Unix programming

Prerequisites

Linux os

Ex:

- Ubuntu 16.04, 20.04.
- Fedora
- Debian

Experiment Environment

• Fedora/Ubuntu/Red Hat Enterprise/CentOS

  • The CSIE server: Ubuntu
  • My laptop: Ubuntu 16.04

• With GNU tool-chain

  • gcc (the C compiler)
  • gdb (the GNU debugger)

Why learning UNIX?

• Academic research
  • Lots of open-source free software
  • Innovative software appears on UNIX first
  • Network computing research (cluster/grid)
  • Embedded system and SoC (system-on-chip)
  • Most of embedded software are Linux-based

   - MOST IMPORTANT: 
   - Make me more familiar on playing computer!

Topics Covered

• UNIX architecture
• File System Operations
• Terminal I/O
• Concurrent Programming
• process/thread, signals, semaphores, IPC, etc.
• Network Computing
• Socket, RPC

Prerequisites

• Setup my Linux environment

  • Use the embedded system LAB (dual-boot w/ Fedora)
  • Use my own computer
    • Most of Linux distribution (e.g. Fedora 9+) supports dual-boot
    • I can still have my M$-Windows with Linux

• Test the following software works

  • Shells: bash, tcsh, etc
  • Programming tools: gcc, gdb, make
  • My favorite X-window: KDE/Gnome
  • My favorite GUI debugger (ddd, kdbg, etc.)
  • My favorite text editor (kwrite, emacs, vi, etc.)

First UNIX instruction I should learn

• man
  • man command to look for how to use certain command
    • Example: man gcc
• info
  • Example: info gcc for detailed manual of gcc compiler

Projects introduction

1. Write the first program:

   • Write the Makefile to build the executable program in sub-folder hw_01.

     • Three functions spread across multiple files: main, calculate, mult.
     • There is no source code for function mult, only the compiled object code in lib_mult.a.
     • The correct execution result is X=610.

   • The executable program I build should:

     • Correctly execute, and
     • Be able to run in a debugger

2. Define my own fstream class.

   • Build a standard C++ class using system calls.
   • Write a class named myfstream.
     • Similar functionality to the standard C++ class fstream.
     • Contains at least these methods:
       • Open
       • Close
       • Read
       • Write
       • Operator <<
       • Operator >>
   • Requirements to my program(Learn how C/C++ standard libraries are built):
     • Build the library and deliver to other users.
       • Separate .h file.
       • Build the library file libmyfstream.a.
     • Test my program by other users.
       • Deliver only .h and .a files.
       • C++ source code on methods implementation should not be delivered to the test users.
     • I am not allowed to use any C/C++ standard library functions/classes.
       • Only UNIX system calls are allowed.

3. Recursive into a directory tree and visit each file.

   • Program to:
     • Recursion into a directory tree and visit each file.
     • Print out file name and the number of lines in each file.
       • Assume each file is a text file.
         
         
         

4. On-line messenger.

   • Suppose I want to write such a program:
     • List all my friends on-line.
       
     • Send a message to one of my friends.
   • What do I need to know?
     • A simple messenger to send a string to other’s terminal.
       

5. Database management program with auto recovery.
   
   

   • A database management program with auto recovery.
   • Back-end Process:
     • Always alive even the front-end is closed.
     • Store data in a linked list.
   • Auto-Recovery:
     • Automatic save data to disk:
       • Ctrl+c

   

6. Matrix mulplication in parallel.

   • Goal:
     • Guide me to write parallel program computing the dot-product.
     • With shared memory mechanism of UNIX.
   • Write a dot-product with pthread.
     
   • I may modify from pthread_acc.
   • Estimate the execution time and compare to sequential execution.

Final project Introduction

• There are three projects that I could choose.

  1. Parallel sorting over 1M floating-point numbers

     • Sort 1M floating point numbers in non-descending order.
     • Execute on a 4-core PC.
     • Scored by the execution time, the smaller is better.

  2. File syncing to the cloud

     • Major Function: sync all files in a dedicated directory to a remote server.
       • Like dropbox

        - Not contributing much system workload

     • Expected Result:
       • Automatic backup files (in a flat directory) to another directory.
     • Extra Function:
       • Automatic upload to a remote server.
       • Automatic sync the whole directory tree.

  3. Login shell

     • A shell program capable of execution a single command each time.
       • Basic functionality:
         • cd, mkdir, set environment variables.
         • Automatic path search.
       • Single machine.
       • Login shell through network.
     • Bonus:
       • Redirect outcome to files.
       • Piped job execution.
       • Execute background job.
• I chose the first selection one as my final project: Matrix mulplication in parallel.