static int IsImage(char *name) {
int magic;
int byteSwapped(int);
sqImageFile fp;
fp = sqImageFileOpen(name,"rb");
if(!fp) return 0; /* not an image */
if(sqImageFileRead(&magic, 1, sizeof(magic), fp) != sizeof(magic)) {
sqImageFileClose(fp);
return 0;
}
if(readableFormat(magic) || readableFormat(byteSwapped(magic))) {
sqImageFileClose(fp);
return true;
}
/* no luck at beginning of file, seek to 512 and try again */
sqImageFileSeek( fp, 512);
if(sqImageFileRead(&magic, 1, sizeof(magic), fp) != sizeof(magic)) {
sqImageFileClose(fp);
return 0;
}
sqImageFileClose(fp);
return readableFormat(magic) || readableFormat(byteSwapped(magic));
}
size_t sqImageFileRead(void *ptr, size_t sz, size_t count, sqImageFile h)
{
DWORD dwReallyRead;
int position;
position = sqImageFilePosition(h);
ReadFile((HANDLE)(h-1), (LPVOID) ptr, count*sz, &dwReallyRead, NULL);
while(dwReallyRead != (DWORD)(count*sz)) {
DWORD err = GetLastError();
if(sqMessageBox(MB_ABORTRETRYIGNORE, TEXT("Squeak Warning"),"Image file read problem (%d out of %d bytes read)", dwReallyRead, count*sz)
== IDABORT) return (dwReallyRead / sz);
sqImageFileSeek(h, position);
ReadFile((HANDLE)(h-1), (LPVOID) ptr, count*sz, &dwReallyRead, NULL);
}
return (int)(dwReallyRead / sz);
}
