====== C language lab ======
===== Description =====
  * To get to know the lab environment.
  * Basic process creation and shared memory handling in C language.

===== Lab Contents ======
  - Introduction to the 116 Lab
    - GNU Linux environment
      - login/logout
    - Graphical User Interface - GUI:
      - localization
      - window handling
      - file management, editing
    - Command Line Interface - CLI: 
      - shell: bash
      - localization: ''locale''
      - your friend: ''man'' [section] topic \\ (note: man displays the manual through a //pager// which allows to scroll (up/down arrows) and search (/keyword), to exit just press ''q'' as quit)
      - file management: ''ls'', ''cd'', ''cp'', ''mv'', ''mkdir''
      - process management: ''ps'', ^z, ''jobs'', ''fg'', ''bg'', &, ''echo $?''
      - command history (up/down arrows), history search: ^r 
    - Editors: gedit
  - C compiler
    - ''gcc -Wall source_file.c -o executable_file''
    - to run an executable issue: ''./executable_file''
    - Download and save the following example example: {{hello_world.c}}
    - Read the above program, is everything clear to you?
    - What does the following variables do: argc, argv, status?
    - Compile the program with gcc.
    - Run the program with different number of arguments. \\ Do you see what happens? \\ Do you know why?
    - Upon finishing check process exit (completion) status: ''echo $?''
  - Shared memory
    - Currrent Shared Memory allocation can be investigated using the following tools: ipcs, ipcrm, ipcmk
    - Download and save the following program: {{shm.c}}
    - Take a look at it. What does it do?
    - Read the manual (using 'man' command) regarding the following function calls used in the program. What do they do?
      - sleep(): ''man 3 sleep''
      - time(): ''man 2 time''
      - srand(): ''man 3 srand''
      - rand(): ''man 3 rand''
    - What does ''stop'' message represent?
    - Compile the program and run it several times.
    - Why does it give different values each time it is run?
    - Make sure, that your processes clean up Shared Memory (use ipcs, ipcrm commands).