The Personal Computer and its file management

1
The Personal Computer and its file management

• An introduction for non-MS users

2
Overview

• Introduction to File Management
• Some important techniques
• An example CDS/ISIS file structure
• Networking
• Security issues

3
Introduction

• The computer is a container of files which can be
  processed by the CPU
• Most files are on the harddisk in a file system
• All actions on the computer are based somehow on
  file access reading files (input) and writing
  files (output)

4
Hierarchical File Structure

• All files are stored in a (inverterd) tree-like
  hierarchical structure

5
File Names

• Proper (first) name and extension part (family
  name), separated by .
• The extension indicates the type of file
• Old style 8.3 format, e.g. MyArticl.doc
• New style long names, multiple extensions, e.g.
  MyArticle.doc.backup
• When necessary reduction of long to short names
  e.g. MyArti1.doc

6
Types of files

• Executable files extensions
• .exe
• .com
• .bat
• .dll (only when called by .exe)
• gt binary files
• Data-files all other extensions
• E.g. .doc, .txt, .dbf, .mdb, .php, .htm(l)
• ISIS .MST, .XRF, .PFT, .FST, .IFP
• gt binary (or mixed) or ASCII (readable characters
  only) files

7
File Associations

• In Windows (and other operating systems as
  interfaces) data-files can be linked to
  executables to have the executable automatically
  launched with the data-file as input when
  clicked, if the executable is fully
  Windows-compatible
• Other softwares (e.g. ISIS) provide their own
  mechanisms to automatically open data-files
• How assign extension to executable
  (ToolsFolder OptionsFile Types) or
  Right-clickPropertiesOpen With.. or

8
Make file extensions visible !

• Windows hides known extensions and provides
  icons to distinguish them, but
• In order to fully control your system
• My ComputerToolsFolder OptionsViewuncheck
  hide extensions for known file types

9
The command-line

• Open a black DOS-box or console
• gt StartRuncmd (or command previously)
• Type commands at the command prompt (no
  case-sensitivity)
• E.g. dir - CD windows
• E.g. cls - cd system32
• E.g. dir more - cD ..
• E.g. dir gtfilelist - Cd \windows\system32
• E.g. type filelist - cd \
• E.g. edit filelist - del . (???!!?!!??)

10
Working with ASCII-files

• ASCII only the first 256 characters defined in
  the ASCII (or UNICODE-)table can be used
• First 128 fixed, e.g. A65 and a97, 127DEL,
  32 , 7BELL etc.
• Second 128 extended, variable, e.g. 128Ç,
  156 , 225ß, etc.
• Beware ASCII ltgt ANSI (Windows table) !
• NOTEPAD for editing ASCII-files, in Windows
  text-files ( with extension .TXT)

11
Something about (UNIX/) Linux

• More secure, rigid and professional OS
• Availability
• Commercial versions (e.g. SCO, HP, AIX..)
• Free versions, e.g. Free BSD
• Open source version, a.o. Linux, Solaris (since
  14/06/2005!)
• Originally command consoles (like DOS), shell
  or terminal
• Now graphical (Windows-like) interface(s), e.g.
  KDE, Gnome
• Main differences file system
• Case sensitive naming
• / instead of \ do denote directory-levels
• Multi-user Security

12
ISIS-file management

• To get after full installation of WinISIS
• C\WinISIS\
• \WinISIS\PROG\
• \WinISIS\MENU\
• \WinISIS\MSG\
• \WinISIS\WORK\
• \WinISIS\DATA\ with .PAR-files for each DB
• \WinISIS\DATA\MyDB
• \WinISIS\DATA\Data2 etc

13
ISIS file management

• An ISIS database consists of many (at least 10)
  files
• MST
• XRF
• IFP (N01, N02, L01, L02, CNT)
• FDT
• FST(s)
• PFT(s)

14
Networking

• Protocols
• gt NetworkProperties
• Windows Network Client -gt LAN
• TCP/IP -gt Internet
• Properties IP, Subnet, Gateway, DNS
• DHCP
• Mapping of network drives added to list of
  storage devices with identifier (D-Z)

15
Security issues

• Anti-virus
• What are viruses ?
• Protection all incoming data scanned for
  signatures
• Softwares commercial and free
• Firewall
• Worms and Trojans
• Ports protection
• Windows Firewall
• Pest control etc