Linux Questions

Question 1

$

Answer 1

variable Use $ to retrieve the value of a variable, but not to create or change it.

Question 2

/etc/password

Answer 2

contains all the accounts on the system -log in name, password info, user id, group id. etc….

Question 3

ln

Answer 3

utility is used to create hard links

Question 4

ln -s

Answer 4

utility is used to create soft (or symbolic) links

Question 5

The -i option to ls

Answer 5

prints out in the first column the inode number

Question 6

cat

Answer 6

Used for viewing files that are not very long; it does not provide any scroll-back.

Question 7

tac

Answer 7

Used to look at a file backwards, starting with the last line.

Question 8

less

Answer 8

Used to view larger files because it is a paging program; it pauses at each screen full of text, provides scroll-back capabilities, and lets you search and navigate within the file. Note: Use / to search for a pattern in the forward direction and ? for a pattern in the backward direction. (An older program named more is still used, but has fewer capabilities.)

Question 9

tail

Answer 9

Used to print the last 10 lines of a file by default. You can change the number of lines by doing -n 15 or just -15 if you wanted to look at the last 15 lines instead of the default.

Question 10

head

Answer 10

The opposite of tail; by default, it prints the first 10 lines of a file.

Question 11

Displays Linux system information

Answer 11

uname -a

Question 12

Displays kernel release information

Answer 12

uname -r

Question 13

show which version of redhat is installed

Answer 13

cat /etc/redhat-release

Question 14

show how long the system has been running + load

Answer 14

uptime

Question 15

show system host name

Answer 15

hostname -I

Question 16

show system reboot history

Answer 16

last reboot

Question 17

show current date and time

Answer 17

date

Question 18

show month;s calendar

Answer 18

cal

Question 19

Quotes that contains strings and any variable or commands within them get evaluated or acted on

Answer 19

“double quotes”

Question 20

Anything within these quotes gets treated literally, disables any special character functionality

Answer 20

‘single quotes’

Question 21

This character disables any special character functionality that immediately follows it

Answer 21

\ (ie) $3.00 prints as $3.00 -won’t try to evaluate the 3.00 as a variable

Question 22

_________ quotes around spaces or an escape character preceding a space will be treated literally

Answer 22

double quotes (or both double and single quotes)

Question 23

\ (before”enter”)

Answer 23

Allows us to extend the command to multiple lines- this escapes out the enter key as the end of the command

Question 24

________________What to do?
________________ How to do it?
________________ What to do it on?

Answer 24

Command
-Options
Arguments

Question 25

searches a local database of files and folders looking for items that match the search criteria.

Answer 25

locate

Question 26

searches the file system for files that match the search criteria. _____/path/to/folder -name * if we don't provide a directory here, the command will start in the directory we are in. can give it part of the file name '*.xml'

Answer 26

find

Question 27

locates binary source and/or man pages for a command

Answer 27

whereis

Question 28

add a new user command?

Answer 28

adduser or useradd

Question 29

a new user will typically own everything ______ and ______ the new users home directory.

Answer 29

including and beneath

Question 30

Change ownership of the file named myfile to student use:

Answer 30

chown student myfile

Question 31

changes the group ownership

Answer 31

chgrp

Question 32

change the ownership and group ownership of many files at the same time, (only be used by the root user)

Answer 32

chown

Question 33

ability to run commands as the root user without knowing the root password.

Answer 33

sudo

Question 34

sudo users and which commands they can use are kept here.

Answer 34

/etc/sudoers

Question 35

command that lets you edit the sudoers file

Answer 35

visudo

Question 36

Allows us to extend the command to multiple lines- escapes out the enter key

Answer 36

\ (before"enter")

Question 37

disk usage command

Answer 37

df (disk free)

Question 38

disk free human friendly

Answer 38

df -h

Question 39

disk free inodes report

Answer 39

df -i

Question 40

du

Answer 40

displays the number of disk blocks used by directories

Question 41

displays the number of disk blocks used by directories

Answer 41

du

Question 42

encoding information using fewer bits

Answer 42

data compression

Question 43

compression utility on Linux - works on a single file

Answer 43

gzip

Question 44

Changes ownership of the file named student to myfile

Answer 44

chown myfile student

Question 45

To compress a group of files you may have to _____

Answer 45

collect them first with ar

Question 46

other compression utilities on Linux

Answer 46

zip, unzip | bzip 2, bunzip2

Question 47

backs up part or all of your files or filesystems

Answer 47

tar

Question 48

tar will compress/uncompress if you use the ___ option

Answer 48

z

Question 49

schedules a (1) job for future execution

Answer 49

at

Question 50

schedules any number of jobs each at repeated times in the future

Answer 50

crontab

Question 51

files that an administrator uses to control which users can use the cron and at commands

Answer 51

at. deny at. allow cron. deny cron. allow

Question 52

A file is stored in _____________ and then executed at the appropriate time by the ___ daemaon.

Answer 52

/var/spool/at/somename | atd

Question 53

``` shows job number assigned to you (using at) #what is in the queue ```

Answer 53

atq

Question 54

removes at job

Answer 54

atrm (then number of job ie 2)

Question 55

In the past ________ was the packet manager of choice.

Answer 55

rpm (Red Hat Package Manager)

Question 56

_____ extends the capabilities of rpm with additional features that simplifies package management

Answer 56

yum (Yellowdog Updater Modified)

Question 57

One of the original text editors for Unix-like operating systems

Answer 57

vi

Question 58

Successor to the vi text editor. Offers the same functionality plus extra features

Answer 58

vim

Question 59

insert text under cursor in vim

Answer 59

i

Question 60

writes the vim/vi files out to disk without quitting

Answer 60

:w

Question 61

writes the vim/vi files out to disk (save), then quit (same as zz)

Answer 61

:wq

Question 62

to append text to line in vim

Answer 62

shift a

Question 63

to start an empty file in vim or vi, type:

Answer 63

vim (or vi)

Question 64

Any keystroke that is a command for modifying script puts you in insert mode. Press _________ to go to ________ mode in vim.

Answer 64

escape, command

Question 65

quit vim/vi without saving (ex command)

Answer 65

q!

Question 66

When you are in command mode in vim, the following commands will move you into insert or append mode.

Answer 66

A move cursor to end of line I move cursor to begining of a line O open a line above where cursor is located a move cursor to just after current character i move cursor to just before current character o open a line below where cursor is located

Question 67

reads first 20 lines of somefilename

Answer 67

head -n 20 somefilename

Question 68

reads first 10 lines of somefilename

Answer 68

head somefilename

Question 69

reads last 20 lines of somefile

Answer 69

tail -n 20 somefilename

Question 70

reads last 10 lines of somefile

Answer 70

tail somefilename

Question 71

use tail to follow a command as it gets updated example

Answer 71

tail -f /var/log/secure

Question 72

to stop a running tail

Answer 72

Ctrl + C

Question 73

to stop any command that is running at the command prompt

Answer 73

Ctrl + C

Question 74

grep

Answer 74

searches and prints out matches

Question 75

searches and prints out matches

Answer 75

grep

Question 76

grep < >

Answer 76

pattern

Question 77

grep < >

Answer 77

file to search

Question 78

grep ignore case

Answer 78

grep -i < file to search >

Question 79

used to send output of one command as input to another

Answer 79

pipe command |

Question 80

used to redirect standard output to new location

Answer 80

> (writes over) >> (appends)

Question 81

searches for lines that begin with a given word

Answer 81

grep -i '^republic' filename

Question 82

finds lines that begin with a certain character

Answer 82

grep '^[Aa]' filename

Question 83

finds lines that do not begin with a certain character

Answer 83

grep '^[^Aa]' filename

Question 84

finds lines with a certain second character (h)

Answer 84

grep '^.[h]' filename

Question 85

find lines with www followed by anything

Answer 85

grep 'www*' filename

Question 86

Changing user permissions to read and write only user

Answer 86

chmod 600 file or directoryname

Question 87

verify permissions

Answer 87

ls -l