Question

Linux Operation

For the following exercises, ensure the following regarding the student1 and student2 accounts:

• The home directories are /home/student1 and /home/student2
• The student accounts are in the students group
• The umask for the student1 and student2 accounts is: 022, (should be by default)
• The “student” account home directories have 755 permissions.
• Execute steps in the “Lab 2 setup supplement” document on D2L to get the above set up.

Also note that, the term “home directory” below, if not specified in detail, refers to the home directory of the current user (e.g. /home/student1 for the student1 account). This does not specify just the “/home” directory.

*** On the lab answers – be sure you use the form fields, so that your answers are show in red ***

SECTION 1 – Absolute/Relative Paths, Files and Directories:

1. Log into the student1 account. Enter the command to tell you what your current directory is:

     .

Now cd to the /tmp directory. Enter two commands, which will change your directory to the home directory for student1:

      and      

Verify these two commands work by displaying your current directory after each one is run.

2. Ensure you are in your home directory for student1. List the contents of the /tmp directory using an absolute path name:      .

List the contents of the /tmp directory using a relative path name:      .

After listing the contents of a directory, does your present working directory change?      .

What command changes your present working directory?      .

3. Ensure you are in your home directory for student1. Change your current directory to the root (/) directory. What command did you use:      .
4. Enter the cd ~ command. What directory are you now in?         .

Explain what “~” represents:      .

5. Ensure you are in your home directory for student1. Create a file called labfile1 with the touch command in the /tmp directory using a relative path name. What command did you use:

     .

Create another file called labfile2 with the touch command in the /tmp directory using an absolute path name. What command did you use:        .

6. What is the file size of files created with the touch command?        .

Now touch one of these files again. What, if anything is different in the file’s characteristics?        .

7. Ensure you are in your home directory for student1. Using the echo command with output redirection, and an absolute path, add 10 lines to the /tmp/labfile1 file. Make each line just one word - line1, line2, through line10. What is the new file size of the /tmp/labfile1 file?      .

In what storage units are files displayed in unix?        .

Ensure you are in your home directory for student1. Use the tail command and a relative path to display the last 5 lines of the /etc/passwd file. What command did you use:        .

Ensure you are in your home directory for student1. Use the head command and an absolute path to display the first 5 lines of the /etc/group file. What command did you use:        .

8. Ensure you are in your home directory for student1. Create a new subdirectory in your home directory called subdir1. What command did you use:        .

Change your current directory to the subdir1 directory using a relative pathname. What command did you use:      .

Change back to your home directory for student1. Create a file called labfile3 in this subdir1 directory using the touch command with a relative pathname. What command did you use:

     .

9. Ensure you are in your home directory for student1. Execute the following commands: ls –al subdir1 and ls –ald subdir1. What is the difference between these 2 commands?

     .

Answer 1

To create user with 022 permissions by default:
You can setup umask in /etc/bashrc or /etc/profile file for all users. By default most Linux distro set it to (022). Open /etc/profile or ~/.bashrc file, enter:
# vi /etc/profile

sudo useradd -m -d /home/student1 student1

sudo useradd -m -d /home/student2 student2

sudo su student1

sudo usermod -a -G www-data student1

sudo chmod -R 755 /home/student1
sudo chmod -R 755 /home/student2

sudo su student1
cd ~/.
/home/student1

cd /tmp
cd ~/.
cd /tmp
ls -ltr
cd /

cd /tmp
touch labfile1
touch /tmp/labfile2

cd /home/student1
echo line1, line 2, line3 , line4 , line 5, line 6 , line 7, line 8, line 9, line 10 >> /tmp/labfile1

ls -ltr /tmp

ext4

cd /home/student1
tail -n 5 /etc/passwd
head -n 5 /etc/passwd
mkdir subdir1
cd subdir1
cd .
cd subdir1
mkdir labfile3
ls –al subdir1
dipalys files in directory
ls –ald subdir1
difplays directory information