Hi, 1) Given an executable file(say a.out) is it possible from which files that executable is produced?? ie)If a.out is produced by gcc 1.o 2.o -o a.out, Given a.out file only ,can we determine a.out is produced from 1.o and 2.o?? If so how? 2) If we declare a newdatatype in a .c file , say typedef struct mytype { int a; int c; }MYTYPE; Given the executable file only, can we know any way that MYTYPE is a datatye defined in the .c file??? I tried "nm a.out". It is not printing that kind of information. Any help please. Thanks.