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General Information for COP 3832

• On-line resources
  • HTML Reference
  • CSS Reference
  • Apache Reference
  • PERL Reference
  • CGI.pm Reference
• General Stuff
  • Review Topics for the Midterm
  • Please stop your servers on otter.aul.fiu.edu and restart them on otter.aul.fiu.edu. You will need to change the ServerName directive in httpd.conf to the new server.
  • Syllabi: Please note that I originally had the wrong date for the final exam. Please check the syllabus for the correct date.
    • Section 01, MW 2 pm.
    • Section 02, MW 6:25 pm.
  • If you do not have a solix account, then get one: School Accounts
  • If you don't have an ISP already, then you can connect to the internet through the school: Requesting a PPP account
• Assignments will be posted here
  • Submitting Homework Online from weasel, otter or solix
  • Submitting homework on-line via the Web
  • Assignment 1
    • The link from the home page should be to run-hw1-isp.cgi in your cgi-bin directory. An eraly version of the assignment had the directory as COP3832 by mistake.
  • Assignment 2
  • Assignment 3
    • Please get a new copy of run-hw3.cgi if you copied yours before 2/15 at noon.
  • Assignment 4
    • You will need to create your own script that generates a 500 error, or copy the one from ~tdowne99/COP3832/personal. You will not be able to run it as I indicated in the homework, since you have disabled scripting in user directories.
    • You may search the Apache site from this link: http://httpd.apache.org/docs/
    • To see your error documents in Internet Explorer, you need to go to the Tools|Options menu and turn off 'Friendly HTTP Error Messages'. Also, your file must contain at least 512 bytes or IE will still show the 'Friendly' messages.
    • The assignment is due before spring break.
    • If you printed a copy of the homework before Tuesday, March 5 at 11:19 PM, then please get a new copy.
  • Assignment 5
  • Assignment 6
• UNIX information
  • If you deleted some intialization files on otter and your prompt looks like >, then issue this command from your root directory:
    ~downeyt/public/bin/init_user
  • More Information About Modes
• HTML Information
  • Creating a Web Directory on Otter
  • Creating a Web Directory on Solix
  • Problem with the <P align= ...> tag
  • HTML codes for a basic web page
  • Experiment with colors
  • See what the form elements look like
  • Information on Cascading Style Sheets
• Server Information
  • You may search the Apache site from this link: http://httpd.apache.org/docs/
  • All the Apache directives in alphabetical order: http://httpd.apache.org/docs/mod/directives.html
  • Server Information
  • Requesting a port number
  • Setting up your server on otter
    • httpd.conf
    • srm.conf
    • access.conf
  • Starting, Restarting, and Stopping your server
  • MIME types
  • I have a server running that has a lot of files.
    • http://otter.aul.fiu.edu:12345
    • The log files are accessible in http://otter.aul.fiu.edu:12345/logs
• Examples of Server options
  • Language Negotiation
  • Language Negotiation Off
  • Content Negotiation
  • Content Negotiation Off
  • AddHandler
  • AddHandler Off
  • Timeout 15
• Server Side Include (SSI) Information
  • Examples of SSI commands. Notice how long it takles this file to load compared to the next two links.
  • Same file with a .html extension instead of .shtml. Notice that none of the commands were executed.
  • Same file with a .txt extension. Notice how the server decides on what to send the browser by looking at the extension.
  • A good tutorial on all of the SSI commands
• PERL Script Information.
  • Why you are getting the error: command not found
  • See what the form elements look like
  • CGI Information. Includes information on CGILib.
  • Perl Primer. It is very basic, but it covers the things I explained in class. Check for updates: last modified on Mon, Feb 26, 06:15 PM
  • Some PERL info: split, join, and pattern matching
  • Scripts from the book by chapter. I have added a few examples that I covered as well.
  • There is a directory named scripts in my ~downeyt home directory. You have access to it, just set up a ScriptAlias in your server to /home/scsfac/downeyt/public/scripts/, or use my server to access it.
  • Scripts-source on my server. This is a page that gives a double view of my public/scripts directory. You may either view a script or execute it from this page.
  • An information page for the topics of cookies, server push, browers pull, and file uploads. This information can all fit into one category: modifying the headers that the server and browser send.
  • CGI.pm Information
  • Making forms sticky Check out this link to see how to get form elements to retain their values
  • For accessing a database, use the string "+<&fd" not "+<&=$fd" as it is in the book. Also, the statement to include file control should be use Fcntl ":flock"; not use Fcntl; as it is used in some places in the book.
• Miscellaneous scripts
  • Find your current IP address
  • Look up the IP address for a domain name
  • Trace the route to a domain
  • See what the form elements look like
  • See a list of agents that have accessed the homework upload page
• Information related to accessing school resources
  • Creating a Web directory on solix
  • Information on the pine e-mail program
  • School Accounts
  • Connecting to the school from home
  • How to FTP to solix
  • Newsgroup and Mail Information
• General Web Information
  • Search Engines
  • Internet Service Providers

School Accounts

Getting a school account

As long as you are a registered student, you can have an account to use the school's computers. This account is not needed to use the PCs in the computer labs, but it is needed to long onto the computers with names: solix, serss1, xlab1, servax, servms. The account that you get will give you access to all of these computers.

To get the account, you must connect to the solix computer. When you are prompted for a user name, type the single word (no spaces) unixshell. You will then be asked some information like name and student number. Then you will be given a user name and a password. Write them down! Then you will be logged off the computer. You won't be able to access the computers for another 24 hours, while your account is being activated.

In the future, you will use your user name and password to log onto any of the named computers.

You may get more information about UnixShell from http://www.fiu.edu/~aus/accounts/student.html

Changing Passwords

Once you have a school account, it is good for many computers here at FIU. You should change your password to something other than your student number.

Changing your password on solix

From the command prompt on serss1 and solix, issue the command

        passwd

in order to change your password. You will be asked for three things:

• Your current password
• Your new password
• Your new password, again

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FAQ: Why won't the <P align="..."> tag work?

Many people are having difficulty getting the <P align="right"> working. The problem is with the header tags that start the paragraphs: Do not include the header tags inside the paragraph. Do it this way

<h1>Heading</h1>
<P align="right">
Paragraph
</P>

This will get it working. The same applies for "left" and "center".

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Submitting Homework Online from otter or solix

I have created a script that you can call from school computers to upload files to my directory. Execute the following from your directory on weasel, otter or solix:

~downeyt/cs/public/webftp/webftp.pl

and follow the instructions. Use the -h option to learn how to customize the program.

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More Information About Modes

There are three types of permissions for a file or directory: read, write, and execute.

File

• Read: it is possible to see the contents of the file
• Write: it is possible to change the contents of the file
• Execute: the file contains machine code, or the file contains a script and the name of a program to execute the script

Directory

• Read: it is possible to see the list of names of the files that are in the directory
• Write: it is possible to change the list of names of the files that are in the directory
• Execute: it is possible to access the files that are in the directory. It is possible to change (cd) to the directory.

Each file has three different access permissions

• User: the owner of the file
• Group: the group that the user belongs to. Usually, there is no such group.
• Other: every other account that is not the user, nor the user's group

The output of the ls -al command lists all the permissions. There are ten characters

• First character - type of file: d is directory, l is link, - is file
• Next three - user permissions
• Next three - group permissions
• Next three - other permissions

Each permission is assigned a numeric value. The values are chosen so that each number from 0 - 7 indicates a unique combination of permissions.

• none: 0
• e: 1
• w: 2
• we: 3
• r: 4
• re: 5
• rw: 6
• rwe: 7

To use the chmod command, determine the permissions that are required for each category of account that can access the page: user, group, other. Calculate the number for each category. There will be one number for each. Here are some examples of chmod commands

• chmod 755 public_html
• chmod 644 index.html
• chmod 711 ~
• chmod 600 httpd.conf

To get more information on the chmod command, use the man pages.

• On solix:  man -s 1 chmod
• On otter and weasel:  man chmod
• Here are the explanations of the other modes in the ls command
  • l - file locking. Only one process can access the file at one time.
  • t - sticky bit. If directory has write access, only owner of directory can rename or remove files.
  • T - sticky bit but no access. Sticky bit is on, but directory does not have execute permission.
  • s - set-user or set-group ID. A file or directory created will have the same owner as the parent directory, it will not be owned by the ID of the process creating the file or directory.
  • S - set-user or set-group ID but no access. Set-ID bit is on, but directory does not have execute permission.

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Why you are getting the error: command not found

There are several reasons for getting this error

• You do not have execute permission on your script
  chmod 755 script.cgi
• The path to perl is incorrect. Be sure you have usr and not user
  #!/usr/local/bin/perl
• You have edited your script on Windows and saved it to the U: drive, or you have cut and pasted from a Windows machine to a telnet session on Unix. This will add an extra character, ^M (0x13), to the end of each line. Unix will then try to find the command /usr/local/bin/perl^M. There is no such command, so you will get the command not found error. Once the ^M is there, it cannot be deleted easily. Here are some options for fixing this
  • I have created a script that will erase all the ^M's from a file.
    ~/downeyt/cs/public/bin/fixm.pl  your_script.cgi
    This will create a new file named newyour_script.cgi. To see what the old file looks like, try this
    ~downeyt/cs/public/bin/view.pl script.cgi
  • Open a new file using an editor on the Unix system: pico, vi, or emacs
    • pico: use ^R to include your old file into this file.
    • emacs: use ^X I to include your old file into this file.
    • vi: someone tell me how to include a file using vi.

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