Transcript The Personal Computer and its file management

The Personal
Computer and its
file management
An introduction for non-MS users
Overview
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Introduction to File Management
Some important techniques
An example : CDS/ISIS file structure
Networking
Security issues
Introduction
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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)
Hierarchical File Structure
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All files are stored in a (inverterd) tree-like
hierarchical structure :
ROOT C:\
C:\WINDOWS
C:\WINDOWS\SYSTE
M32
C:\Program Files
C:\Documents
and Settings
C:\TEMP
C:\ISIS
C:\ISIS\PROG
C:\ISIS\DATA
C:\ISIS\MENU
C:\ISIS\DATA\CDS
C:\ISIS\DATA\MYDB
File Names
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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. MyArti~1.doc
Types of files
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‘Executable files’ : extensions
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.exe
.com
.bat
.dll (only when called by .exe)
> binary files
Data-files : all other extensions
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E.g. .doc, .txt, .dbf, .mdb, .php, .htm(l)
ISIS : .MST, .XRF, .PFT, .FST, .IFP …
> binary (or mixed) or ASCII (readable characters only)
files
File Associations
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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
(Tools|Folder Options|File Types|…) or : Rightclick|Properties|Open With|.. or …
Make file extensions visible !
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Windows ‘hides’ known extensions and
provides icons to distinguish them, but…
In order to fully control your system :
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My Computer|Tools|Folder Options|View|uncheck
‘hide extensions for known file types’
The command-line
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Open a black ‘DOS-box’ or console
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> Start|Run|’cmd’ (or ‘command’ previously)
Type commands at the command prompt (no
case-sensitivity) :
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E.g. ‘dir’
E.g. ‘cls’
E.g. dir |more
E.g. dir >filelist
E.g. type filelist
E.g. edit filelist
- CD windows
- cd system32
- cD ..
- Cd \windows\system32
- cd \
- del *.* (???!!?!!??)
Working with ASCII-files
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ASCII : only the first 256 characters defined in the
ASCII (or UNICODE-)table can be used
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First 128 : fixed, e.g. A=65 and a=97, 127=DEL, 32= ,
7=BELL etc.
Second 128 : extended, variable, e.g. 128=Ç, 156= £,
225=ß, etc.
Beware : ASCII <> ANSI (Windows table) !
NOTEPAD for editing ASCII-files, in Windows :
‘text-files’ (= with extension .TXT)
Something about (UNIX/) Linux
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More secure, rigid and professional OS
Availability :
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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 :
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Case sensitive naming
‘/’ instead of ‘\’ do denote directory-levels
Multi-user Security
ISIS-file management
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To get after full installation of WinISIS :
C:\WinISIS\
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\WinISIS\PROG\
\WinISIS\MENU\
\WinISIS\MSG\
\WinISIS\WORK\
\WinISIS\DATA\ with .PAR-files for each DB
\WinISIS\DATA\MyDB
\WinISIS\DATA\Data2 etc…
ISIS file management
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An ISIS database consists of many (at least
10) files :
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MST
XRF
IFP (N01, N02, L01, L02, CNT)
FDT
FST(‘s)
PFT(‘s)
Networking
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Protocols :
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> Network|Properties|
Windows Network Client -> LAN
TCP/IP -> Internet
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Properties : IP, Subnet, Gateway, DNS
DHCP
‘Mapping of network drives’ : added to list
of storage devices with identifier (D-Z)
Security issues
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Anti-virus
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Firewall
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What are viruses ?
Protection : all incoming data scanned for ‘signatures’
Softwares : commercial and free
Worms and Trojans
Ports protection
Windows Firewall
Pest control etc…