5D
6D 4S 9S 5S 7S JS 8H 3D 8C 3S 4C 6S 9C
AS 7C AH 6H KD JC 7D AC 5C TC QD 6C 3C
3C 6C QD TC 5C AC 7D JC KD 6H AH 7C AS
9C 6S 4C 3S 8C 3D 8H JS 7S 5S 9S 4S 6D
5D 4D AD 5H 4H 2C TD QS 2S JD 7H JH 9D
KC KS TH 2H 9H KH 3H 2D QH 8D 8S QC TS

What I am trying to do is read in 52 cards name into array, set up the game and play it, when the game is done, I read the next 52 cards and play it again.

However, I encounter segmentation fault while running the program. Here is my code

Code:

#include <stdio.h>#include <stdlib.h>
#include "header.h"


extern FILE *open_file();


//function prototype                                                                  
void readData(FILE *input_file);


//main                                                                                
main(int argc, char *argv[]){
  FILE *input_file;
  char file_name[32];


  //command to run the lab and data: lab1 data                                        
  input_file = fopen(argv[1],"r");
  readData(input_file);




  fclose(input_file);


}
//other functions here                                                                
//read in the data                                                                    
void readData(FILE *input_file){
  char card_list[104];
  FILE *current_fpt;
  current_fpt = input_file;
  //check if file error or not                                                        
  if(input_file == NULL){
    printf("Error opening input file");
  }else{
    do{
      int i;
      for(i=0;i<52;i++){
        fscanf(current_fpt,"%s",&card_list[i]);
        printf("%s\n",card_list[i]);
      }
      input_file = current_fpt;
    }while(!feof(input_file));
  }
}

I appreciate your help and please tell me where I did it wrong and if there are other ways to do this.

> FILE *current_fpt;
> current_fpt = input_file;
You're not achieving anything by reassigning the file pointer to other variables...
> input_file = current_fpt;
and then assigning it back again.

> fscanf(current_fpt,"%s",&card_list[i]);
> printf("%s\n",card_list[i]);
> You are trying to read a string into a single character space.
It's actually reading into the middle of a char array - but that's not the problem.
It's the printf which follows that is expecting a pointer, and is only getting a single char.


> while(!feof(input_file));
FAQ > Why it's bad to use feof() to control a loop - Cprogramming.com

Originally Posted by nonpuz

Code:

  }else{
    do{
      int i;
      for(i=0;i<52;i++){
        fscanf(current_fpt,"%s",&card_list[i]);
        printf("%s\n",card_list[i]);
      }

You are trying to read a string into a single character space. You probably want just "card_list" as your argument but really using fscanf() without a width specifier and such a small 104 character buffer you are definitely going to run into buffer overflows as well.

My background is Java, so I am really inexperience in dealing with this in C. In java, I can make an array and read in String. What I am trying to do here is read in the input into an array and store it there so I can set up the struct later. Is there something else I can do to resolve this?

> FILE *current_fpt;
> current_fpt = input_file;
You're not achieving anything by reassigning the file pointer to other variables...
> input_file = current_fpt;
and then assigning it back again.

> fscanf(current_fpt,"%s",&card_list[i]);
> printf("%s\n",card_list[i]);
> You are trying to read a string into a single character space.
It's actually reading into the middle of a char array - but that's not the problem.
It's the printf which follows that is expecting a pointer, and is only getting a single char

Thank you. I thought that was the way to pass the current location of the file pointer in the stream, but apparently I am wrong....