big endian-small endian problem

I m getting 37376 instead of 146 for width and 27393 instead of 363 for height. I guess big endian-small endian problem has occured. plz help me to solve this problem.

Code:

---


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


typedef struct {
        char type[3];
        char code[3];
        unsigned short int width;
        unsigned short int height;
        char flags;
        char bgColorI;
        char pARatio;
}__attribute__((packed)) HEADER;

int main(int argc,char **argv)
{
        FILE *fptr;
      HEADER header;

        if (argc < 2) {
                fprintf(stderr,"Usage: %s filename\n",argv[0]);
                exit(-1);
        }
        if ((fptr = fopen(argv[1],"r+b")) == NULL) {
                fprintf(stderr,"Unable to open GIF file \"%s\"\n",argv[1]);
                exit(-1);
        }
        fread(&header,sizeof(HEADER),1,fptr);
      printf("\n Width = %d , Height =%d\n", header.width,header.height);

---

Haha, well idk what to tell you, it worked for me. The only thing I changed was a part of your struct because VS for some reason won't let me pack it that way.

Code:

---

#pragma pack(push, 1)
typedef struct {
        char type[3];
        char code[3];
        unsigned short int width;
        unsigned short int height;
        char flags;
        char bgColorI;
        char pARatio;
}  HEADER;
#pragma pack(pop)

---

If you believe this is an endian problem, do you know what your system is. This code worked for me and I am little endian.

I guess mine is also little endian, I m using Intel processor, I gues it wont work for big endian
is there any function which can solve this problem??(NUXI problem)

Well you have several options.

• You can make a function to reverse the order:
  
  Code:

  ---

  unsigned short reverse_short(unsigned short num)
{
        return (num << 8) | (num >> 8);
}

  ---

• You can call one of the networking functions like ntohs() to do the same.
• You can read the file into a char buffer, and individually store each member of the struct.

The advantage of the last two options is that your code will work on any platform.