PS

aux

#shows all running proccess

au jf  

#shows running procces and tree

How do you change the full name of the user?

(2 ways)

1. edit the /etc/passwd and manually enter

2. use the chfn (no options if current user)

chsh user

change the shell to /usr/sbin/nologin

or change the shell to 

/bin/false

The second way prevents login period, the first way states that the account is currently not available.

usermod -aG

-a = append

-G = groups (can change multiple)

centOS = firewalld

Ubuntu = iptables

cat /etc/lsb-release

cat /etc/debian_version

uname -a

1. I for insert

2. A for append and insert on the current line

3. O for append and insert on the next line

yy - yank the entire current line

p - paste after the cursor

P - paste before the cursor

u - undoes any change made

U - undoes a change made to the current line

/test

Retype /test

How would you search your whole Linux file system to find the file ping.txt?

How would you ignore the case of the letters in the search?

Which variable could you use to list every file except ping.txt?

find / -name "ping.txt"

use -iname

add -not

find / -mtime -1

or 1 for greater than a day ago

What does this function do?

cp -rf .. .

Creates a copy of all the conents in a folder one tree up into the current folder.

cp = Copy

-recursive

-force

What would this command do?

tar -cvzf data_backup.tar.gz data

Tar = tape backup

-c compress

-v verbose

-z zip

-f files

data = destination directory

tar tvf file

t = list

v = verbose

f = file

tar zxvf ../file /destination

z - uncompress

x - extract

v - verbose

f - file

How would you set a file to be immutable?

How would you set a file to only allow users to append it?

chattr +i file

chattr +a file

TOP - shows all running and sleeping processes

HTOP - Better and needs to be installed

use to add to yum library yum install epel-release

free - shows free memory add -m for

df -h   //  Shows Mounted drives

df -hTi  // Shows Inode information

du -sch /var/* - Useful for finding directories that are using too much space

yum install -y yum-utils

yumdownloader appname

What does this command do?

yum repolist all

What does this command do?

yum --enablerepo= install debuginfo

Lists enabled and disabled repositories install on your system.

Would install the debug repository and enable it.

How do you list the PATH and how would you add a directory to the PATH?

Then how to you save your changes so that they work in your next terminal session?

env | grep PATH

export PATH=$PATH:/dir/dir

add your PATH=$PATH:/dir/dir:/dir/dir to either

.bashrc or .profile in your ~ directory

How do you create a new user with proper regular syntax?

What are two required steps after that?

useradd -d /home/user/testuser testuser

You must then Manually create the home directory

mkdir /home/user/testuser

chown testuser:testuser testuser

(from /home)

adduser testuser

Adds the home dir with the appropriate group

userdel testuser

Remove the user's home directory

How do you add a user group?

(3 ways)

addgroup test1

groupadd test1

vim /etc/groups

visudo

Then duplicate the root user line with the username instead of root.

If you wanted to place a system wide variable or script available for all users what file would you place it in?

(ubuntu, centos)

Ubuntu

/etc/bash.bashrc

Centos

/etc/bashrc

What steps do you need to take to add a new user manually?

5 steps

Add the user to VIPW

Add the new user's group with VIGR

Create the home directory & set the file permissions for the new user

Copy the skel directory to the new user's directory.

Set the user passwd

Append

PATH=$PATH:/home/user/

Set

PATH=/home/user/

export VARIABLE

no

add the variable to:

/etc/profile

Explain this command:

ls f[igh][lfz]e*.???

This command prints the current directory list:

starting with the letter f,

the second character being either i,g, or h

the 3rd character being either l, f, or z

the 4th character being e

the 5th+ characters being anything

and the file extension being exactly 3 digits of anything character

*remember that all of this is case sensitive*

*remember you can use [A-Z] to search for characters in a range*

How can you ignore a variable in a string that uses a $?

For example

echo "The cheeseburger is going to cost you $5.00"

Use a \ in front of $

for example

echo "The cheeseburger is going to cost you \$5.00"

a command contains a

1. command

and then you can add:

2. options ie -L  which tells the command how to do something

3. arguments which tells the command how to do it

ie find -iname "profile.bash"

sudo su

You then change the Root password and you may then login.

whereis passwd

for the application passwd

n for next

N for previous