[구조체패딩현상]예전에 올렸는데..다시 부탁드리네요.. 왜 결과

지금 bmp파일의 헤더를 파싱하는 프로그램을 작성중인데요.
윈도우와 유닉스가 엔디안이 틀려서 ..그런것일지?? 라는 생각도 들고요..음.

유닉스의 결과와 window의 결과가 왜 틀릴까요??
제가 관심을 가지는 값은 width와 height 이지만서두.. 왜 그런지..원인이 파악이 안네요.

음... 같은 소스를 가지고 한것인데..왜 결과가 틀린지..모르겠네요..
컴파일 :: gcc -o getWH getWH.c
window ==>

BITMAPFIELHEADER :ret[14]
BITMAPINFOHEADER :ret[40]
Remain Data :ret[2786]
bftpye[BM]bfsize[2840] bfOffBits[1078]
biSize[40] width[42] height[40] planes[1] bitcount[8] compression[0] sizeImage[0
]  XpelsPerMeter[2834] YpleMeter[2834] clrused[0] clrImport[0]
ret[14]
ret[40]
ret[2786]
file_length[2840]
Press any key to continue

unix 결과==>

getWH
6
12
BITMAPFIELHEADER :ret[14]
BITMAPINFOHEADER :ret[40]
Remain Data :ret[2786]
bftpye[BM
         ]bfsize[403374080] bfOffBits[906231808]
biSize[671088640] width[704643072] height[671088640] planes[256] bitcount[2048] compression[0] sizeImage[0]  XpelsPerMeter[302710784] YpleMeter[302710784] clrused[0] clrImport[0]
ret[14]
ret[40]
ret[2786]
file_length[2840]

vi getWH.c
"getWH.c" 179 행, 4786 문자
#include<stdio.h>
#include<string.h>
#include<math.h>
#define myPath "./3.bmp"

//win,unix  둘다 없이 했습니다. #pragma align(1)

#ifdef Win
struct  tagBITMAPFIELHEADER{
#else
struct __attribute__((packed)) tagBITMAPFIELHEADER
#end
{
unsigned        char bfType[2];      //BM
unsigned        char bfsize[4];      //파일의 크기
unsigned        char bfReserved1[2];
unsigned        char bfReserved2[2];
unsigned        char bfOffBits[4];      //실제 이미지 비트까지의 오프셋
}BITMAPFIELHEADER;

#ifdef Win
struct  tagBITMAPFIELHEADER{
#else
struct __attribute__((packed))  tagBITMAPINFOHEADER
#end
{
unsigned        char biSize[4];
        long         biWidth;
        long         biHeight;
unsigned        char biPlanes[2];      //비트플레인 수 항상 '1'
unsigned        char biBitCount[2];    //픽셀당 비트수
unsigned        char biCompression[4]; //압축유형
unsigned        char biSizeImage[4];   //이미지 크기 (바이트단위)
        long biXPelsPerMeter;  //가로 해상도
        long biYPelsPerMeter;  //세로 해상도
unsigned        char biClrUsed[4];     //실제 사용되는 색상수
unsigned        char biClrImportant[4]; //중요한 색상 인덱스
} BITMAPINFOHEADER;
#pragma align()

int bmp_open(const char *path); //1

unsigned char src_bmp[1000000]; //10M bytes 충분한 양이다.
unsigned char des_bmp[1000000]; //10M bytes 충분한 양이다.

int main()
{

  struct __attribute__((packed)) {
        char a;
        int b;
        char c;
    } foo;
    struct {
        char a;
        int b;
        char c;
    } bar;

    printf("%d\n", sizeof(foo));
    printf("%d\n", sizeof(bar));

memset(src_bmp,0x0,sizeof(src_bmp));
memset(des_bmp,0x0,sizeof(des_bmp));

bmp_open(myPath);

return 1;
}//<==main

int bmp_open(const char *path)
{
FILE *fp;
FILE *fp_des;
int i; char c;
int file_length;
int ret;
//bih
unsigned int bfsize;
unsigned int bfOffBits;
//bif
unsigned int biSize,biCompression,biSizeImage,biClrUsed,biClrImportant;
long biWidth,biHeight,biXPelsPerMeter,biYPelsPerMeter;
unsigned short int biPlanes,biBitCount;

int t;

struct  tagBITMAPFIELHEADER   bih;
struct  tagBITMAPINFOHEADER   bif;

memset(&bih,0x0,sizeof(bih));
memset(&bif,0x0,sizeof(bif));
//======================file 정보 읽어 오는 부분
fp=fopen(path,"rb");
if(fp==NULL)
{
printf("path open fail[%s]\n",path); return -1;
}
fseek(fp,0,SEEK_END);
file_length=ftell(fp);
fseek(fp,0,SEEK_SET);

ret=fread(&bih,1,14,fp);
printf("BITMAPFIELHEADER :ret[%d]\n",ret);

ret=fread(&bif,1,40,fp);
printf("BITMAPINFOHEADER :ret[%d]\n",ret);

ret=fread(src_bmp,1,file_length-(14+40),fp);
printf("Remain Data :ret[%d]\n",ret);

//check_logic 원본.
/*
restHeaderSize = bfh.bfOffBits - sizeof(bfh) - sizeof(bih);
if(restHeaderSize != 0) Error;
다시 더 읽어라.. ^^* 에러 체크 로직을 만들어야 한다.
*/

memcpy(&bfsize,&(bih.bfsize),4);
memcpy(&bfOffBits,&(bih.bfOffBits),4);
printf("bftpye[%s]",bih.bfType);
printf("bfsize[%d] bfOffBits[%d]\n",bfsize,bfOffBits);

  memcpy(&biSize,bif.biSize,sizeof(bif.biSize));
   //memcpy((long )&biWidth,bif.biWidth,sizeof(bif.biWidth));
   // memcpy((long )&biHeight,bif.biHeight,sizeof(bif.biHeight));
        biWidth=bif.biWidth;
        biHeight=bif.biHeight;

memcpy(&biPlanes,bif.biPlanes,sizeof(bif.biPlanes));
memcpy(&biBitCount,bif.biBitCount,sizeof(bif.biBitCount));
memcpy(&biCompression,bif.biCompression,sizeof(bif.biCompression));
memcpy(&biSizeImage,bif.biSizeImage,sizeof(bif.biSizeImage));
// memcpy(&biXPelsPerMeter,bif.biXPelsPerMeter,sizeof(bif.biXPelsPerMeter));
// memcpy(&biYPelsPerMeter,bif.biYPelsPerMeter,sizeof(bif.biYPelsPerMeter));
biXPelsPerMeter=bif.biXPelsPerMeter;
biYPelsPerMeter=bif.biYPelsPerMeter;

memcpy(&biClrUsed,bif.biClrUsed,sizeof(bif.biClrUsed));
memcpy(&biClrImportant,bif.biClrImportant,sizeof(bif.biClrImportant));

 printf("biSize[%d] width[%ld] height[%ld] planes[%d] bitcount[%d] compression[%d] sizeImage[%d]  XpelsP
erMeter[%ld] YpleMeter[%ld] clrused[%d] clrImport[%d]\n",
                        biSize, biWidth,biHeight,biPlanes,biBitCount,biCompression,
                        biSizeImage,biXPelsPerMeter,biYPelsPerMeter,biClrUsed,biClrImportant);

fclose(fp);
fp=NULL;
//<========================= file 정보 읽어오는 부분

fp_des=fopen("check_bmp.bmp","wb");
ret=fwrite(&bih,1,14,fp_des);
printf("ret[%d]\n",ret);

ret=fwrite(&bif,1,40,fp_des);
printf("ret[%d]\n",ret);

for(i=0;i<file_length-(14+40);i++)
{
fprintf(fp_des,"%c",src_bmp[i]);
}
printf("ret[%d]\n",i);

fclose(fp_des);

fp_des=NULL;

fp=fopen(path,"rb");
fp_des=fopen("./test_bmp.bmp","wb");

if(fp==NULL)
{
printf("path open fail[%s]\n",path); return -1;
}
fseek(fp,0,SEEK_END);
file_length=ftell(fp);
printf("file_length[%d]\n",file_length);
fseek(fp,0,SEEK_SET);
for(i=0;i<file_length;i++)
{
c=fgetc(fp);
fprintf(fp_des,"%c",c);
}
fclose(fp);
fclose(fp_des);

return 1;
}//<==bmp_open