Git Bash Commands - UNIX like (Wk 3 UCSD)

Question 1

What is the UNIX shell?

Answer 1

Interpreter between the user and the kernel?

Question 2

What is an abbreviation for a unique identifier that identifies a process running from the shell?

Answer 2

PID

Question 3

Refer to parent dir

Answer 3

../

Question 4

how do you refer the user’s home directory

Answer 4

~ or ~username/

Question 5

list files and folders in unix dir

Answer 5

ls (get help for all of the options)

Question 6

show contents of text files

Answer 6

cat filename

Question 7

get the documentation for a unix command

Answer 7

man commandName, eg man ls (git bash, this doesn’t work - need to use help commandName, and doesn’t have all)

Question 8

what is standard input

Answer 8

stdin - usually keyboard, but can read from file

Question 9

what is standard output

Answer 9

stdout - usually terminal, but can be switched to file

Question 10

what is standard error

Answer 10

stderr - usually terminal

Question 11

command to make a directory

Answer 11

mkdir dirName

Question 12

list hidden files

Answer 12

ls -a

Question 13

copy file fruits.txt from parent directory to current directory

Answer 13

cp ../fruits.txt .

.. is parent; . is current dir

Question 14

mv a file (eg, don’t copy)

Answer 14

mv path/file targetDir

Question 15

list all files with .txt extension in parent directory using wildcard

Answer 15

ls .. *.txt

Question 16

how to redirect standard input to a file

Answer 16

command < filenamein

Question 17

redirect standard output to a file

Answer 17

command > filenameout

Question 18

redirect standard error to a file

Answer 18

command 2> errorout

Question 19

redirect standard out and error in one command

Answer 19

command 2> errorout > fileout

Question 20

how do you append to a file instead of redirecting

Answer 20

command&raquo_space; fileout 2» fileerror

Question 21

send standard error and stdout to same file

Answer 21

command > afile 2>&1

Question 22

list out lines of text file screen by screen

Answer 22

less filename (q to exit reviewing line by line)

Question 23

sort lines in fruits.txt and write to fruits2.txt

Answer 23

sort fruits.txt > fruits2.txt (sorts alphabetically)

Question 24

get unique lines in a file and write to file2

Answer 24

uniq fruits.txt > file2

Question 25

count number of words in a file, or just lines

Answer 25

wc filename.txt, wc -l filename.txt (just lines)

Question 26

execute both pwd command and ls -l, with ls -l out to a file

Answer 26

pwd; ls -l > filelsout

Question 27

combine pwd command with ls -l, with both outputs to a file

Answer 27

(pwd; ls -l) > filebothout