Examples&Exercises:

1. Study the command;

   $ size /usr/bin/gcc /bin/sh
   

   • Try to explain what you obtained!
2. Memory layout of a C program; a program to display process memory boundary ; http://siber.cankaya.edu.tr/OperatingSystems/cfiles/code47.c code47.c
   • Study the code in detail.
   • What are the followings?

     extern int _end;
     extern int _etext;
     extern int _edata;
     extern int __bss_start;
     extern char **environ;
     

     Make a search about them.
   • Analyze the positions and lengths of the portions.
   • Try to understand the order of the appearance of the variables (local, global, automatic, initialized, uninitialized).
   • Modify to code such that
     • able to print out the content of the variables,
     • increase the number of the arguments,
     • able to print out arguments,
     • able to print out environment.