3.1 Searching the course notesIndex

The previous term’s course notes are available on the Internet here: CST8207 GNU/Linux Operating Systems I. All the notes files are also on the CLS. You can learn about how to read and search these files using the command line on the CLS under the heading Copies of the CST8207 course notes near the bottom of the page Course Linux Server. The current CST8177 term notes are searchable there, too!

3.2 The CLS Source DirectoryIndex

All references to the “Source Directory” below are to the CLS directory ~idallen/cst8177/14w/assignment09/ and that name starts with a tilde character followed by a userid with no intervening slash. The leading tilde indicates to the shell that the pathname starts with the HOME directory of the account idallen (seven letters).

You do not have permission to list the names of all the files in the Source Directory, but you can access any files whose names you already know.

3.3 Review of CST8207 account managementIndex

Review your work from CST8207 GNU/Linux Operating Systems I:

• In this assignment you will need to remember how to use: passwd, useradd, userdel, groupadd, gpasswd, usermod, chown, chgrp, chmod, chsh
• Modes and Permissions
• Modes and Permissions assignment
• Users and Groups
• Users and Groups assignment

4.1 Set Up – The Base Directory on the CLSIndex

1. Do a Remote Login to the Course Linux Server (CLS) from any existing computer, using the host name appropriate for whether you are on-campus or off-campus.

2. Create the CLS directory ~/CST8177-14W/Assignments/assignment09

3. Create the check symbolic link needed to run the Checking Program, as described in the section Part II - Check and Submit below.

Run Part II - Check and Submit to verify your work so far.

4.2 CentOS: SnapshotIndex

0. Complete your CentOS Virtual Machine Installation and Verification.
   • Make sure it passes the checks for disk sizes and package counts.
   • Complete the critical system administration tasks required in Assignment #08.
1. Before you begin this assignment, create a snapshot of your CentOS Virtual Machine.
   • Enter a comment explaining where and when you took this snapshot.
   • You can restore back to this snapshot if anything goes wrong.

4.3 CentOS: Creating a sudoers groupIndex

We will create a special sudoers group. The sudo command will be configured to permit any account in this group to become the root user and run any command with full privileges.

1. Login to your CentOS Virtual Machine as the root user (the only user).

2. Create a special group for users who will be permitted to use the sudo command, as follows:

   1. In the CentOS man groupadd manual page:
      • Read (RTFM) about the Red Hat -r system group option.
      • The login.defs file mentioned there is in the /etc/ directory.
      • The variables mentioned in the man page are not actually defined in the file – looks like a bug in CentOS.
      • The gid field for a system group will be less than the value of GID_MIN found in the file. Look up the value.
   2. Create a new system group account called sudoers
      • Make sure the group is created as a system group: is the value of the gid field less than GID_MIN?
   3. Check you work: make sure the new group appears in the group file. If it is not there, get help.
      • Is the value of the gid field less than GID_MIN?

3. Enable sudo to use the new sudoers group, as follows:

   1. Make a backup of /etc/sudoers (for example, /etc/sudoers.bak)
      • Always preserve the mode and time of files you copy!
   2. Edit the sudoers file with the visudo command (which will use the Small vi editor, not vim .
      • Refer to the course notes on how to use an editor other than vi with this command: EDITOR=vim visudo
   3. Search for the line # %wheel ALL=(ALL) ALL
      • Read the line directly above it to see what this line does.
   4. Following the model of the commented-out line for the group wheel, create a new line (and a comment above it) that allows anyone in the sudoers group to run all commands. (You will yank and put two lines and edit one of the two lines you put.)
   5. Ensure there is no comment character # at the front of the line from the previous step. The line must start with % followed by the new group name (not wheel).
   6. Save the /etc/sudoers file and quit the editor.

4. Do a file difference between your backup file /etc/sudoers.bak and the new /etc/sudoers file. Make sure that the only changes you see are the ones you intended to make. If not, restore the file (or restore a previous snapshot) and make the changes again.

   • Exactly two lines should be added to /etc/sudoers
   • Make sure this finds exactly one line: grep '^%sudoers' /etc/sudoers

Run the Fetch and Checking Program to verify your work so far.

4.4 CentOS: Creating a System Administrator AccountIndex

In this section you will create your own system administration account on your CentOS VM. This personal account can be customized for you. All work is done on your CentOS Virtual Machine.

Do not add extensive customization to the root account on a system, since such customization may not suit all root users of the system and may break automated programs that need to become the root user.

Leave the root account on your CentOS Virtual Machine alone.

References to man pages below will be to CentOS man pages, not CLS man pages. Since CentOS Linux and Ubuntu Linux are different distributions, they sometimes have different documentation and programs.

Review Users and Groups:

• The CentOS useradd command creates a new account, storing information about the account in the /etc/passwd file and about the account groups in the /etc/group file. It also creates a HOME directory for the account and places standard start-up files into it.

• The passwd command sets a password for an account, storing the password in the shadow password file named /etc/shadow. An account cannot be used until a password has been set. Group passwords (rarely used) are stored in the shadow group file /etc/gshadow.

1. Take a VMware snapshot that you can return to if things go wrong.

   • Enter a snapshot comment explaining where and when you took this snapshot.

2. If necessary, login to your CentOS Virtual Machine as the root user (the only user).

3. Make sure you have configured the sudoers group in the previous section.

   • Search for the sudoers group name in the system group file.

4. Create a system administrator account as follows:

   1. In the CentOS man useradd manual page:
      • Read the SYNOPSIS and note where the LOGIN name must be used on the useradd command line.
      • Read about the --comment option and following argument used to define your full name. The (quoted) full name argument must immediately follow the option on the command line. See below.
      • Read about the Red Hat -r system account option and how using it will require you to use the -m option as well. Remember that.
      • Read about the -m option. You must use this, too.
      • You will need to use all three of these options correctly.
      • The variables mentioned in the man page under -r are not actually defined in the given file – looks like a bug in CentOS.
      • The uid field for a system account will be less than the value of UID_MIN found in the file. Look up the value.
   2. Following the SYNOPSIS syntax given in the useradd man page, add a new system account with the following settings:
      • LOGIN: Use your eight-character College/Blackboard/CLS username.
      • COMMENT: Copy and paste the exact text used for the fifth field of your own account line in /etc/passwd on the CLS:
        • The fifth field in /etc/passwd is called the GECOS field or user’s name or comment field.
        • The text you must copy and paste from the CLS and use as a comment field on CentOS is in the form: “Firstname Lastname - CST8177-14W-4NN” where Firstname and Lastname are your name and 4NN is your own three-digit lab section number.
        • Warning: Spaces are shell meta-characters.
        • Copy and paste all this information from your GECOS entry in the CLS password file to be the (quoted) argument immediately following the --comment option.
      • Make sure the account is created as a system account with no password expiry.
      • Use the option to create the HOME directory at the same time.
   3. After creating your account with useradd, verify it:
      • Search for the newly created account line in the password file:
      • Make sure it has the correct GECOS/comment/name field that should be a copy of the same field on the CLS.
      • To be a system account, the userid number for the account must be less than UID_MIN.
      • Run id abcd0001 where abcd0001 is your new account name.
        • Verify that the uid and gid are less than UID_MIN, indicating a system account.
   4. Make sure the newly created account also has a HOME directory created in the file system. Note that some default hidden files have been put into the HOME directory, copied from the directory /etc/skel/. As system admin, you can put custom files in this directory that will be given to all accounts crated using useradd.
   5. If you didn’t succeed in creating the account and HOME directory correctly, with the correct comment (GECOS) and correct uid field, you may restore your snapshot and try again, or delete the account using userdel -r and try again.

5. Adjust the permissions of the new account HOME directory, if necessary, as follows:

   1. Set the permissions (mode) of the new HOME directory for your new account such that:
      • The owner (that is, you) can do everything
      • The group can search but not read or write
      • Other users can do nothing (no permissions)

6. Set a password for your new sysadmin account, as follows:

   1. Review the section “Choose a hard-to-guess password” in man passwd.
   2. Assign your new account a strong password that you can remember.
      • Make sure you assign the password to the new account; do not change your root account password. RTFM

   Warning: If you do not type the username argument to the password command, you are changing the password of the account that you are signed in with (i.e. the root account!). Do not change your root password! Change the password of your new non-root account.

7. Enable sudo for the new account, as follows:

   1. Review the CentOS man gpasswd manual page.
   2. Use a command to add your new account to the sudoers group. (Do not edit the group file! Use the correct system command.)
   3. Check you work: make sure your account name appears beside the new group name in the group file and in the group shadow file. If not, get help.
   4. Run id abcd0001 where abcd0001 is your account name.
      • Verify that the account has the sudoers group listed.

8. Test your new account’s ability to use sudo, as follows. (You can do this on the VMware console or via an SSH login.)

   1. Log out from the root account.
   2. Log in to your new system admin account.
   3. Look at man sudo, or search the course notes, for how to “gain root privileges” when you are a sudoer.
   4. Obtain root privileges using the sudo command to start a root privilege shell:
      • Use the -i option to set a correct root PATH that includes system administration paths such as /sbin.
      • Your shell prompt should change from $ to include the # character that indicates root privileges.
   5. If the previous step was unsuccessful, check the following:
      • Did you type your own password (not root’s) when prompted by the sudo command? Use your own password with sudo.
      • Is your sysadmin (non-root) user in the sudoers group?
      • Is there a line in the /etc/sudoers file that allows anyone in the sudoers group to run all commands? (Check your work.)
   6. When sudo works, type whoami or id to confirm that you are the root user and are in the root group.
   7. Type pwd. If you are still in your sysadmin HOME directory, you didn’t use the correct sudo option to do a full login. Try again. Using the right option will have you change to root and also change to the HOME directory of root (that is not under /home).
   8. You must not proceed until you are able to obtain root shell privileges as your sysadmin (non-root) user, because you are about to disallow root logins.
   9. You may remove /etc/sudoers.bak if everything is working correctly.

Run the Fetch and Checking Program to verify your work so far.

4.5 CentOS: Prevent root loginsIndex

Many systems increase security by making it impossible to become the root user directly using a root account password, forcing people to first login with their own account name and only then use sudo to execute privileged commands.

1. Log in to your new system administration account, if necessary, and obtain root shell privileges using the sudo command, if necessary.

   • Your shell prompt should change from $ to include the # character that indicates root privileges.
   • Make sure you have the full root PATH that includes /sbin

2. Type whoami or id to confirm that you are the root user.

3. Take a VMware snapshot that you can return to if things go wrong.

   • Enter a comment explaining where and when you took this snapshot.

4. Lock the root account password using the correct option of the passwd command.

5. Confirm that the password field for the root account in the shadow file now has an exclamation mark ! at the beginning, locking it.

6. Exit your current shell to release root privileges, so that you return to your system admin account and see a regular prompt (no # character).

7. Verify that you cannot use su to become root any more using the locked root account password.

You must now always log in as your sysadmin account and use sudo to become root.

Run the Fetch and Checking Program to verify your work so far.

4.6 CentOS: Copy your files from the CLS to your CentOS VM accountIndex

Your new system admin account is missing the shell prompt, options, and aliases of your account on the CLS. Let’s bring some selected files from the CLS to your CentOS sysadmin account.

1. Log in to your new CentOS system administration account, if necessary.

   • Exit from the root shell, if you are running as root.

2. Type whoami or id to confirm that you are not running as root.

   • You should see your own userid.

3. Take a VMware snapshot that you can return to if things go wong.

   • Enter a comment explaining where and when you took this snapshot.

4. Copy your .bashrc and .bash_profile from your account on the CLS (the remote machine) to the HOME directory of your account on your CentOS VM (the local machine) with scp, as follows:

   1. Read about using the scp command in Unix/Linux SCP Command.
   2. Use the “preserves modification times” option to the scp command.
   3. Make sure you copy in the correct direction, or you will wipe out your files on the CLS!
   4. You may find it useful to create an alias in your accounts that always uses the “preserve” option when you type the scp command name.
      • You may already have a similar alias defined for the cp command.
      • Make sure you define and save the alias on both the CLS and CentOS.

5. Log out of CentOS and log back in as your sysadmin account to make your shell environment the same as it would be on the CLS. All the options and aliases should be the same on both machines now.

6. Move your CST8177-14W directory from the root HOME directory to your own account HOME directory and recursively set its owner and group to be your userid and group. Do not leave root-owned files in your account.

Advanced users can use find to find files with the wrong owner and send those pathnames into sudo running xargs with chown. See Find and Xargs.

Run the Fetch and Checking Program to verify your work so far.

4.7 CentOS: Creating a few new users “by hand”Index

You will use the standard account management tools to create a few ordinary (non-admin) accounts, just as you did last term. You will force password expiry so that the users must change their passwords when they first log in.

1. Log in to your new system administration account, if necessary, and obtain root shell privileges using the sudo command, if necessary.

   • Your shell prompt should change from $ to include the # character that indicates root privileges.
   • Make sure you have the full root PATH that includes /sbin

2. Type whoami or id to confirm that you are the root user.

3. Take a VMware snapshot that you can return to if things go wong.

   • Enter a comment explaining where and when you took this snapshot.

4. Create three new users by running the appropriate command three times:

   1. Usernames: user001, user002, user003
   2. Full Names (GECOS comment field): User One, User Two, User Three
   3. Verify that the new accounts appear in the password file and that the HOME directories all exist.
   4. Note that the new accounts have been given default hidden files from the /etc/skel/ directory.

5. Set different, good initial passwords for the three users.

6. Force these users to change their password upon first login.

   • Search the lecture slides for how to force passwd change on login.

7. Set their HOME directory permissions to be as follows:

   • the owner can do everything
   • group can search and read but not write
   • other users can do nothing (no permissions)

Run the Fetch and Checking Program to verify your work so far.

4.8 CentOS: Create many more users in bulkIndex

Few organizations create users manually. The batch newusers command (RTFM) can read a text file and create user accounts in bulk. In this section, you will be creating a text file suitable for input to the newusers command, then using newusers to quickly create almost a hundred new accounts.

1. Log in to your new CentOS system administration account, if necessary.

   • Exit from the root shell, if you are running as root.

2. Type whoami or id to confirm that you are not running as root.

3. Take a VMware snapshot that you can return to if things go wong.

   • Enter a comment explaining where and when you took this snapshot.

4. On CentOS, make your own directory ~/CST8177-14W/Assignments/assignment09, in which you will create the files and scripts resulting from the following tasks. (You already did this on the CLS; now do it here on CentOS.)

5. Copy the file userlist.csv from the Source Directory on the CLS to the above assignment09 directory in your account on your CentOS machine.

   • Did you remember to preserve the time stamp on the file?

Imagine that the userlist.csv file was given to you from the Human Resources department by someone who created it with a spreadsheet.

Examine this file, and notice that it is in Colon-Separated-Value format. It is 98 lines: a header line and a username and a real name for each of 97 new users that need an account on your system.

The file contains five fields, separated by colons (:). Read the header line to know what the five fields are. (A real spreadsheet export would be separated by commas, but we’re making it easier for you.)

We need to create a text file suitable for batch input to the newusers command. Every line in the file we give to newusers must have the correct format: it must have the userid at the start and the seven colon-separated fields described at the top of the newusers man page.

The file given to us only has five fields, and it has a poor password set for all the accounts. We need to fix this file before we can feed it to the newsers command.

Note: If you read all the words in this section before you start working, you will save yourself some file copying by using one command pipeline (no temporary files needed) instead.

5. Create a new file called userlist.newusers based on userlist.csv, but make the following changes.

   1. Copy the userlist.csv file into the new file userlist.newusers.

   2. The first line in userlist.csv is a header line, not a user to be created; the first line must be deleted. Use a command to read the file, remove the first (header) line, and write a temporary output file. The temporary output file should be only 97 lines long. (Hint: What command shows the last 97 lines of a file? [Double Hint: That same command has a syntax to “print beginning with the Kth item from the start of each file” which allows you to skip the first line without knowing how many lines are in the file.])

   3. Move the temporary output file to be the userlist.newusers file.

      • The file should now have only 97 lines in it.
      • Make sure the header line is gone.

   4. Use sed to read the new file and on every line insert the two colon characters that correspond to the location of the missing pw_uid and pw_gid fields needed by newusers, and write a temporary output file. For example, use sed to change this line:

      user066:password:User 066:/home/user066:/bin/bash

      to this line with two more colon characters in the right place:

      user066:password:::User 066:/home/user066:/bin/bash

      on all 97 lines. (This is a one-expression sed substitution.) (Hint: You can’t simply change a colon to three colons. Use some fixed context around your expression, to select the correct colon to change.)

   5. Move the temporary output file to be the userlist.newusers file.

      • Verify that every line now has seven colon-separated fields, with three colons right after the password field.
      • There should still be exactly 97 lines in the file.

   6. All the seven fields in the file are acceptable except the pw_passwd field that currently contains password, which is not a good default password for all these accounts. RTFM to see how the pw_passwd field is used by newusers.

      • Use sed to read the new file and on every line change the pw_passwd field from the dummy value password to a single, common password that all of these new users will get. You choose the new password. (This is not very secure, but it’s the best you can do without writing a more complex script.)
      • Do not choose any obvious password such as password.
      • To make this change, use an invocation of the sed command to read this file and change the word password to the password that you made up, redirecting the output of the sed command to a temporary output file.

   7. Move the temporary output file to be the userlist.newusers file.

   8. Verify that your output file is 97 lines (no header line) and the only field that has changed in each line is the new password field.

      • Every line should contain your new password in the pw_passwd field position.

6. Realize that the above three edits could be done as one three-command pipeline that reads the original userlist.csv file, and makes each of the above three changes using filters. With a pipeline, no temporary files are needed.

   • Write this three-command pipeline and when it is working, put it in a script named convert_userlist.sh. The script should read standard input and write standard output, so that you can type:

     $ <userlist.csv ./convert_userlist.sh >userlist.newusers

   The script file will contain two or three commands (which might inclue tail and sed and maybe another sed) separated by pipe characters. (If you RTFM, you can combine the two sed commands into one sed command with two expressions, or perhaps even into one single expression that does both edits at the same time.) No file names are mentioned in the script, so that the script reads standard input and writes to standard output.

7. Verify that the userlist.newusers file contains 97 lines, seven fields per line, with good passwords.

8. Use sudo to run the newusers command with this file to create all of these 97 new users.

9. Make sure all the new users and HOME directories exist:

   • Should have account entries and HOME directories for user001 through user100
   • Use pipelines to select and count the accounts in the password, group, and shadow files. Do they all exist?
   • Use pipelines to select and count the account HOME directories. Do they all exist?
   • Note that these accounts do NOT have hidden files copied from /etc/skel/ in them. Only useradd copies these files.

4.9 CentOS: Management of the bulk usersIndex

This reviews the account management commands you learned above and in your previous term. Links to previous term notes and worksheets are given above under Review of CST8207 account management. None of the items below require you to text-edit any system files using a text editor. Actions can be performed using the correct account management commands. Most account management commands will require root permissions to run.

0. Make sure you have correctly followed all the above steps, including using the newusers command to create 97 accounts. Verify that you have created all the users and HOME directories for accounts user001 through user100 before continuing.

1. Use a system admin command to create a new group called common.

   • Do NOT edit the group file! Use the correct system admin command.
   • Do NOT make this a system group. It is a normal group.
   • Verify the change by looking in the group file.

2. Use a system admin command to add users User 004 and User 005 to the common group.

   • Do NOT edit the group file! Use the correct system admin command.
   • Verify the change by looking in the group file.

3. Create a directory called /home/common owned by your sysadmin user, and group-owned by the new common group.

4. Change the permissions on /home/common so that your sysadmin user can read/write/search, members of the common group can read/write/search, and it is not accessible in any way to other users.

5. Become User 004 without using a password (using your sysadmin powers) and as that user, create a group-writeable file in the common group called /home/common/README containing the text This common directory is for members of the common group.

   • Note the permissions on the file when you create it.
   • Make sure you change only the group and group permissions of this file.
   • Do not remove any existing permissions on the file.
   • Exit from this user004 shell to revert back to your superuser-self.

6. Become User 005, and ensure that as user005 you can edit the file /home/common/README and change the text “for members” to “for all members”.

   • If you can’t edit and save this file, fix the group and group permissions.
   • Exit from this user005 shell to revert back to your superuser-self.

7. Become User 006 and ensure that as user006 you have no access to the /home/common/ directory.

   • Exit from this user006 shell to revert back to your superuser-self.

8. Use a sysadmin command to change the “real name” (GECOS/comment field) of User 005 to: CommonUser 005

   • Do NOT edit the file! Use the correct system admin command.
   • Verify the change by looking in the password file.

9. Lock the password for User 006 and User 007.

   • Do NOT edit the file! Use the correct system admin command.
   • Verify the change by looking in the shadow file.

10. Change the shell for User 008 and User 009 to /bin/sh.

    • Do NOT edit the group file! Use the correct system admin command.
    • Verify the change by looking in the password file.

11. Use the correct command to delete the accounts for User 010 and User 011 without deleting their HOME directories.

    • Verify the change by looking in the password file.
    • Make sure their HOME directories still exist in the file system. (Note what ls tells you about the file owner now!)
    • The group entries for these accounts may also continue to exist.

12. Use the correct command to delete the user010 and user011 groups, if they are still present on your machine.

    • Do not edit the group file! Use the correct system command.
    • You may see an error about removing the shadow group entry, because the newusers command did not create shadow group entries. Ignore the error – the groups don’t exist in the group shadow file.

13. Delete the accounts for User 012 and User 013 using the option that also deletes the HOME directory at the same time.

    • Verify the change by looking in the password file.
    • Make sure their HOME directories are gone from the file system.
    • The group entries for these accounts will also be deleted.

None of the items above require you to text-edit any system files using a text editor. Actions can be performed using the correct account management commands. Most account management commands will require root permissions to run. Do not text-edit the system files!

Run the Fetch and Checking Program to verify your work so far.

4.10 CentOS: Creating a tar archive backup and listingIndex

Review the common uses of the tar command in Package Management from last term.

1. As your sysadmin account, in your CentOS Assignments directory, create a compressed tar archive of your assignment09 directory named assignment09_YYYYMMDD.tgz (no spaces), where YYYYMMDD is the date you created the archive backup.

   • Do NOT try to create an archive inside the same directory that you are saving into the archive!
   • The pathnames in the tar file must not include any parent directories of the assignment09 directory you were asked to save.

2. Move the archive you just created into your assignment09 directory.

3. Generate a verbose listing of your tar archive file, showing the contents of the archive including all the owners and date/time stamps, into file tar_tvzf.txt under your assignment09 directory.

Optional: Read the mouse-over text in this tar-related comic from the XKCD webcomic.

Run the Fetch and Checking Program to verify your work so far.

4.11 When you are doneIndex

That is all the tasks you need to do.

Check your work a final time using the Fetch and Checking Program and save the output as described below. Submit your mark following the directions below.

Optional: Keeping your base CentOS Virtual Machine snapshot, remove any intermediate snapshots you no longer require, to free up disk space. - Be careful not to remove your current work!

5.1 Part I - Fetch and CheckIndex

Do all the following steps on your CentOS Virtual Machine. Read through the whole list before you start typing anything. An example of what to type is given below the descriptions that follow.

Failure to read all the words will lock your account out of the CLS.

1. Log in to CentOS. Use your sysadmin non-root account (same userid as Blackboard) if you have created it, otherwise use the root account.
2. Create a directory named CST8177-14W/Assignments/assignment09 (use the same directory hierarchy as you already have in your own account on the CLS). If you have created your own sysadmin account already, create the above directory in the HOME of your sysadmin account, otherwise create it in the HOME directory of the root account. (This assignment will have you move it from the root account to your own sysadmin account anyway.)
3. Change to the above assignment09 directory (on CentOS!).
4. As shown below, use curl to get a copy of the Fetch program from the given URL into a file named do.sh. Make sure you have a file named do.sh in your assignment09 directory. You only need to download this once per assignment.
5. Warning: If you printed this page on paper, you may not be able to scroll right to read the whole web URL that you must pass to the curl program.

[assignment09]$ url=http://teaching.idallen.com/cst8177/14w/notes/data/assignment09do.sh
[assignment09]$ curl -A mozilla "$url" >do.sh
[... make sure you scroll right to read the full web URL above ...]
[... various download statistics print here ...]

[assignment09]$ fgrep -i 'error' do.sh    # make sure no errors (no output)
[assignment09]$ head -n1 do.sh            # make sure it's a shell script
#!/bin/sh -u

5. Become the root user (if not already root) and, as shown below, use sh to run the do.sh script you just downloaded to CentOS as the root user with the USER environment variable set to your own CLS account userid. (Do not use abcd0001; use your own.) Make sure you run the script as the root user.
6. This Fetch program will connect from CentOS to the CLS using your account name in the USER variable. It will copy files from CentOS to your assignment09 directory on the CLS. It will then run the checking program on the CLS to check your work. You will need to answer one question about your IP address, and then wait and type in your CLS password, as shown below.

Your actions will look something like the following, running as the root user, but put your own userid in the USER variable not abcd0001:

[root@abcd0001 assignment09]# whoami
root                                                    # must be root
[root@abcd0001 assignment09]# USER=abcd0001 sh do.sh    # use your *own* userid *not* abcd0001
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abcd0001: FETCH version 3.  Connecting to CLS as USER='abcd0001' using ssh
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abcd0001: Use local Algonquin IP cst8177-alg.idallen.ca [y/N/?]? n
abcd0001: Please wait; using ssh to connect to user 'abcd0001' on cst8177.idallen.ca ...
*** COURSE LINUX SERVER ***
abcd0001@cst8177.idallen.ca's password:         # enter your CLS password
---------------------------------------------------------------------------
idallen-ubuntu assignment09fetch_server.sh version 6 run by abcd0001.
Please wait; collecting info from abcd0001 Virtual Machine
---------------------------------------------------------------------------
VM files collected into CST8177-14W/Assignments/assignment09/abcd0001.tar.bz on CLS.
Now running checking program for abcd0001 on CLS:
[... checking program output appears here ...]

5.2 Part II - Check and SubmitIndex

When you are done with your assignment, you need to run the checking program one last time on the CLS (not from CentOS) and submit the output file, as follows:

Do all this on the Course Linux Server when you are ready to submit:

1. There is a Checking Program named assignment09check in the Source Directory on the CLS. Create a Symbolic Link to this program named check under your new assignment09 directory on the CLS so that you can easily run the program to check your work and assign your work a mark on the CLS. Note: You can create a symbolic link to this executable program but you do not have permission to read or copy the program file.

2. Execute the above “check” program on the CLS using its symbolic link. (Review the Search Path notes if you forget how to run a program by pathname from the command line.) This program will check your fetched CentOS work, assign you a mark, and display the output on your screen. (You may want to paginate the long output so you can read all of it.)

   Remember: The checking program does not fetch new files to the CLS from your CentOS VM. You must run the Fetch program on your CentOS VM to update the fetched files on the CLS so that the checking program can mark them on the CLS.

   You may run the “check” program as many times as you wish, to correct mistakes and get the best mark. Some task sections require you to finish the whole section before running the checking program at the end; you may not always be able to run the checking program successfully after every single task step.

3. When you are done with checking this assignment, and you like what you see on your screen, redirect the output of the Checking Program into the text file assignment09.txt under your assignment09 directory on the CLS. Use the exact name assignment09.txt in your assignment09 directory. Case (upper/lower case letters) matters. Be absolutely accurate, as if your marks depended on it. Do not edit the file.

   • Make sure the file actually contains the output of the checking program!
   • The last text line of the file should begin with: YOUR MARK for
   • Really! MAKE SURE THE FILE HAS YOUR MARKS IN IT!

4. Transfer the above assignment09.txt file from the CLS to your local computer and verify that the file still contains all the output from the checking program. Do not edit this file! No empty files, please! Edited or damaged files will not be marked. You may want to refer to your File Transfer notes.

   • Make sure the file actually contains the output of the checking program!
   • The last text line of the file should begin with: YOUR MARK for
   • Really! MAKE SURE THE FILE HAS YOUR MARKS IN IT!

5. Upload the assignment09.txt file under the correct Assignment area on Blackboard (with the exact correct name) before the due date. Upload the file via the assignment09 “Upload Assignment” facility in Blackboard: click on the underlined assignment09 link in Blackboard. Use “Attach File” and “Submit” to upload your plain text file.

   No word-processor documents. Do not send email. Use only “Attach File”. Do not enter any text into the Submission or Comments boxes on Blackboard; I do not read them. Use only the “Attach File” section followed by the Submit button. If you need to comment on any assignment submission, send me email.

   You can upload the file more than once; I only look at the most recent. You must upload the file with the correct name; you cannot correct the name as you upload it to Blackboard.

6. Verify that Blackboard has received your submission: After using the Submit button, you will see a page titled Review Submission History that will show all your submissions.

   1. Verify that your latest submission has the correct 16-character, lower-case file name beside the Attached Files heading.
   2. The Submission Field and Student Comments headings must be empty. (I do not read them.)
   3. Save a screen capture showing the uploaded file name. If there is an upload missing, you will need this to prove that you uploaded the file. (Blackboard has never lost a file.)

   You will also see the Review Submission History page any time you already have an assignment attempt uploaded and you click on the underlined assignment09 link.

   You cannot delete an assignment attempt, but you can always upload a new version. I only mark the latest version.

7. Your instructor may also mark files in your directory in your CLS account after the due date. Leave everything there on the CLS. Do not delete any assignment work from the CLS until after the term is over!

• I do not accept any assignment submissions by email. Use only the Blackboard Attach File. No word processor documents. Plain Text only.

• Use the exact file name given above. Upload only one single file of Linux-format plain text, not HTML, not RTF, not MSWord. No fonts, no word-processing. Linux plain text only.

• NO EMAIL, WORD PROCESSOR, PDF, RTF, or HTML DOCUMENTS ACCEPTED.

• No marks are awarded for submitting under the wrong assignment number or for using the wrong file name. Use the exact 16-character, lower-case name given above.

• WARNING: Some inattentive students don’t read all these words. Don’t make that mistake! Be exact.

READ ALL THE WORDS. OH PLEASE, PLEASE, PLEASE READ ALL THE WORDS!