LIS901N: webmastering I: the static web site

Thomas Krichel

2003-01-11

Structure of talk

• First talk about me• My concepts of webmastering• Then talk about you• Introduction to wotan• basic manipulation of wotan

– files– permissions– basic command– editing– creating your first page

About me • Born 1965, in Völklingen (Germany)• Studied economics and social sciences at the

Universities of Toulouse, Paris, Exeter and Leiceister.

• PhD in theoretical macroeconomics• Lecturer in Economics at the University of

Surrey 1993 and 2001• Since 2001 assistant professor at the Palmer

School

Why?

• During research assistantship period, (1990 to 1993) I was constantly frustrated with difficult access to scientific literature.

• At the same time, I discovered easy access to freely downloadable software over the Internet.

• I decided to work towards downloadable scientific documents. This lead to my library career (eventually).

Steps taken I

• 1993 founded the NetEc project at http://netec.mcc.ac.uk, later available at http://netec.ier.hit-u.ac.jp as well as at http://netec.wustl.edu.

• These are networking projects targeted to the economics community. The bulk is– Information about working papers– Downloadable working papers– Journal articles were added later

Steps taken II

• Set up RePEc, a digital library for economics research. Catalogs– Research documents– Collections of research documents– Researchers themselves– Organizations that are important to the research

process

• Decentralized collection, model for the open archives initiative

Steps taken III

• Co-founder of Open Archives Initiative• Work on the Academic Metadata Format• Co-founded rclis, a RePEc clone for (Research

in Computing, Library and Information Science)

Webmaster

• There are two available definitions that come to mind– A webmaster is a person who has write access to a

set of files that are available for display on the World Wide Web.

– A webmaster is a person who has control over a software installation that can deliver web pages.

• The second is more stricter. We mostly use the first one.

Webmastering

• Webmastering combines many aspects:– Work on the organization of data to fit onto pages– Set display style of different pages– Organize the contribution of data– Maintain a technical web installation

• Some of them can be learned in a course, but others can not.

• Emphasis has to be on learnable elements.

Teaching philosophy

• Point and click on a computer software is not enough.

• Explain underlying principles.• Promote standards.• Avoid proprietary software.

Webmastering I

• Deals with the maintenance of a static web site. Such a web site remains the same whatever the user does with it.

• Topics include– html– http– information architecture– web server

Webmastering II

• Deals with building dynamic web sites. – Users fill in a form– Users submit the form– Web server return a page that is specific to the

request of the user.

• Teaches a language called PHP, that is widely used to generate such web sites.– Gets you introduced to computer programming– Gets you to train analytical thinking.

Webmastering III

• Deals with XML– XML is a syntax to encode any kind of data. – XML can be constrained to only allow certain types of

data (XML Schema)– XML can be transformed to render the data in various

ways (XSLT)

• Achieve a separation of contents and presentation of a web page.

• advanced course, has both Schema and Transformation

Free software

• I maintain the server but • if

– you have Internet access– you have an old PC

you could build the server yourself. The server as well as putty and winscp are free software.

I will not now elaborate more on the nature of free software.

Communication with the server

• For file editing and manipulation, we use putty. • For file transfer, we use winscp.• Both are available on the web. • Telnet and ftp servers are not available on

wotan. Telnet and ftp do not encrypt the communication stream and therefore they are not secure.

• The protocol is ssh, the secure shell, based public-key cryptography.

Installing putty and winscp

• Go to your favorite search engine to search for putty.

• Download and save putty. • Leave your computer if it does not allow you to

do it. • Do the same thing with winscp

Debian • Is a distribution of free software that provides an

operating system and application programs• Named after Deborah and Ian Jackson• Uses the Linux kernel, but could run with other kernels• Uses mainly GNU software, based on work to write a

free version of UNIX• Therefore also called Debian GNU/Linux• Wotan runs the “testing” version of Debian, codenamed

sarge. • Usually the software is updated once a week. Let us do

it now.

Registration Time

• As part of the course, you are being provided with web space on the server wotan.liu.edu, at the URL

http://wotan.liu.edu/~username

where username is a user name that you can chose.

• It is my intention to maintain this web space for you into the foreseeable future.

• You should also choose a password, now. • I will now register you.

Login time

• Use putty, port 22 to wotan.liu.edu• set other attributes of the session as you like,

using the menu on the left, for example– colors– font shapes and sizes– bell

• Save the session as “wotan” (in the first screen) to save all the customization.

• Do the same thing at home!

Files, directories and links

• Files are continuous chunks data on disks that are required for software applications.

• A link is a file that contain the address of another file. Microsoft call it a shortcut.

• Directories are files that contain other files. Microsoft calls them folders.

• In UNIX, the directory separator is “/”• The top directory is “/” on ist own.

Home directory

• When you first log in to wotan you are placed in your home directory /home/username

• “cd” is the command that gets you back to the home directory.

• The home directory is also abbreviated as “~“• cd ~user gets you to the home of user user.• “cd ~” does what?

~/public_html• Is your web directory. You create it with “mkdir

public_html” in your home directory.• The web server on wotan will map requests to

http://wotan.liu.edu/~user to show the file ~user/public_html/index.html

• The web server will map requests to http://wotan.liu.edu/~user/file to show the file ~user/public_html/file

• The server will do this by virtue of a configuration option.

changing directory, listing files

• cd directory changes into the directory directory• the current directory is “.”• its parent directory is “..”• ls lists files• As an exercise, move around the directory

structure and discover the files that they hold with ls.

• IMPORTANT NOTE: bash allows completion of file and directory names with the TAB character

issuing commands

• While you are login, you talk to the computer by issuing commands.

• Your commands are read by command line interpreter. • The command line interpreter is called a shell. • You are using the Bourne Again Shell, bash.• bash allows to browse the command history with the

arrow keys• bash allows to edit commands with the arrow keys• exit is the command to leave the shell.

Users and groups

• “root” is the user name of the superuser.• The superuser has all privileges.• There are other physical users, i.e. persons

using the machine• There are users that are virtual, usually created

to run a daemon. For example, the web sever in run by a user www-data.

• Arbitrary users can be put together in groups.

Permission model

• Permission of files are given– to the owner of the file– to the the group of the file– and to the rest of the world

• A group is a grouping of users. Unix allows to define any number of groups and make users a member of it.

• The rest of the world are all other users who have access to the system. That includes www-data!

Listing files

• ls lists files• ls –l make a long listing. It contains

– elementary type and permissions (see next slide)– owner– group– size– date – name

First element in ls -l

• Type indicator– d means directory– l means link– - means ordinary file

• 3 letters for permission of owner• 3 letters for permission of group• 3 letters for permission of rest of the world• r means read, w means write, x means execute• Directories need to be executable to get in

them…

Change permission: chmod

• usage: chmod permission file• file is a file• permisson is three numbers, for owner, group

and rest of the world.• Each number is sum of elementary numbers

– 4 is read– 2 is write– 1 is excute– 0 means no permission.

• Example: chmod 764 file

General structure of commands

• commandname –flag --option• Where commandname is a name of a command• flag can be a letter• Several letters set several flags at the same time• An option can also be expressed with - - and a

word, this is more user-friendly than flags.• Let us look at an example with the ls command.

example

• ls lists files• ls -l makes a long listing• ls -a lists all files, not only regular files but some

hidden files as well– all files that start with a dot are hidden

• ls -la lists all files is long listing • ls --all is the same as ls -a. --all is known as a

long listing.

Copying and removing

• cp file copyfile copies file file to file copyfile. If copyfile is a directory, it copies into the directory.

• mv file movedfile moves file file to file movedfile. If movedfile is a directory, it moves into the directory.

• rm file removes file, there is no recycling bin!!

Directories and files

• mkdir directory makes a directory• rmdir directory removes an empty directory• rm -r directory removes a directory and all its

files• more file

– Pages contents of file, no way back• less file

– Pages contents of file, “u” to go back, “q” to quit

file transfer• you can use winscp to upload and download

files to wotan. • If uploaded files in the web directory remain

invisible, that is most likely a problem with permission. Refer back to permissions.

• chmod 644 * will put it right for the files• chmod 755 . (yes with a dot) will put it right for

the current directory • * is a wildcard for all files.• rm -r * is a command to avoid.

editing

• There are a plethora of editors available. • For the neophyte, nano works best. • nano file edits the file file.• nano -w switches of line wrapping.• nano shows the commands available at the

bottom of the screen. Note that ^letter, where letter is a letter, means pressing CONTROL and the letter letter at the same time.

your first page

• cd• mkdir public_html• cd public_html (do cd pu<TAB>)• nano index.html• edit your file• find your file on the web with a web browser.• You have written your first web page!• but your page is not likely to comply with rules of

html!

Copy and paste

• Putty allows to copy and paste text between windows and UN*X.

• On the windows machine, it uses the windows approach to copy and paste

• On the UN*X machine, – you copy by highlighting with the mouse’ left button– you paste using the middle button

http://openlib.org/home/krichel

Thank you for your attention!