UNIX Frequently Asked Questions

For an introduction to UNIX, help with UNIX commands, a guide to using e-mail and the Internet, plus much more, check out our UNIX User's Guide.

Basic Account Management

1. How do I connect to the university's UNIX servers?
2. How do I create a Named Student or Faculty account on Polaris?
3. How do I create a Numbered Class account on Nova?
4. Does UMUC offer a student e-mail account?
5. I forgot my account name or password! or How do I reset an expired password?
6. How do I retrieve my MyUMUC Login? What is an EmplID?

Web site and FTP Topics

1. How do I create a Web site?
2. How do I transfer (upload or download) files between my computer and the university's servers?
3. I can't transfer files - nothing happens! 
4. How do I set permissions on a file or folder?

Programming Topics

1. How do I kill a process running under my user-id?
2. What compilers are available for use?
3. How do I compile and execute a simple JAVA program?
4. How do I compile and execute a simple C++ program?
5. How do I configure my account to run CGI Scripts?

Database Topics

1. What database do I connect to?
2. Accessing Nova-based SQL accounts through http://isqlplus.umuc.edu
3. Accessing DBCourse-based SQL accounts through http://dbcourse[1-5].umuc.edu
4. Database Lab How-to: Provides basic setup to advanced database information

Basic Account Management

How do I connect to the university's UNIX servers?

You will need to open a terminal connection to Polaris, Nova, or a dbcourse server to create a UNIX account, change a password, reset an expired password, set permissions, and perform other tasks on your account.

1. If necessary, activate your connection to the Internet. If you have a broadband connection through your ISP (FIOS, Cable, DSL, ISDN), you have an always-on connection, so there is no need to turn on the Internet each time. Dial-up users must be connected before proceeding.
2. Open a terminal window on your local computer:
   
   

   Click here for Macintosh and Linux instructions. (opens in new window)

Install UMUC's customized version of PortaPuTTY

Note: This installation must be run as an Administrator. If you do not have access to install it, try the manual configuration or Telnet methods in the next section: Miscellaneous information and Legacy connection methods.

1. Click this icon to download PortaPuTTY, preconfigured for use with UMUC resources:
   (Click Run and accept the 'unsigned program' warning)
2. The installation program begins. Click to view the license.
3. Read the legal warning and the EULA, and click to accept the legal agreement.
4. Click to begin the installation process.
5. Click to close the installation program. PortaPuTTY for UMUC will start automatically.

Run PortaPuTTY and connect to the UMUC server of your choice

To start the program, double-click the PortaPuTTY for UMUC icon on your desktop:

Find the session you want to open under Saved Sessions and double click it:

Upon connecting for the first time, you will be prompted to accept a security certificate.  Please accept it.

For login information, refer to your class instructions or the UNIX FAQ for more guidance.

The Why's and How's of using and building the UMUC PortaPuTTY solution

Miscellaneous information and legacy connection methods

Manual configuration for Windows

Please refer to the previous section before attempting manual configuration. 
The following is intended for advanced users or troubleshooting only:

1. Right-click to Download PuTTY. Save it to your desktop.

2. Double-click the file to run it.

   DBCourse server users - skip the next two steps and continue with step #5

3. In the menu on the left, under Connection click on the word SSH and change Preferred SSH protocol version from 2 to 1.

4. Click on the word Session at the top of the menu.

5. In the Host Name (or IP address) box, type polaris.umuc.edu or nova.umuc.edu or dbcourse#.umuc.edu
   (DBCourse server users - replace # with the number of the dbcourse server you connect to.)

6. Type a name for this connection such as polaris,  nova, or dbcourse# in the Saved Sessions box.

7. Click Save and then Open.

8. Upon connecting for the first time, you will be prompted to accept a security certificate. Please accept it.

   Once this setup is complete, you will only need to start the program then double-click the name of the session you want to open from the Saved Sessions box.

Alternate method of connecting - Telnet

Telnet provides a simple terminal connection to a remote server. Because of its inherent lack of security, support for telnet is being depreciated in favor of the more secure SSH protocol.  Follow the instructions in the previous section to install PortaPuTTY and create a Secure SHell (SSH) terminal connection to the university's UNIX servers.

• Telnet is accessed through Windows by clicking Start > Run, then enter the following in the Run prompt telnet polaris.umuc.edu as seen below.
  
  
  
  If connecting to nova enter telnet nova.umuc.edu
  
  To activate Telnet in Vista:

  1. Go to Start, Control Panel.

  2. Click Programs and Features.

  3. Click Turn Windows features on or off.

  4. Put a checkmark in the "Telnet Client" option.

  5. Click OK.

• WARNING: Using telnet exposes your plain text username and password to all connection points between your computer and the destination server. It is therefore recommended that all terminal connections be made over SSH instead, as the username and password are encrypted during transmission. Follow the instructions in the previous section to install PortaPuTTY and connect using SSH.

Password changes don't work - Protocol Error

If you are attempting to use the chgpass command and it is prompting for a password, or cannot create or log into your new account, the most common cause is that the protocol version is incorrect. The Polaris and Nova servers only allow password changes to occur over SSH using protocol version 1. DBCourse servers only allow password changes to occur over SSH using protocol version 2.  Please review the above instructions to be sure that your SSH program is using the correct protocol.

Does UMUC have a phone number to dial into Nova and Polaris?

UMUC does not have a telephone number for dialing into our UNIX systems. You can use SSH to connect to the servers over your Internet connection.

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How do I create a Named Student or Faculty account on Polaris?

Using newuser - UMUC's named student account creation procedure

Named computer accounts are created on UMUC's UNIX system called Polaris.  These accounts stay active as long as you are a registered UMUC student.  Their purpose is to give each student a storage area and UMUC e-mail address while enrolled in classes.

The newuser procedure allows students to create a named computer account on-line. You MUST be sure that you know your MyUMUC username and password BEFORE you attempt to use this procedure. If you are unsure of your MyUMUC userid and password, please retrieve your login information.

1. Create a terminal session to the Polaris server.

   Note to Mac or Linux users:  If you are using SSH from the command line on a non-Windows computer, you will enter:
   ssh -1 newuser@polaris.umuc.edu and skip the next step.

2. At the login prompt, type newuser:
   
   Login: newuser (All lowercase. Press Enter)

   NOTE: You should not be prompted for a password at this point. If the server responds with:
   
   Password:
   then your protocol version is probably not correct. See the note about setting your protocol.

3. Enter your status when prompted: student (1), faculty (2) or staff (3).

4. At the Please enter your MyUMUC portal username prompt, enter your MyUMUC portal username.

5. At the Please enter your MyUMUC portal password prompt, enter your MyUMUC password. (Passwords are case sensitive. The cursor will not move as you type.)

6. You will be asked to accept our security policy. To agree to the terms of the policy, type accept and press the [ENTER] key.

7. An account will be created and your username and a temporary password will be displayed on the screen. The user ID will be up to 8 characters long, usually consisting of your first initial and last name. Numbers may exist if your last name is similar to others already in the system. The password will be 8 characters long, consisting of alternating letters and numbers.

   PLEASE BE SURE TO WRITE DOWN YOUR USER ID AND TEMPORARY PASSWORD.

8. After you have recorded your account information, press the [ENTER] key to exit the session.

9. The first time you sign onto your account, you will be required to change your temporary password that was given to you in step five. The password you choose must be between six and eight characters and contain at least one non-alphabetic character. It cannot be part of any word found in a dictionary.

   1. At the Enter OLD Password: prompt, enter the temporary password you were initially assigned in step five.

   2. At the Enter NEW Password: prompt, type in a password of your choice. Passwords must be between 6 and 8 characters in length, and must contain at least one non-alphabetic character, and must not be part of a word.

   3. At the Re-enter new password: prompt, type the new password again for verification. The connection may be lost when you press the [ENTER] key, but this means it was successful.  Reconnect and log in using your new password.

Passwords are set to expire for security reasons at various intervals. If you try to access your account and find that your password is not working as expected, please go to How do I change a forgotten password? for instructions.

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How do I create a Numbered Class account on Nova?

Using newclass - UMUC's Numbered Class account creation procedure

Class computer accounts are created on UMUC's UNIX system called Nova. Class accounts only last for the current semester and are removed within a few days after the last day of class to make space for the next semester's classes. Students are responsible for making copies of any information that they wish to save prior to that date. The newclass procedure allows students who require numbered class computer accounts to create them on-line (instructors will inform students if accounts are required.) You MUST be sure that you know your MyUMUC username and password BEFORE you attempt to use this procedure. If you are unsure of your MyUMUC userid and password, please see How do I retrieve my MyUMUC Login?

Note: Faculty and TA accounts are created by the system administrator. Faculty and teaching assistants use chgpass to enable their accounts.

1. Create a terminal session to the Nova server.
   

   Note to Mac or Linux users:  If you are using SSH from the command line on a non-Windows computer, you will enter:
   ssh -1 newclass@nova.umuc.edu and skip the next step.

2. At the login prompt, type newclass:
   Login: newclass (All lowercase. Press Enter)

   NOTE: You should not be prompted for a password at this point. If the server responds with:
   Password:
   then your protocol version is probably not correct. See this note about setting your protocol.

3. At the Please enter your MyUMUC portal username prompt, enter your MyUMUC portal username.

4. At the Please enter your MyUMUC portal password prompt, enter your MyUMUC password. (Passwords are case sensitive. The cursor will not move as you type.)

5. After a brief pause while your registration information is checked, the classes for which you are currently registered will be listed, and one of the following three messages will be displayed for each class:

   Account not needed : No computer account is required for this class, or if an account is needed, it is not the type created by the newclass procedure.

   Account already exists : An account was created for you or you have previously used newclass to create an account for this class.

   Account will be created: An account will be created for this class during this newclass session.

6. After you have read the information displayed on the screen, press the [ENTER] key to generate your account(s). Accounts will be created for all classes that require them. This process may take several minutes to complete, especially if there are other users accessing newclass at the same time.

7. MAKE A NOTE OF YOUR ACCOUNT NAME AND TEMPORARY PASSWORD INFORMATION.

8. Note to dbcourse and Oracle users: Your Oracle password is this temporary password, so don't throw it away!

The account name will be in the syntax of: cm325b04 (2 letters, 3 numbers, 1 letter, 2 numbers). The password will be 8 characters long and consists of alternating letters and numbers. Copy each carefully and then press Enter to clear the screen. If more than one account is created, the system will display a screen of information for each account.

Note: If your account is to receive special privileges (cgi-bin, SQL, Oracle), access will be granted to those at the time of account creation. For databases requiring a password (SQL, Oracle for CMST498F on Nova, and Oracle on the dbcourse servers) the initial temporary password provided during account creation can be used to login to the database. After logging into the database you may type password at the SQL prompt to reset your password. Do NOT use an "at" (@) character in your Oracle password! Because UNIX and database passwords are separate, students should be aware that if one is changed, the other remains as it was. Click here for more on SQL passwords

1. After the information for your last account has been displayed, press the [ENTER] key to exit the newclass procedure.

2. The first time you sign onto your account, you will be required to change your temporary password that was given to you in step six. The password you choose must be between six and eight characters and contain at least one non-alphabetic character. It cannot be part of any word found in a dictionary.

At the Enter OLD Password: prompt, enter the temporary password you were initially assigned in step seven.

At the Enter NEW Password: prompt, type in a password of your choice. Passwords must be between 6 and 8 characters in length, and must contain at least one non-alphabetic character, and must not be part of a word.

At the Re-enter new password: prompt, type the new password again for verification. The connection may be lost when you press enter, but this means it was successful.  Reconnect and log in using your new password.

Passwords are set to expire for security reasons at various intervals. If you try to access your account and find that your password is not working as expected, please go to How do I change a forgotten password? for instructions.

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Does UMUC offer a student email account?

At this time the school offers a text-based email account, which is hosted on the Polaris server. To create your Named Account, see How do I create a Named Student or Faculty account on Polaris?  Some assistance on using this account is available on the UNIX User's Guide

The address of the email account will be your login name followed by @polaris.umuc.edu (e.g. jsmith9@polaris.umuc.edu)

After you log into your polaris account, you may use pine, a text-based interface that allows you to read your messages. If you already have messages in this account, you will need to use pine at least once to read the messages you already received.

NOTE: Because pine requires a terminal connection to read your email, many users prefer to forward their Polaris email to an account that offers a web-based interface such as Gmail, Hotmail, Yahoo, AOL, etc.  To do this, create a file called .forward with your preferred email address inside of it.

An easy method to create a file with specific text inside of it is to echo the words and redirect them to the file.  Enter the following text at the polaris prompt EXACTLY as written (but replace the fake address with your email address):

Polaris>  echo myEmailAddress@yahoo.com > .forward  (Press Enter)

To verify that you have entered it correctly, type cat .forward and hit enter. You should see the email address you entered. If not, repeat the echo statement above until you see the correct email address.

If you want to learn more about options available to read your email on polaris please see the UNIX User's Guide.

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I forgot my account name or password! or  How do I reset an expired password?

Expired passwords will prompt you to change them as soon as you log in.  Simply create a terminal connection and log in with the old password.

The chgpass procedure can be used on UMUC's UNIX systems ( Polaris, Nova, SQL [special SQL/Oracle password info], and some dbcourse servers) to change forgotten account passwords. You MUST be sure that you know your MyUMUC username and password BEFORE you attempt to use this procedure. If you are unsure of your MyUMUC userid and password, please go to: How do I retrieve my MyUMUC Login?

1. Open a terminal window:

   Windows users: Open a terminal window to the server which holds your account - Polaris, Nova or a dbcourse server.

   non-Windows users: please refer to the special instructions for using chgpass on Polaris, Nova, or a dbcourse server.

2. At the login prompt, type chgpass:

   login: chgpass (All lowercase. Press Enter)

   NOTE: You should not be prompted for a password at this point. If the server responds with:
   Password:
   then your protocol version is probably not correct. See this note about setting your protocol.

3. At the Please enter your MyUMUC portal username prompt, enter your MyUMUC portal username.

4. At the Please enter your MyUMUC portal password prompt, enter your MyUMUC password. (Passwords are case sensitive. The cursor will not move as you type.)

5. The system will then verify your username and password information, and display your account name and a new randomly generated password.

   Nova users: If you have more than one account on the system, you will be prompted to select the class account you wish to change the password for.)

   PLEASE MAKE NOTE OF YOUR TEMPORARY PASSWORD. IT WILL NOT BE EMAILED TO YOU.

6. Press the [ENTER] key to exit the chgpass procedure.
   

7. Repeat step one and SSH to the server again.
   

8. Log in using your username and new temporary password that was given to you in step five. You will be required to change the temporary password:
   

   At the Type OLD password: prompt, enter the temporary password you were assigned in step 5 above.

   At the NEW password: prompt, enter a new password of your choice. Passwords on the UNIX servers must be between six and eight characters and contain at least one non-alphabetic character. It cannot be part of any word found in a dictionary.

   At the Re-enter NEW password: prompt, retype your new password for verification. The connection may be lost when you press enter, but this means it was successful.  Reconnect and log in using your new password.

Notes for SQL users:

Passwords for SQL are synchronized with the initial temporary password for the Nova account. If you lost this password, you will need to:

1. Reset your Nova password again using the chgpass command as detailed above.

2. Once the temporary password has been provided, log out, log back in, and you will be forced to change your Nova password.

3. After successfully changing your Nova password you may log into SQL using the following command:

Nova> sqlplus

4. Use your Nova username and the temporary password issued in step #2 above to log into SQL.

5. Once you are logged into SQL, issue the following command to change the password:

   SQL> password

   Do NOT use an "at" (@) character in your Oracle password!

6. Be sure to record both your Nova username and password as well as the SQL password for future access.
   

Notes for Non-Windows users:

Using chgpass on Polaris or Nova from a non-Windows computer

If you are using SSH from the command line on a non-Windows computer, you will enter chgpass in place of the username:

ssh -1 chgpass@polaris.umuc.edu
or
ssh -1 chgpass@nova.umuc.edu

and then skip over step #2.

Using chgpass on a dbcourse server from a non-Windows computer

If you are using SSH from the command line on a non-Windows computer, AND you are attempting to change your password on a dbcourse server, you will enter:

ssh chgpass@dbcourse#.umuc.edu (where # is the server your account is located on)

and then skip over step #2.

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How do I retrieve my MyUMUC Login? What is an EmplID?

The EmplID is a seven-digit number that is unique for each student, staff, and faculty member. It replaces your Social Security Number as identification within school resources. If your number is less than 7 digits, please precede it with 0's until it is 7 digits long.

If you are a Student:

Please visit https://my.umuc.edu (opens in a new window) and click on Login Assistant/ Password Help and follow the instructions on that page.

A new password will then be e-mailed to your email account on record (please be sure to check your spam/junk mail folder, some email agents mistake the email as unwanted spam).

If you are a Staff member, please use your Network Login ID for MyUMUC access.

If you are a Faculty member, please call 1-877-868-2847.

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Web site and FTP Topics

How do I create a Web site?

To create your webpages, it is recommended that you use Web Authoring Software (Wikipedia links will open in a new window, and are subject to change) such as Dreamweaver, MS Frontpage, Netscape Composer, Nvu (KompoZer), or SeaMonkey - several of which are free and very powerful.  Be sure the editor you choose offers FTP Upload.

1. Configure the Web Authoring Software

   Regardless of which software you choose, it must be configured to publish to your Web site.   Each program is different, but common locations for the Publishing Site Settings are in the Edit menu or the Site menu.  These are the settings that you will need to provide (use your username in place of jsmith9):

Site Name:

My Polaris Web site

HTTP (or IP) address of Web site:

http://polaris.umuc.edu/~jsmith9

Publishing server (or FTP address):

ftp://polaris.umuc.edu/~jsmith9/www

Username and password:

(enter your UNIX account username and password)

2. Configure your UNIX account
   
   Before you can publish your webpages to the Polaris server, you must first log into Polaris and configure your web folders.  You will be creating a subfolder called www in your account on Polaris (or Nova). Only files within this www folder will be visible to Web browsers. Therefore, all of your .html and graphic files (.jpg, .gif, .jpg, etc.) will go into this folder.   To prepare your UNIX account to host your webpage, follow these steps:

   1. Log into your account through a terminal connection.
      

   2. Grant world search access on your home directory. This is needed to allow web users to read your web files. Make sure that you type the periods (.) as shown in the examples.  Press enter at the end of each command:

   Polaris> cd (Unix does not respond to every command - the silence means it worked!)
   Polaris> chmod 711 .   (Don't forget the period!)

   3. Create a directory named www under your home directory. This is where all files for your web page will go. You will need to grant world search access to this directory as well:

   Polaris>  mkdir  www
   Polaris>  chmod  711  www
   Polaris>  exit
   

   4. Your Polaris or Nova account is now set up to host your web page(s).

3. Design and publish the page

   While designing your page, remember to save often. If you save your webpage as a file called index.html, it can serve as your default home page. When you are ready to publish the webpage to the Internet, find the Publish or Put function of your web authoring software to move the webpages to the Polaris server. Be sure to check the box for Include images and other files. If publishing results in an error, double check your site settings (the first step in this section). If you have unknown errors, you may have exceeded your quota.

   Manual Instructions (without Web Authoring Software)

   As an alternative to creating your text files on your PC and transferring them to Polaris or Nova, you may be asked to use a text editor on Polaris or Nova to create your .html files. You would still need to transfer image files to your www directory from your PC. Using one of the editors on Polaris or Nova (such as vi, jed, pico or emacs), create a document in your www directory named index.html. Here is a very basic html file:

<html>
	<body>
		The content of the webpage goes here.
		Thanks for visiting my site!
	</body>
</html>

Save the file to your www folder as index.html.  Now set the permissions - all of the files in the www directory must have world read privileges so they can be read by anyone and displayed in a browser:

Polaris> cd www
Polaris> chmod 644 *.*

Don't forget to use chmod 644 *.* as shown above any time you create a new document in the www directory that is part of your Web page!

4. Accessing the Webpage from the Internet

   You can access your Web page by using the URL: http://polaris.umuc.edu/~userid (where userid is your userid). For example, if Jane Smith had an account named jsmith9 on Polaris and she just finished setting the permissions on her Web page, she would advertise her URL as: http://polaris.umuc.edu/
   ~jsmith9
   
   A link would be coded like this:
   

   <A HREF="http://polaris.umuc.edu/
   ~jsmith9">Here's my site!</A>

   The above link would appear in a browser as: Here's my site!
   (Clicking the link above results in a Not Found error because jsmith9 is a fictitious account.)
   

   Because you are storing files on a Unix-based server, the spelling of all your files names is case sensitive. This means that capital and lower-case letters are different.  For example,  index.html is a different file from Index.html!  In addition, please avoid using filenames that contain spaces. 

If you elected not to name your first page index.html, you will need to specify a filename after your userid and a slash (/) like this:
http://polaris.umuc.edu/~jsmith9/
filename.html

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How do I transfer (upload or download) files between my computer and the university's servers?

FTP (File Transfer Protocol) is a method of moving files from one computer to another over the Internet. It can be used to upload files from your PC to remote systems such as Polaris and Nova, and also to download files from remote systems to your PC. FTP is not recommended to move Web site files because of unnecessary complications introduced regarding file permissions and relative links. Use Web Authoring Software instead.

You may use FTP at the command line, through a browser (try typing this in your address bar: ftp://username@polaris.umuc.edu), or with the assistance of a full client. We recommend using a full client such as CoreFTP. CoreFTP LE is available for use free of charge for unlimited personal and educational use. See their Web site for details: http://www.coreftp.com/

Download and Installation instructions

1. Point your Web browser to the CoreFTP download site: http://www.coreftp.com/download.html

2. Select a mirror by clicking on any of the links under the heading: CoreFTP LE: Free Version

3. If prompted, click Run and click OK.

4. Read the instructions and accept all defaults by clicking Next then click Finish.

Running the Program and Entering Site Information

1. When first starting CoreFTP, you are prompted to make CoreFTP your default FTP client. Select Cancel to leave your browser settings unchanged (recommended).

2. You are prompted to use notepad.exe to edit ASCII files. Click Yes unless you are using an older version of Windows (95, 98 or ME).

3. The Site Manager pops up. If not, click on Sites > Site Manager to open it. Change the words New_Site to a more descriptive name for this account (i.e.: Polaris or Nova).

4. Enter the site information as follows:
   
   

   Site Name:	Polaris or Nova
   Host / IP / URL:	polaris.umuc.edu or nova.umuc.edu
   Username:	Your account name
   Password:	Your account password
   Leave all other settings as default except SSH/SFTP as explained below.

    

5. To increase both your security and the ability to pass through a firewall, please put a check mark in the box for SSH/SFTP .

6. Click Connect.

7. Answer Yes to accept the security certificate.

8. To disconnect, either close the program or press the Disconnect icon on the far right of the remote site (two red dots)
   
   To reconnect or to add another site: Open the program and click New Site to add another site, or Connect to reconnect to the last site again.

Transferring Files

The general appearance of an FTP program shows your local (C:) drive on the left side, and the remote site (Polaris or Nova) on the right side. Your goal is to move files from one side to the other.

To transfer a file or selection of files (hold down Ctrl to select multiple files), select the file(s) and drag them to the other window (or click one of the two arrows in the center of the screen named Upload or Download which points in the direction of desired file transfer.)

NOTE: After a period of inactivity, the connection will time out and you will need to re-establish a connection to the system by clicking on the Reconnect button on the far right of the remote site (two blue dots).

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I can't transfer files - nothing happens!

This is usually caused by having too many files on your account. To display your disk quota information, SSH to Polaris or Nova and type quota  -v at the system prompt. You will see something like this:

Polaris> quota -v
Disk quotas for username (uid 12345):
Filesystem	usage	quota	limit	timeleft	files	quota	limit	timeleft
/users/student
	3367	4000	5000		32	0	0

In the above example, the user is using 3367 kilobytes (approximately 3.3 megabytes) out of 4000 kilobytes (4 megabytes) permitted. If the user uses more than the value specified in the quota field, she will begin to receive warning messages, however she can temporarily exceed her quota up to the value listed in the hard limit field (5 megabytes in this example).

For additional information on the use of the quota command, type man quota at the polaris or nova prompt.

SQL users may check their quota after logging into Oracle by typing the following:

SQL> select bytes,max_bytes from dba_ts_quotas where username=user;

The first reported value is the number of bytes used, and the second is the quota allowed.

Temporary Storage

If you get a disk space quota error message, you can save the file in the  /tmp directory, which is a directory that is available to all users for temporarily storing files that will not fit in their accounts. Files in the /tmp directory are automatically removed after three days or when the system is rebooted (whichever comes first, although reboots are very rare).

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How do I set permissions on a file or folder?

There are several methods to set permissions on your file and directories. As an overview, your home directory is a subset of a broader set including all user and student directories.

If you are building a Web site, your www/ directory is one level below your home directory, and all web content goes into that folder:

<-- all web content must go here

To allow others to view your Web site, you must grant executable access to all folders in the path to your Web site. The administrators of Polaris and Nova have already granted executable rights to everyone for the top three folders (/, users/, and student/.) Now you need to do the same to your jsmith9/, www/, and all files and folders inside of the www/ directory.

Also, the files that are supposed to be displayed in a web browser must be world readable to allow a browser to display them.

Three different methods of Setting Permissions:

1. Using CoreFTP:

   Changing permissions using CoreFTP is accomplished by right-clicking on the file or folder and selecting Properties. Either enter the number that represents the permission for the file (711 for folders and 644 for files) or use the check boxes to set the permissions you need.

   Since your user folder is a subset of a much larger number of folders (all student accounts), it can take a long time to display and find your directory if you choose to travel up one level (by clicking on the <..> ) Another solution is to create a custom command to send to the server by clicking on Manage and then Custom Commands. Enter the following in both fields for both Cmd Name and Command:

   chmod 711 .   (don't forget the dot!)

   then click Add and then Close. Execute the command by right-clicking anywhere inside of the remote site to set the permissions of your current directory (your home directory and your www directory.)

2. Using the Command Line (also known as the Terminal):

Polaris> chmod 711 . changes the permissions of the current working directory (.) to allow a browser to navigate through it.

Polaris> chmod 711 www changes the permissions of the www/ directory to allow a browser to navigate through it.

Polaris> chmod -Rf 644 www/*.* changes the permissions of the files within the ~/www/ directory to allow them to be read by all.

3. Using a Web Browser through FTP:

   Open a web browser and type the following into the address field:

   ftp://jsmith9@polaris.umuc.edu

After you establish an FTP connection and log in, simply right-click a file or folder and choose Properties to view and change the permissions.

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Programming Topics

How do I kill a process running under my user-id?

To kill processes running under your account, first identify what processes are running using ps -fu username:

Nova> ps -fu cm141f02

UID	PID	PPID	C	STIME	TTY	TIME	CMD
cm141f02	13636	13395	0	11:08:54	pts/22	0:00	-tcsh
cm141f02	13295	13116	0	10:42:53	pts/22	0:00	javac

Using the returned information, identify which processes you want to kill. The CMD and STIME columns will be most helpful in identifying the command that started the process and the time when the process started. When you have found the process(es) you want to end, find the PID for that process and use the kill command to stop it:

Nova> kill -9 PID where PID is the Process Identification number (PID) listed in the first column of the results of the above command.

For example:

Nova> ps -fu jsmith9

UID	PID	PPID	C	STIME	TTY	TIME	CMD
jsmith9	25443	17183	5	15:47:06	pts/7	0:00	-csh
jsmith9	17034	28708	0	13:12:04	pts/4	0:04	elm
jsmith9	17045	28690	0	13:12:44	pts/4	0:01	elm

Here is the command to terminate the second and third processes in the output above:

Nova> kill -9 17034 17045

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What compilers are available for use?

Language	Compiler Name	Example of Basic Use
Java	javac Compiler	javac prog1.java
C	SunC Compiler (cc)	cc -o executable sourcefile.c
C	GNUC Compiler (gcc)	gcc -o executable sourcefile.c
C++	SunC++ Compiler (CC)	CC -o executable sourcefile.cc
C++	GNUC Compiler (g++)	g++ -o executable sourcefile.cc
Fortran	Sun Fortran Compiler (f77)	f77 -o executable sourcefile.f

For additional information on compiler use, please read the compiler's man page. For example, to read the man page for the Sun C++ compiler (CC), type man CC at the Nova> prompt.

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How do I compile and execute a simple JAVA program?

The following procedure describes how to compile and execute a simple JAVA program:

Use the pico editor to create your source code file. Make sure you give the file name an extension of .java. For example:

Nova> pico HelloWorldApp.java

NOTE: The pico editor displays a list of available commands at the bottom of the screen. Each command in the list is prefaced with a carrot (^), which indicates that you should hold down the [CTRL] key and press the key specified. For example to execute the Get Help command, hold down the [CTRL] key and press g.

Here is a simple code for demonstration purposes:

class HelloWorldApp {
	public static void main(String[] args) {
		System.out.println("Hello World!");
	}
}

Be sure to save the file with the same name as your class - in this example, you must save it as: HelloWorldApp.java

After you have created your source code file, compile it with javac. For example:

Nova> javac HelloWorldApp.java

If you received no errors in step 2, run the executable file. For example:

Nova> java HelloWorldApp  (be sure to leave off the extension)

If you received error messages in step 2, edit your source file again to correct any syntax errors, and compile (javac) the program again.
Questions about java syntax should be directed to your instructor or teaching assistant.

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How do I compile and execute a simple C++ program?

There are two c++ compilers on UMUC's UNIX systems. The standard Sun c++ compiler is named CC (note the capitalization), and the GNU c++ compiler is named g++. You can use either compiler to compile your programs.

The following procedure describes how to compile and execute a simple c++ program:

Use the pico editor to create your source code file. Make sure you give the file name an extension of .cpp, or .cc. Both compilers will interpret files with these extensions as c++ source files. For example:

Nova> pico prog1.cpp

NOTE: The pico editor displays a list of available commands at the bottom of the screen. Each command in the list is prefaced with a carrot (^), which indicates that you should hold down the [CTRL] key and press the key specified. For example to execute the Get Help command, hold down the [CTRL] key and press g.

Here is a simple code for demonstration purposes:

#include <iostream.h>
int main() {
	cout << "Hello, World\n";
	return -1;
}

Save the file with the extension of  .cpp, or .cc as indicated above.

After you have created your source code file, compile it with one of the c++ compilers. For example:

Nova> CC -o prog1 prog1.cpp
OR
Nova> g++ -o prog1 prog1.cpp

The  -o prog1 portion of the command tells the compiler to create an executable file (which is the file you actually run to execute your program) called prog1. If you omit -o prog1, by default, the compiler will create an executable file called a.out.

If you received no errors in step 2, run the executable file. For example:

Nova> prog1

If you received error messages in step 2, re-edit your source file to correct any syntax errors, and compile the program again.
Questions about c++ syntax should be directed to your instructor or teaching assistant.

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How do I configure my account to run CGI Scripts?

NOTE: THIS PROCEDURE WILL ONLY WORK FOR SPECIFIC CLASS ACCOUNTS
THAT HAVE BEEN GRANTED PERMISSION TO EXECUTE CGI SCRIPTS.
SEE YOUR PROFESSOR IF YOU NEED PERMISSION TO RUN CGI-SCRIPTS.

Nova> cd (Moves you to your home directory)

Nova> chmod 711 . (don't forget the dot!) - (Grants group and world search access)

Nova> mkdir www (Create a www directory)

Nova> chmod 711 www (Grants group and world search access)

Nova> cd www (Change to your www directory)

Nova> mkdir cgi-bin (Create a cgi-bin directory)

Nova> chmod 700 cgi-bin (Make sure group and world have no access to the cgi-bin directory)

Place your CGI scripts in the cgi-bin directory. The permissions on the scripts MUST be 700. For example:

Nova> chmod 700 myscript.cgi

Use a URL in the following format to reference a CGI-SCRIPT: http://nova.umuc.edu/cgi-bin/cgiwrap/<username>/<script_name>
For example, if Godzilla had a CGI script called smash.cgi, he would reference it with the following URL: http://nova.umuc.edu/cgi-bin/cgiwrap/godzilla/smash.cgi

The cgiwrap above may be replaced with cgiwrapd to be run with full debugging output. Also, you may use nph-cgiwrap and nph-cgiwrapd for normal and debugging use of CGI's that output binary data (e.g. GIFs).

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Database Topics

1. What Database Server do I connect to?

   Click here (opens in a new window) for a map of which database server to connect to for your class.

2. Accessing Nova-based SQL accounts through http://isqlplus.umuc.edu

   Users of databases hosted on the Nova server can access their database account through a web browser by entering the following in the address field of your browser:
   http://isqlplus.umuc.edu (opens in a new window)

3. Accessing DBCourse-based SQL accounts through http://dbcourse[1-5].umuc.edu

   Users of databases hosted on the Nova server can access their database account through a web browser by entering the following in the address field of your browser:
   http://dbcourse#.umuc.edu (this is not a live link) where # is the number of the server that hosts your account.

   Username:	Your dbcourse account name
   Password:	Your dbcourse account password
   Connect Identifier:	The first 6 characters of your account name

4. Database Lab How-to

   The Database Lab How-to (opens in a new window) provides more basic setup and advanced database information.

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