Mid Term

Question 1

What command would you use to keep a record of every command you type and the output of those commands?

Answer 1

script

Question 2

What key would you press to get the last command you typed?

Answer 2

up arrow

Question 3

How do you abort a running program?

Answer 3

Control C

Question 4

What would you type at the command line to get the man page for the ls command?

Answer 4

man ls

Question 5

How do you get the next screenfull when using man?

Answer 5

hit the Space bar

Question 6

How do you exit the man program?

Answer 6

hit q

Question 7

What is the other program, besides man, that you can use to get help?

Answer 7

info

Question 8

Name the three whitespace characters.

Answer 8

Space, Tab and newline (Enter or Return)

Question 9

If you wanted to use one of the characters that have special meaning to Unix in a filename, what TWO things could you do?

Answer 9

put a backslash in front of it or quote it

Question 10

What would you type on the command line if you wanted to go to the directory /courses?

Answer 10

cd /courses

Question 11

What would you type at the command line to see what directory you are currently in?

Answer 11

pwd

Question 12

What would you type at the command line to see ALL the files in the directory named /home/ghoffman?

Answer 12

ls -a /home/ghoffman

Question 13

What would you type at the command line to print to the screen the contents of the file named memo.txt?

Answer 13

cat memo.txt

Question 14

What would you type at the command line to delete the file named memo.txt?

Answer 14

rm memo.txt

Question 15

What would you type at the command line to create a directory named work?

Answer 15

mkdir work

Question 16

What would you type at the command line to copy the file named memo.txt to memo.bak?

Answer 16

cp memo.txt memo.bak

Question 17

What would you type at the command line to move the file named memo.txt into the directory named work?

Answer 17

mv memo.txt work

Question 18

What would you type at the command line if you wanted to see the value of the variable SHELL?

Answer 18

echo $SHELL

Question 19

What would you type at the command line if you wanted to know the network name of the Unix computer you were using?

Answer 19

hostname

Question 20

Name one of the two pager programs that allow you to read a long file one screenful at a time.

Answer 20

more or less

Question 21

If you started typing the name of a file on the command line and wanted Unix to supply the rest, what would you do?

Answer 21

hit the Tab key

Question 22

What would you type at the command line if you wanted to find all lines in the file results.txt that contained the word “homework”?

Answer 22

grep homework results.txt

Question 23

What would you type at the command line if you wanted to find all lines in the file results.txt that DID NOT contain the word “homework”?

Answer 23

grep -v homework results.txt

Question 24

What would you type at the command line if you wanted to see the FIRST 10 lines of the file log.txt?

Answer 24

head log.txt

Question 25

What would you type at the command line if you wanted to see the LAST 10 lines of the file log.txt?

Answer 25

tail log.txt

Question 26

What would you type at the command line if you wanted to see all the lines in the file results.txt in sorted order?

Answer 26

sort results.txt

Question 27

What would you type at the command line if you wanted to see all the lines in numbers.txt sorted in REVERSE NUMERIC order?

Answer 27

sort -nr numbers.txt

Question 28

If you saw the following prompt, what USER was logged into the machine? it244gh@vm75:/courses/it244/s19/ghoffman$

Answer 28

it244gh

Question 29

If you saw the following prompt, what was the HOSTNAME of the machine? it244gh@vm75:/courses/it244/s19/ghoffman$

Answer 29

vm75

Question 30

If you saw the following prompt, what is your CURRENT DIRECTORY? it244gh@vm75:/courses/it244/s19/ghoffman$

Answer 30

/courses/it244/s19/ghoffman

Question 31

What would you type at the command line if your wanted to find all lines in the file red_sox.txt that had the word "Win", but NOT the word "Rays"?

Answer 31

grep Win red_sox.txt | grep -v Rays

Question 32

What would you type at the command line if your wanted to find all lines in the file red_sox.txt that had the word "Win", but NOT the word "Rays", and have the lines sorted alphabetically?

Answer 32

grep Win red_sox.txt | grep -v Rays | sort

Question 33

What command would you use to find the date and time?

Answer 33

date

Question 34

What program would you use to find where the program file for tar is located?

Answer 34

which or whereis

Question 35

What would you type at the command line if you wanted to find all files with "link" as part of their name?

Answer 35

locate link

Question 36

What command would you use to find out all the users currently logged on to the machine you are using?

Answer 36

finger or who

Question 37

What would you type at the command line if you wanted to find out all you could about the user with account name wombat?

Answer 37

finger wombat

Question 38

What is the name of the directory at the top of the Unix filesystem?

Answer 38

root

Question 39

What symbol is used to represent the top of the Unix filesystem?

Answer 39

/

Question 40

What do you call the directory directly above your current directory?

Answer 40

the parent directory

Question 41

What do you call a directory inside your current directory?

Answer 41

a child directory

Question 42

What would you type at the terminal to go to the top of the hierarchical file system?

Answer 42

cd /

Question 43

Can you have two files with the same name in the same directory?

Answer 43

no

Question 44

Can you have two files named memo.txt and Memo.txt in the same directory?

Answer 44

yes. the filename are different because Unix is case sensitive

Question 45

Does Unix recognize filename extensions?

Answer 45

no

Question 46

What directory are you in when you first log in to a Unix machine?

Answer 46

your own home directory

Question 47

In what directory is YOUR home directory located?

Answer 47

/home

Question 48

What do you call a text file containing Unix commands that are run just before the shell gives you a prompt?

Answer 48

a startup file

Question 49

Where are the files mentioned above located?

Answer 49

in your home directory

Question 50

If you entered the following at the command line, where would you be? cd ~

Answer 50

your home directory

Question 51

If you entered the following at the command line, where would you be? cd ~ghoffman

Answer 51

in the home directory of ghoffman

Question 52

What does the . (dot) in your current directory mean?

Answer 52

your current directory

Question 53

What does the .. (dot dot) in your current directory mean?

Answer 53

the parent directory of your current directory

Question 54

What do you call the list of directories you must go through to get from one directory to another?

Answer 54

a path

Question 55

What directory is the starting point for EVERY absolute path?

Answer 55

the root directory

Question 56

What directory is the starting point for a relative path?

Answer 56

the current directory

Question 57

What character is used to separate directory and filenames in a path?

Answer 57

/

Question 58

By default, which account is the owner of a file or directory?

Answer 58

the account that created it

Question 59

Name the three types of access permissions.

Answer 59

read, write and execute

Question 60

Name the three categories of accounts which are used in assigning access permissions.

Answer 60

owner, group, everyone else

Question 61

Who can change the access permissions on a file or directory?

Answer 61

only the owner

Question 62

What would you enter on the command line if you wanted to see the access permissions of entries in your current directory?

Answer 62

ls -l

Question 63

What is the name of the command you would use to change the access permissions for a file or directory?

Answer 63

chmod

Question 64

Three numbers can be used to specify access permissions when using the command above. Each of these numbers can only be in a certain range. What is the maximum and minimum for each of these three numbers?

Answer 64

0 to 7

Question 65

If the file work.sh has the permissions given below, what could the owner of the file do? -rwxr-x--x 1 ghoffman grad 0 Sep 27 11:08 work.sh

Answer 65

read, write and execute

Question 66

For the same file, what could the group do?

Answer 66

read and execute

Question 67

For the same file, what could every other account do?

Answer 67

only execute

Question 68

What is the name of the account that can do ANYTHING on a Unix or Linux system?

Answer 68

root

Question 69

If you have read permission on a directory, what can you do in it?

Answer 69

run ls on the directory to list its contents

Question 70

If you have read permission on a directory, can you read the files in that directory?

Answer 70

no, you need read permission on each file

Question 71

What permission on a directory allows you to create, delete or rename anything in that directory?

Answer 71

write permission

Question 72

If you have write permission on a directory do you have write permission on the files it contains?

Answer 72

no, you need write permission on each file

Question 73

If you have execute permission on a directory what can you do?

Answer 73

cd into that directory

Question 74

What does Unix call a file that points to another file or directory?

Answer 74

a link

Question 75

What are the two kinds of links?

Answer 75

hard links and soft links

Question 76

What kind of link is used most often?

Answer 76

soft links

Question 77

What command would you use to create a soft link named "home" in your current directory to YOUR home directory?

Answer 77

ln -s ~ home

Question 78

What symbols come before an option on the command line?

Answer 78

- or --

Question 79

What is the program the collects the characters you type at the command line?

Answer 79

tty device driver

Question 80

When does this program send what you have typed at the command line to the shell?

Answer 80

when you hit Enter on a PC or Return on a Mac

Question 81

What does the PATH shell variable contain?

Answer 81

the list of directories the shell must search to find the file to run a command

Question 82

Does the shell check that a program gets the arguments or options it needs?

Answer 82

no, that is the responsibility of the program itself

Question 83

If you wanted to run the executable script work.sh in your current directory without using bash, what would you type at the command line?

Answer 83

./work.sh

Question 84

What is a process?

Answer 84

a running program

Question 85

What does the shell do after it runs the program the user entered at the command line?

Answer 85

it goes into an inactive state called sleep

Question 86

What does a program do JUST BEFORE it stops running?

Answer 86

it sends an exit status to the shell

Question 87

What does an exit status of 0 mean?

Answer 87

it means that the program encountered no errors

Question 88

By default, where does Standard Input come from?

Answer 88

the keyboard

Question 89

By default, where does Standard Output go?

Answer 89

to the screen

Question 90

If you wanted to send the output of ls to the file dir_listing.txt, what would you enter at the command line?

Answer 90

ls > dir_listing.txt

Question 91

If you wanted the program do_something to take input from the file data.txt what would you write at the command line?

Answer 91

do_something < data.txt

Question 92

If you wanted to run the program do_something but have no output appear on the screen, or be sent to a file, what would you type at the command line?

Answer 92

do_something > /dev/null

Question 93

If you wanted to add the output of who to the file logged_on.txt what would you type at the command line?

Answer 93

who >> logged_on.txt

Question 94

If a program does not specify where its input comes from, where would it come from?

Answer 94

from Standard Input

Question 95

If a program does not specify where its output goes to, where would it go?

Answer 95

to Standard Output

Question 96

Where does a program send its error messages?

Answer 96

to Standard Error