Scripting

Question 1

What is the location for system binaries?

Answer 1

/usr/local/sbin

Question 2

Bash shbang

Answer 2

#!/bin/bash

Question 3

Check if user exist

Answer 3

getent passwd $user

Question 4

Execute a script on which you have no executable permission

Answer 4

sh script.sh

Question 5

Loop through servera to serverd, utility, bastion and get their uptime

Answer 5

for i in server{a..d} utility bastion; do 
       ssh $i uptime; 
 done

Question 6

Read input from keyboard into a variable animal

Answer 6

read -p "Then your animal: " animal

Question 7

Example case statemen

Answer 7

case $animal; in
 person)
       echo "This is a person"
  ;;
dog)
       echo "This is a dog"
;;
*)
       echo "Unknown anuimal"
        exit 1
;;
esac

Question 8

BRE

Answer 8

Basic Regular Expression

Question 9

ERE

Answer 9

Extended Regular Expression

Question 10

With grep show the line number where the pattern was found

Answer 10

grep -n root /etc/passwd

Question 11

With grep, count the number of lines where the pattern was found

Answer 11

grep -c root /etc/passwd

Question 12

Grep: match to the begining of the line

Answer 12

grep ^root /etc/passwd

Question 13

Grep: match to the end of the line

Answer 13

grep root$ file

Question 14

Grep to match non comment line

Answer 14

grep ^[^#] file.txt

Question 15

strip comment function

Answer 15

sc(){
   grep ^[^#]  $1
}

Question 16

grep case insensitive search

Answer 16

grep -i root /etc/passwd

Question 17

Explain:

grep -e user -e group file.txt

Answer 17

grep -E 'user|group' file.txt