Bash Scripting

Question 1

What do you put at the beginning of bash scripts?

Answer 1

!/bin/bash

Question 2

Where should you place a script if you want it to be executable from anywhere?

Answer 2

/home/user/bin

Question 3

What do you have to do to the script myscript before you can run it?

Answer 3

chmod u+x myscript

Question 4

myvar = $1

Answer 4

Will assign the value of the first argument to myvar

Question 5

$#

Answer 5

Refers to the total number of arguments

Question 6

How to do a numerical comparison with an if statement in a bash script

Answer 6

if (( $var == 0 ))

Question 7

What does an if block end with?

Answer 7

fi

Question 8

if test -f file

Answer 8

Tests if $file is a file

Question 9

if [ -f $file ]

Answer 9

Tests if $file is a file

Question 10

if [ -z “$string” ]

Answer 10

Checks if $string is empty

Question 11

if statement flag for greater than

Answer 11

-gt

Question 12

if statement flag for less than

Answer 12

-lt

Question 13

if statement flag for greater than or equal

Answer 13

-ge

Question 14

if statement flag for less than or equal

Answer 14

-le

Question 15

if statement flag for equal

Answer 15

-eq

Question 16

if statement flag for not equal

Answer 16

-ne

Question 17

if statement flag for testing if directory

Answer 17

-d

Question 18

if statement flag for testing if symlink

Answer 18

-l

Question 19

What does putting a command between ` ` do in a bash script?

Answer 19

Executes the command in a new shell then immediately closes the shell

Question 20

Which brackets must you use in order to use regular expressions and && and stuff?

Answer 20

[[ ]]

Question 21

if statement flag for &&

Answer 21

-a

Question 22

if statement flag for ||

Answer 22

-o

Question 23

for statement syntax

Answer 23

for a in b
do
blahblah
done

Question 24

while statement syntax

Answer 24

while [some condition];
do
blahblah;
done

Question 25

case statement syntax

Answer 25

case $var in
1) first
do this thing;;
2) second
do this other thing;;
*)
this is the default
esac

Question 26

read -n2 var

Answer 26

will read in 2 characters and put them in var

Question 27

read -t

Answer 27

If input is not given within a certain time frame the script will move on

Question 28

if [ -x $file ]

Answer 28

If $file exists and is executable

Question 29

seq 10

Answer 29

Will print 1 through 10 in sequential order

Question 30

seq 1 5 20

Answer 30

Will print 1-20 in increments of 5