CODEWITHSUNDEEP
carraystype-conversionfgets
HelpNeeder
HelpNeeder

Reputation: 6480

Correctly store content of file by line to array and later print the array content

I'm getting some issues with reading the content of my array. I'm not sure if I'm storing it correctly as my result for every line is '1304056712'.

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

#define INPUT "Input1.dat"

int main(int argc, char **argv) {
 int data_index, char_index;
 int file_data[1000];

  FILE *file;
  int line[5];
  file = fopen(INPUT, "r");

  if(file) {
   data_index = 0;

   while(fgets(line, sizeof line, file) != NULL) {
    //printf("%s", line); ////// the line seems to be ok here
    file_data[data_index++] = line;
   }

   fclose(file);
  }

  int j;
  for(j = 0; j < data_index; j++) {
   printf("%i\n", file_data[j]); // when i display data here, i get '1304056712'
  }

 return 0;
}

Upvotes: 0

Views: 129

Answers (3)

Andras
Andras

Reputation: 3055

fgets reads newline terminated strings. If you're reading binary data, you need fread. If you're reading text, you should declare line as an array of char big enough for the longest line in the file.

Because file_data is an array of char, file_data[data_index] is a single character. It is being assigned a pointer (the base address of int line[5] buffer). If reading binary data, file_data should be an array of integers. If reading strings, it should be an array of string, ie char pointers, like char * file_data[1000]

you also need to initialize data_index=0 outside the if (file) ... block, because the output loop needs it to be set even if the file failed to open. And when looping and storing input, the loop should test that it's not reached the size of the array being stored into.

Upvotes: 1

Kelm
Kelm

Reputation: 968

From your results I assume the file is a plain-text file.

You cannot simply read the line from file (a string, an array of characters) into an array of integers, this will not work. When using pointers (as you do by passing line to fgets()) to write data, there will be no conversion done. Instead, you should read the line into an array of chars and then convert it to integers using either sscanf(), atoi() or some other function of your choice.

Upvotes: 1

Brad S.
Brad S.

Reputation: 337

I think you need to say something like

file_data[data_index++] = atoi(line);

Upvotes: 1

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