14_conditionals.sh (1267B)
1 #!/bin/sh 2 3 # As with other programming languages, we can evaluate if conditions or 4 # statements are true or false. In this exercise we will be dealing with 5 # strings and basic if/else structure. Below are 3 examples of this. 6 # 7 # $ option="yes" 8 # $ if [ "$option" = "yes" ]; then 9 # $ echo "option enabled" 10 # $ fi 11 # 12 # $ password="shellling123" 13 # $ if [ "$name" = "shellling123" ]; then 14 # $ echo "access granted" 15 # $ else 16 # $ echo "access denied" 17 # $ fi 18 # 19 # $ printf "Enter name: " 20 # $ read name 21 # $ if [ "$name" = "shellling" ]; then 22 # $ echo "Welcome!" 23 # $ elif [ "$name" = "shelllings" ]; then 24 # $ echo "Welcome all!" 25 # $ else 26 # $ echo "You are not welcome here." 27 # $ fi 28 # 29 # Notice that there is spaces between the square brackets and that, for 30 # strings, there are quotation marks around the variables. There are 31 # more options than just '=' 32 # 33 # = # strict string comparison of equals 34 # != # strict string comparison of does not equal 35 # -z # checks if string is empty 36 # -n # checks if string is not empty 37 # 38 # Fix the incomplete script below, leave all the echo lines unchanged 39 40 if # check if user input is or is not empty here 41 if [ "$1" = "password123" ] then 42 echo "Welcome" 43 else 44 echo "Access not granted" 45 else 46 echo "Password not entered"