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General Web

  • To add an image to the location bar in a newer browser, add a <link> like the following. The href should be to an icon, not a gif or jpeg. The 16x16 view of the icon will be displayed.
    <link rel="shortcut icon" href="http://www.cs.fiu.edu../images/tim.ico">

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 needed to access the computers in the lab. As long as you are registered for a CS class, you should have such an account. This account will also allow you to log into ocelot and weasel. CS Account Info

As long as you are registered for classes at FIU, you have access to a web mail account. Web Mail Account Info

There is a computer that is maintained by FIU, instead of by CS. This computer is named solix. Solix Account Info 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 and weasel The account that you get will give you access to these computers.

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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Submitting Homework

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, ocelot 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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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 thels -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 ocelot:  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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Validators

If you want to validate the code in an HTML page by using an HTML validator such as the one located at http://validator.w3.org, add the following to your HTML file:

  • Add the DOCTYPE comment as the first comment in your file
    <!DOCTYPE HTML>
  • Add the following META tag to the HEAD section of your file
    <meta charset="utf-8">

Here are some example pages and links to validators for each page.

valid.html5.internal.html
This is a valid HTML page that uses an internal style sheet to replace the old style presentation tags and attributes. It is necessary to validate the style sheet in a second validation.
Validate the Page. Validate the Style Sheet.
valid.html5.external.html
This is a valid HTML page that uses an external style sheet to replace the old style presentation tags and attributes. It is necessary to validate the style sheet in a second validation.
Validate the Page. Validate the Style Sheet.
invalid.html5.html
This is an invalid HTML 5 page that has some incorrect tags and attributes.
Validate the Page.
invalid.html5.external.html
This is a valid strict page, but the style sheet has some errors.
Validate the Page. Validate the Style Sheet. View the Style Sheet.

Older DOCTYPES allow older versions of HTML, but these are deprecated.

  • Add the DOCTYPE comment as the first comment in your file if you not using the old style presentation attributes and elements
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
  • Add the DOCTYPE comment as the first comment in your file if you are using the old style presentation attributes and elements
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  • Add the following META tag to the HEAD section of your file
    <meta http-equiv="content-type" content="text/html; charset=iso-8859-1">

Here are some example pages and links to validators for each page.

valid.transitional.html
This is a valid HTML Transistional page that uses old style presentation tags and attributes like <font> and <body bgcolor="red">
Validate the Page.
valid.strict.internal.html
This is a valid HTML page that uses an internal style sheet to replace the old style presentation tags and attributes. It is necessary to validate the style sheet in a second validation.
Validate the Page. Validate the Style Sheet.
valid.strict.external.html
This is a valid HTML page that uses an external style sheet. It is necessary to validate the style sheet in a second validation.
Validate the Page. Validate the Style Sheet. View the Style Sheet.
invalid.transitional.html
This is an invalid HTML Transitional page that has some incorrect tags and attributes.
Validate the Page.
invalid.strict.html
This is a valid HTML Transitional page, but an invalid strict page.
Validate the Page.
invalid.strict.external.html
This is a valid strict page, but the style sheet has some errors.
Validate the Page. Validate the Style Sheet. View the Style Sheet.

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Path Info in Netbeans

In order for Path Info to work properly in Netbeans for a servlet, it will be necessary to add an additional servlet-mapping for the servlet. You do not need to do this when you run servlets from ocelot. It is only necessary whey you run locally on Netbeans.

Edit the web.xml file for your web app. Look for the servlet mapping for your servlet. It will look something like this 

  <servlet-mapping>
		    <servlet-name>QueryPath</servlet-name>
		    <url-pattern>tdowne99.QueryPath</url-pattern>
		    </servlet-mapping>

Copy and paste another one of these right after this one. Edit the url-pattern by adding a /* at the end. When you are finished, you should have two servlet-mapping that look something like this 

  <servlet-mapping>
		    <servlet-name>QueryPath</servlet-name>
		    <url-pattern>/tdowne99/QueryPath</url-pattern>
		    </servlet-mapping>
		    <servlet-mapping>
		    <servlet-name>QueryPath</servlet-name>
		    <url-pattern>/tdowne99/QueryPath/*</url-pattern>
		    </servlet-mapping>

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Root Context

For some unknown reason, sometimes the ROOT web app of your host on Tomcat becomes unavailable, and it is impossible to Stop or Reload it in the manager web app.

If this happens, try deploying ROOT.

  1. Locate the Deploy section of the manager web app.
  2. Type ROOT into the WAR or Directory URL: edit box
  3. Click the Deploy button

You will most likely have two links to the / web app. One will work, the other will not. Leave both of them. Your web app should now be working.

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MySQL Commands

The name of your MySQL database on ocelot is
[an error occurred while processing this directive]_username
where username is your ocelot user name.

To access your database, log onto ocelot and type the command
mysql -h ocelot.aul.fiu.edu -u [an error occurred while processing this directive]_username -p <Enter Key>
password
You will enter your password after mysql prompts you for it. The password will be your panther id.

Once you are connected, you can change your password with
SET PASSWORD = PASSWORD('passwordhere');

Once you are connected, issue the command
use [an error occurred while processing this directive]_username

After you are in your database, you can view all tables with
show tables;
Don't forget the ; at the end.

There won't be any tables until you do your homework. Once you have a table, you can view its structure with
describe name-of-table;

You can see all the records in the table with
select * from name-of-table;

Exit mysql with
exit;

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Symbolic Link

Symbloic links are used in UNIX much like a shortcut is used in Windows. A directory can create a link to a file in another directory. To the operating system, this looks like the file exists in the current directory, eventhough it actually exists in a different physical location.

To create a symbolic link:

  1. Change to the directory where the link is to be created.
  2. Issue the ln -s command with the path to the actual file that is being linked
    ln -s /path/to/real/someFile.ext

If the link was created, then you will see the name of the linked file in the current directory, but it will be labeled as a link in a directory lising,
lrwxrwxrwx someFile.ext
This means that the file is a link and that it will have the same permissions as the actual file.

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Limiting Access to a Directory in Apache

There are four directives that are needed to restrict access to a directory in Apache. The directives belong in access.conf in a Location or Directory tag for the directory.

AuthType Basic
The authentication type is the method that the browser will use to retrieve the username and password. Basic is the simple method where the usual dialog box appears.
AuthName "Security Name"
Use the authentication name to define the string that will be displayed in the dialog box to identify which username and password are required.
AuthUserFile path_to_password_file
The authentication authority file is the path to the file that contains usernames and passwords.
Require user username1 username2
Identify the users who are allowed to access the site. 
  AuthType Basic
	    AuthName "your-user-name Apache Server"
	    AuthUserFile  /aul/homes/downeyt/etc/[an error occurred while processing this directive]/registered.passwd
	    Require user downeyt your-user-name

The above command uses the password file for uploading assignments, which is the one you need to use in order to allow me to access your site.

In the future, if you want to create your own password file, use the htpasswd command, which is located in the same dierctory as httpd. For the first user, include the -c option, which will create the password file. For additional users, do not include the -c option. 

htpasswd -c path_to_password_file username1
	    htpasswd path_to_password_file username2
You are visitor number page access count to visit this page [an error occurred while processing this directive].