Unix

Question 1

command for: list contents of current directory

Answer 1

ls

Question 2

command for: make a directory

Answer 2

mkdir

Question 3

command for move:

Answer 3

mv

Question 4

command for rename:

Answer 4

mv

Question 5

what would the command be to move text1 into directory files

Answer 5

mv text1 files

Question 6

command for changing to a directory:

Answer 6

cd

Question 7

command for printing current directory to the terminal:

Answer 7

pwd

Question 8

command to move to previous directory:

Answer 8

cd ..

Question 9

command to show contents of a file:

Answer 9

more

Question 10

command to copy:

Answer 10

cp

Question 11

command to remove:

Answer 11

rm

Question 12

command to remove a directory:

Answer 12

rmdir

Question 13

command to change security permissions:

Answer 13

chmod

Question 14

command to do a long list of files:

Answer 14

ls -l

Question 15

addition to ls if we want to see details of files and direcetories:

Answer 15

ls -l

Question 16

wildcard to match anything (to be read by shell):

Answer 16

*

Question 17

in file permissions what are u,g,o?

Answer 17

u = user
g = groups
o = the rest

Question 18

how would you see what permission groups you’re in?

Answer 18

groups

Question 19

in file permissions, what are r,w,x?

Answer 19

r = read
w = write
x = execute

Question 20

what symbol can be used for home directory?

Answer 20

~

Question 21

how can the home directory symbol be used to mean someone else’s home directory?

Answer 21

~theiruserid

Question 22

what does man -k do?

Answer 22

search manual for a following word

Question 23

what is the command to find someones username?

Answer 23

finger

Question 24

what is the quick way to write current directory in a pathname?

Answer 24

.

Question 25

what is the command for printing two files together?

Answer 25

cat

Question 26

what does > do?

Answer 26

replaces the following file with the content before the symbol

Question 27

what does '>>' do?

Answer 27

appends the content before the symbol to the file that follows

Question 28

command to copy a directory?

Answer 28

cp -r

Question 29

command to see how much disk space is free?

Answer 29

df

Question 30

command to remove a directory and everything in it?

Answer 30

rm -r

Question 31

command to list all processes?

Answer 31

ps aux

Question 32

meaning of |?

Answer 32

'pipes' the result of a previous command into another

Question 33

command to end a process?

Answer 33

kill

Question 34

what does -9 do to the kill command?

Answer 34

tells the process to die immediately and not 'tidy up'

Question 35

how do you exit a more command?

Answer 35

q

Question 36

what does it mean for a file to begin with a .

Answer 36

hidden file

Question 37

what does -r do to ls?

Answer 37

lists things recursively from a directory

Question 38

how would you create an empty text file from the terminal?

Answer 38

touch

Question 39

what does the command du do?

Answer 39

it shows the disk usage for the current directory and its subdirectories.

Question 40

how does -s change the result of du?

Answer 40

summary - shows disk usage of current directory without splitting it up for each subdirectory

Question 41

how does -s* affect the result of du?

Answer 41

shows summarised disk usage information for each subdirectory of the directory

Question 42

what does -alg do to ls?

Answer 42

a = show all l = long listing g = omit owner column

Question 43

what does grep do?

Answer 43

search for a particular string or pattern in a file

Question 44

what needs to be used with grep if we want to search for a string of several words?

Answer 44

" " quote marks otherwise the shell tries to interpret the space

Question 45

how would you redirect the errors of a command somewhere?

Answer 45

command > (where you want normal results) > (where you want errors)

Question 46

what would grep interpret "st." as?

Answer 46

st followed by any single character

Question 47

whta does \ do inside quotes for grep?

Answer 47

the next character is read literally rather than as a regular expression

Question 48

how do you get a \ to be read literally?

Answer 48

with another backslash \\

Question 49

what's the difference between ls -r and ls -R ?

Answer 49

ls -r lists recursively from the bottom up whereas ls -R lists more typically from top down