1. Files, folders, directories, URLs, and IP addresses
Craig L. Zirbel
Math 592
Spring 2008
9/16/2018
Math 592 Spring 2008

2. File Structure
How to think of where files are stored, how they are grouped
Either think of it as a tree or a nested structure
9/16/2018
Math 592 Spring 2008

3. Macintosh / Windows
Graphical interface organizes files into nested folders.
Data
Adobe
Windows
Videos
C drive
9/16/2018
Math 592 Spring 2008

4. Paths and filenames in windows
Each file has a text string that tells where it is
C:\WINDOWS\DATA\DATAFILE.DAT
Everything before the filename is called the path
The letters at the end, after the last period, are called the extension
9/16/2018
Math 592 Spring 2008

5. Paths and filenames in windows - 2
In the original DOS (Disk Operating System), filenames and directory names could be no more than 8 letters long, and extensions only 3 letters.
Case was ignored, and all files were stored with uppercase.
This still persists, to some degree.
9/16/2018
Math 592 Spring 2008

6. UNIX versus DOS Files are grouped into directories, not folders
Directories can contain files or other directories
DOS: C:\WINDOWS\DATA\DATAFILE.DAT
UNIX: /25/zirbel/public_html/592/index.html
UNIX is case sensitive! Index.html differs from index.html
Think of it as a tree: 1 2
jsmith
591
public_html
zirbel
592 25
index.html
9/16/2018
Math 592 Spring 2008

7. Accessing your files on personal.bgsu.edu
When you have an account on personal.bgsu.edu, you have permission to put files, change files, and view files in a certain directory.
Mine is /25/zirbel
Let’s use WS_FTP to poke around a bit …
9/16/2018
Math 592 Spring 2008

8. My “root” directory
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Math 592 Spring 2008

9. My public_html directory
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Math 592 Spring 2008

10. The 592 directory
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Math 592 Spring 2008

11. The /25 directory
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Math 592 Spring 2008

12. Change directory using ~zirbel
This is how to refer to your root directory even when you don’t know the complete path to it.
9/16/2018
Math 592 Spring 2008

13. Cannot change to ~yonglin
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Math 592 Spring 2008

14. Networking and addresses
personal.bgsu.edu is the network name of a computer
Following the syntax for paths and filenames, edu.bgsu.personal might be more appropriate, because it would go from general to specific.
personal.bgsu.edu/~zirbel refers to zirbel’s public_html directory, not zirbel’s root directory.
personal.bgsu.edu/~zirbel/592/index.htm
Case is important in filenames!
9/16/2018
Math 592 Spring 2008

15. IP (Internet Protocol) addresses
Computers use numbers instead of words to identify computers on the network. Each has its own.
personal.bgsu.edu is
Bgunix.bgsu.edu is
When connected, my laptop is
Webmail.bgsu.edu is
Everything at BGSU begins with 129; here we go from general to specific.
9/16/2018
Math 592 Spring 2008

16. File transfer protocol
There are programs that allow you to transfer files back and forth between two network computers
ftp on Unix and Windows
WS_FTP and WinSCP have GUI’s
Fetch on the Macintosh
Specify the remote computer and identify your username, give your password
9/16/2018
Math 592 Spring 2008

17. Web browsers
These programs can bring certain files from a remote computer to your local computer and display them. That’s all they (used to) do!
The convention is that only files in a directory called public_html in your main directory are accessible to web browsers.
If you just specify a path, like it will assume you want the file called index.html or index.htm
9/16/2018
Math 592 Spring 2008

18. Internet Terminology URL Uniform Resource Locator
http: is a scheme name. It requests a Hypertext Transfer Protocol interaction.
//personal.bgsu.edu is the domain name
ftp: is another scheme, which requests an FTP interaction with the computer
telnet: requests an interactive terminal window, like the DOS command prompt
9/16/2018
Math 592 Spring 2008

19. Operating systems UNIX DOS/Windows Macintosh LINUX 9/16/2018
Math 592 Spring 2008

20. UNIX Developed since late 1960’s Volunteer effort, in part
Many useful utility programs, including sendmail
Stable, security against hackers
Networked for years!
Many (most?) web servers run UNIX
9/16/2018
Math 592 Spring 2008

21. DOS / Windows Developed since early 1980’s
Fairly open standard, so other companies can write software for it
Not much security until recently
Relatively new to networking
Many ways for hackers to break in, many hackers working on it
9/16/2018
Math 592 Spring 2008

22. Macintosh Developed by Apple since the early 1980’s
Closed standard; only Apple can write software for it
Reasonably good for small networks
Too small for hackers to worry about much
9/16/2018
Math 592 Spring 2008

23. LINUX A version of UNIX that can be installed on a PC Virtually free
A strong competitor for Microsoft
Now the basis for Macintosh OS X
9/16/2018
Math 592 Spring 2008