(Unix/Linux Lesson 2)

{ cp, mv, rm, rmdir, cat, more, head, tail, grep, wc }

Before you get started

1. Use TargetUbuntu01 or whatever Unix/Linux server you have access too.

2. Login as user account "student" or whatever Unix/Linux account you have access to on the particular server.

cp (copy)

1. pwd - Shows you your current working patch (Where you are right now).
2. touch practice1.txt - This will create a zero-byte file for the purposes of testing.
3. cp practice1.txt practice2.txt
4. ls -lrt practice* - Show you the long listing of files sorted by ascending by time, all files starting with practice.

mv (Move)

1. mv practice1.txt practice3.txt
2. ls -lrt practice* - Show you the long listing of files sorted by ascending by time, all files starting with practice.
   • Notice practice1.txt is not displayed.

rm (Remove)

1. rm practice3.txt
2. ls -lrt practice* - Show you the long listing of files sorted by ascending by time, all files starting with practice.
3. touch practiceA.txt - create another file
4. touch practiceB.txt - create another file
5. touch practiceC.txt - create another file
6. ls -lrt practice* - Show you the long listing of files sorted by ascending by time, all files starting with practice.
7. rm practice* - remove all files that start with the word practice, using the wild card "*".
8. ls -lrt practice*

rmdir (Remove Directory)

First, we will create some directories and files that we will later remove.

1. mkdir folderA - mkdir folderA
2. mkdir folderB - mkdir folderB
3. touch folderA/fileA.txt - Create a practice file in folderA called fileA.txt
4. touch folderB/fileB.txt - Create a practice file in folderB called fileB.txt

Option 1:  rmdir (Remove Directory)

1. rmdir folderA
   • Notice you get a message saying the directory is not empty.
   • You will have to empty the directory before you can remove it.
2. cd folderA
3. ls -l
   • You will see fileA.txt that you will need to remove.
4. rm fileA.txt
   • This removes the file
5. cd ../
   • cd out of the directory
6. rmdir folderA
   • Now you can remove folderA, because it is empty.
7. ls -l | grep folderA
   • Do a long list of all file in the directory and search for anything called folderA

Option 2:  rm -rf (Remove Directory)

• -f, mean to force
• -r, mean to recursive remove a directory and its contents.
  

1. rm -rf folderB                          
   • Remove folderB and its' contents
2. ls -l | grep folderB | wc -l
   • Do a long listing, search for folderB, and count how times folderB is found.
   • Notice "0" is returned, because folderB is now gone.
3. Note
   • rm -rf is a very dangerous command.
   • Never, Never, Never issue rm -rf *, unless you absolutely need to issue this command.

Prep Work

1. cd
   • This will place you back in your home directory.
2. cp /etc/passwd PASSWD.TXT
   • You will see a file called PASSWD.txt

Option 1:  cat

1. cat PASSWD.TXT
   • Notice that the entire file will be printed to the screen.

   

2. clear
   • This command will clear your screen

Option 2:  more

First, we will create some directories and files that we will later remove.

1. more PASSWD.TXT
   • Press the <Enter> key to scroll line by line.
   • Press the <spacebar> to scroll page by page
2. clear
   • This command will clear your screen

This is what the output should look like

Option 3:  less

• less is the opposite of more.
• less is similar to more.
• less allows both backward and forward movement in a file.
• less does not have to read the entire file before starting.  (This is really handy for large files).

1. clear
2. less PASSWD.TXT
   • You will see output very similar to more.

   

3. Now search for the username "snort" by using the forward "/"
   • /snort

   

4. Type "q" to escape the less editor

Option 4:  head

• Output the first part of the file first.
• head by default shows 10 lines at a time.

1. clear
2. head PASSWD.TXT

   

3. clear
4. head -5 PASSWD.TXT
   • Show me the first 5 lines of the PASSWD.TXT file.

   

Option 5:  tail

• Output the last part of the file first.
• last by default shows 10 lines at a time.

1. clear
2. tail PASSWD.TXT

   

3. clear
4. tail -5 PASSWD.TXT
   • Show me the last 5 lines of the PASSWD.TXT file.

   

Command: grep

• grep, prints lines matching a certain pattern.
• grep <pattern> filename

1. clear
2. grep snort PASSWD.TXT
   • Search and display results for the pattern "snort" in the PASSWD.TXT file.

   

3. grep false PASSWD.TXT
   • Search and display results for the pattern "false" in the PASSWD.TXT file

   

4. grep -c false PASSWD.TXT
   • Count the number of results.

   

5. grep false PASSWD.TXT | wc -l
   • Count the number of results

   

Command: egrep

• egrep, prints lines matching a certain pattern.
• egrep '(pattern1|pattern2|pattern3)' filename

1. clear
2. egrep '(snort|student|instructor)' PASSWD.TXT
   • Search for snort, student and instructor

   

1. cat .lesshst
2. Capture the screen by the <Alt> button and <PrtScn> button at the same time.
3. Paste the screen in a word document
4. Upload to Moodle Lab 7 B.