Thread: converting a binary file to a text array

Hello Everyone,

I successfully used the following code to create a text file (for use in an assembly file) from a binary file.

The problem is the code adds 2 extra bytes at the end (, 0xFFFF,). I think it has something to do with the EOF string, but I can't figure it out. I have tried for a few days now and I just can't see the problem.

Can someone help me please?

This code works and produces a text file from a binary file that looks like this:

Code:

	.db	0x49, 0x44, 0x33, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01, 0x76, 0x50, 0x52, 0x49, 0x56, 0x00, 0x00

Here is the code:

Code:

#include <stdio.h>
/*program works good except we get an extra word at the end
like this , 0xFFFF, (shouldn't be there at all)*/

FILE *fin, *fout;

int main(int argc, char **argv)
{
  unsigned short val, word_count;
//  char buffer[10];
  char buffer[20];

  printf ("argv[1]=%s\n", argv[1]);

  fin = fopen(argv[1], "rb");
  fout = fopen(argv[2], "wt");

  word_count = 0;
 
 while (!feof(fin)) {
    if (word_count == 0) {
    fwrite("\t.db\t",1,5,fout);
    }
    val = fgetc(fin);
    if (word_count < 15) {
     sprintf(buffer, "0x%02X, ", val);
      word_count++;
    }
    else {
      sprintf(buffer, "0x%02X\n", val);
      word_count = 0;
    }
    fwrite(buffer, 1, strlen(buffer), fout);
  }
  fclose(fin);
  fclose(fout);

  return (0);
}

Your problem is probably because of your use of !feof(fin) in your while loop. feof() will not fail until after you read past the end of file. See this link for a more detailed explanation.

Jim

Thanks for the link Jim, I solved the problem after some reading.