Topic3: GNU and Unix Commands

Question 1

South Columbus

Question 2

1: Master Bathroom Toilet

effect of the egrep command when using the -v option

Answer 2

outputs non-matching lines

Question 3

2 : Master Bathroom Bath

with FHS what directory are man pages found

Answer 3

/usr/share/man

Question 4

3: Master Bath Round Mirror 1

file in user home directory used to store Bash history

Answer 4

.bash_history

Question 5

4: Master Bath Sink 1

Bash env var defines in which file the user history is stored when the user history is stored when exiting a Bash process

Answer 5

HISTFILE

Question 6

5: Master Bath Round Mirror 2

user accidentally created subdirectory \dir in his home directory. Which of the following commands will remove the directory?

Answer 6

rmdir ~/\dir

Question 7

6: Master Bath Sink 2

signal sent to a process when the key combination CTRL+C is pressed on the keyboard

Answer 7

SIGINT

Question 8

7: Master Bath Window

vi editor how can commands such as moving the cursor or copying lines into the buffer be issued multiple times or applied to multiple rows

Answer 8

by specifying the number right in front of a command such as 4l or 2yj.

Question 9

8: Master Bath Radiator

Which grep command will print only the lines that do not ed with a / in the file foo.

Answer 9

grep -v ‘/$’ foo

Question 10

9: Master Bath Door

commands that can be used to determine how long the system has been running

Answer 10

uptime

top

Question 11

10: Landing outside Master Bath Door

which characters can be combined with a separator string in order to read from the current input source until the separator string, that is on a separate line and without and trailing spaces is reached

Answer 11

«

Question 12

11: Master Bedroom Closet

cmd will NOT update the modify timestamp on the file /tmp/myfile.txt

Answer 12

file /tmp/myfile.txt

Question 13

12: Master Bedroom Window

which commands replace each occurrence of ‘bob’ in the file letter with ‘Bob’ and writes the result to the file newsletter

Answer 13

sed ‘s/bob/Bob/g’ letter > newsletter

Question 14

13: Master Bedroom Dresser

What does the + symbol mean in the following grep regular expression

grep ‘^d[aei]+d$’ /usr/share/dict/words

Answer 14

Match the preceeding character set ([aei]) one or more times

Question 15

14: Master Bedroom Dresser

vi editor which cmd will copy the current line into the vi buffer

Answer 15

yy

Question 16

15: Master Bedroom Master Bedroom Mirror

In Bash, inserting 1>&2 after a cmd redirects

Answer 16

standard output to standard error

Question 17

16: Master Bedroom Window (facing street)

what command can be used to create a USB storaage media from a disk image

Answer 17

dd

Question 18

17: Master Bedroom Computer Desk

which of the following commands prints all files and directories within the /tmp directory or its subdirectories that are also owned by the user root

Answer 18

find /tmp -user root -print

find /tmp -user root

Question 19

18: Master Bedroom door
Command that determines the type of file by using a definition database file that contains information about all common file types

Answer 19

file

Question 20

19: Crawl Space

default nice level when a process is started using the nice command

Answer 20

10

Question 21

20: Washer Dryer

editing in vi and file changed due to another process. without exiting vi how can the file be reopened for editing with the new content

Answer 21

:e

Question 22

21: Stairs

regarding nice -5 /usr/bin/prog what is the current nice level

Answer 22

5

Question 23

22. Living Room Couch 1

cmd searches down a particular number of subdirectories

Answer 23

-maxdepth

Question 24

23. Living Room Couch 2

max niceness level a regular user can assign to a process with the nice command when executing a new process

Answer 24

19

Question 25

24. Stairs (Down) vi editor save opened document and exits the editor

Answer 25

esc ZZ esc :wq!

Question 26

25. Bottom Floor Closet what is true about cmd foo 1> bar

Answer 26

stdout from cmd foo overwrites file bar

Question 27

26: Bottom Floor Door character added to end of a cmd runs that cmd in background as a child process of current shell

Answer 27

&

Question 28

27: Bottom Floor Futon valid reason to run a command in the background of your shell

Answer 28

cmd has to be run immediately but the user needs to log out

Question 29

28. Bottom Floor TV Hutch purpose of bash built in export cmd

Answer 29

sets up env vars for apps

Question 30

29: Bottom Floor Window cmd will print last 10 lines of a text file to standard output

Answer 30

tail -n 10 filename

Question 31

30: Bottom Floor Crib commands is used to change options and positional parameters

Answer 31

set

Question 32

31: Bottom Floor Bathroom Window diff between i and a cmds in vi

Answer 32

i (insert) inserts text BEFORE the current cursor position a (append) inserts text AFTER the cursor

Question 33

32: Bottom Floor Bathroom Shower cmd moves and resumes in background that last stopped shell job

Answer 33

bg

Question 34

33. Bottom Floor Bathroom Toilet for sed -e "s/a/b" /tmp/file > /tmp/file why is the /tmp/file empty afterwards

Answer 34

When the shell establishes the redirection it OVERWRITES the target file before the redirected cmd starts and opens it for reading

Question 35

34. Bottom Floor Sink when starting a program with nice cmd without any additional params which nice level is set for the resulting process

Answer 35

10

Question 36

35. Bottom Floor Mirror cmd prints a list of username (first column) and their primary group (fourth column) from the /etc/passwd file

Answer 36

cut -d : -f 1,4 /etc/passwd

Question 37

36. Bathroom Door cmd reduce all consecutive spaces down to a single space

Answer 37

tr -s ''< a.txt > b.txt

Question 38

36. Bottom FLoor Walkin Closet cmd displays list of all background tasks running in current shell

Answer 38

jobs

Question 39

37. Stairs (up) var defines the directories that Bash shell searches for executable cmds

Answer 39

PATH

Question 40

38. Living Room Closet 1 immediately after deleted 3 lines of text in vi and moving cursor to diff line which single char cmd will insert deleted content below current line

Answer 40

p (lowercase)

Question 41

39. Living Room Closet 2 cmd will send output from the program myapp to both stdout and the file - file 1

Answer 41

myapp | tee file1.log

Question 42

40. Living Room Closet 3 valid stream redirection operators with Bash

Answer 42

< <<< >

Question 43

41. Living Room Bathroom Mirror when given cmd line echo "foo bar" | tee bar | cat. what output is created

Answer 43

foo bar

Question 44

42. Living Room Bathroom Sink signal missing from following command that is commonly used to instruct a daemon to reinitialize itself including reading config files killall -s ______ daemon

Answer 44

HUP SIGHUP 1

Question 45

43. Living Room Bathroom Toilet output of cmd. echo "Hello World" | tr -d aieou

Answer 45

Hll Wrld

Question 46

44. Living RoomBig Door Right Side following commands display contents of gzip compressed tar archive

Answer 46

tar ztf archive.tgz

Question 47

45. Living Room Big Door Left Side shell directions will write standard output and standard error output to a file named filename

Answer 47

>filename 2>&1

Question 48

46. Living Room Big Window 1 ? symbol with regular expression

Answer 48

match preceeding qualifier zero or one times

Question 49

47. Living Room Computer Desk shell cmd used to continue background execution for a suspended cmd

Answer 49

bg

Question 50

48. Living Room Big Window 2 cmd will generate a list of user names from /etc/passwd with login shell

Answer 50

cut -d: -f1,7 /etc/passwd

Question 51

49. Living Room Radiator default action of split cmd on input file

Answer 51

break the file into new files of 1,000 line pieces each

Question 52

50. Kitchen Refriferator cmd kils process with PID 123 but allows the process to "clean up" before exiting

Answer 52

kill -TERM 123

Question 53

51. Kitchen Sink /etc/_______ file lists currently mounted devices

Answer 53

mtab

Question 54

52. Kitchen Table cmd used in linux env to create new directoor

Answer 54

mkdir

Question 55

53. Kitchen Chairs from Bash shell which of the following cmds directly executes the instruction from the file /usr/local/bin/runme.sh without starting subshell

Answer 55

source /usr/local/bin/runme.sh ./usr/local/bin/runme.sh

Question 56

54. Living Room Table cmd sets bash var TEST with content FOO

Answer 56

TEST="FOO"

Question 57

55. Living Room Fire Place what happens after issuing cmd vi without any additional params

Answer 57

vi starts in cmd mode and opens a new empty file

Question 58

56. Living Room Painting your trying to make a hard link to an ordinary file bit ln returns error - what would cause that?

Answer 58

The source and target are on different file systems