fseek not working as expected when searching in reverse

I get garbage from the file I'm reading when I try searching in reverse. I want to go in reverse until I find the '-' character and get all characters until the next '-' but I get garbage in the resulting character string... My intention is to start searching in the middle of the file.

Code:

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

#define BLOCK 1024

void poll_file(FILE * file, char * message){

  int pos = 0, i = 0, c = 0;
  
  fseek(file, 0, SEEK_END);
  pos = ftell(file) / 2;
  fseek(file, pos, SEEK_SET);

  while((c = fgetc(file)) != '-')
    fseek(file, --pos, SEEK_SET);

  while((c = fgetc(file)) != '-')
    message[i++] = (char)c;

  message[i] = '\0';

}

int main(int argc, char ** argv){

  
  char message[BLOCK];

  FILE * file;

  if((file = fopen(argv[1], "r"))){ 
    poll_file(file, message);
    printf("Message found in image: %s\n", message);
  }
  else
    printf("Error opening file\n");

  return 0;
}

Nevermind, figured it out with a little more inspection

Code:

  while((c = fgetc(file)) != '-')
    fseek(file, -2, SEEK_CUR);

Remember on Windows OS, it makes a difference whether you opened the file in Binary or Text mode.
(Normally, but not always, binary works better.)

Tim S.