Hi, Perhaps a little offtopic but no harm in trying ... Can we always rely on the fact that gcc will pad the following structure? typedef struct { int descrp; SYSCALL64_STRUCT_ATTR; (Automatic padding here?) long long pos; SYSCALL64_STRUCT_ATTR; int mode; SYSCALL64_STRUCT_ATTR; } lseek64_t; What is the correct way to make it portable? Explicitly added padding fields? Thanks, Rajat - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs