Question

1. Name the script thirsty.sh.
2. Ask the user if they are thirsty.
3. Read the user's response.
4. If they answer no or No, print an appropriate message and exit.
5. If they answer yes or Yes, ask what they would like to drink. Read the user's response.
   • If they answer water print "Clear crisp and refreshing."
   • If they answer beer print "Let me see some id."
   • If they answer wine print "one box or two."
   • If they answer anything else print "Coming right up."

Beginner's Linux.....for loops, while loops....if/elif/el...commands...simple but clean....please help with comments so I can understand

Answer 1

I have executed this in Linux Ubuntu.

To execute this script, I saved it as thirsty.sh. Then we make this executable with the command: chmod +x thirsty.sh

To run this, we use : ./thirsty.sh

Since you wanted a basic script, I executed this using only if, elif and else

If, else, elif statement syntax:

if [ expression 1 ]
then
   Statement(s) to be executed if expression 1 is true
elif [ expression 2 ]
then
   Statement(s) to be executed if expression 2 is true
elif [ expression 3 ]
then
   Statement(s) to be executed if expression 3 is true
else
   Statement(s) to be executed if no expression is true
fi

The if...elif...fi statement is the one level advance form of control statement that allows Shell to make correct decision out of several conditions.

#!/bin/sh

n2="No" # storing value of No in n2
n3="no" # storing value of no in n3
n4="Yes" # storing value of Yes in n4
n5="yes" # storing value of yes in n5
water="water" # # storing value of water in water
beer="beer" # storing value of beer in beer
wine="wine" # storing value of wine in wwine
something=" " # if user enter something else, it checks here
echo "Are you thirsty" # echo to print statement
read n1 #reading the user response and storing in n1


if [ "$n1" = "$n2" ] || [ "$n1" = "$n3" ] # if statement to compare two values
then # we use || (pipe) also know as OR which is used to compare two values
   echo "You're not thirsty. We'll exit now"


elif [ "$n1" = "$n4" ] || [ "$n1" = "$n5" ] # elif statement to compare two values
then
   read -p "What would you like to drink: " d1 #storing in d1

 

if [ "$d1" = "$water" ] #  comparing d1 with water
then
    echo "Clear crisp and refreshing" # if true, this is printed
elif [ "$d1" = "$beer" ] # comparing d1 with beer
then
    echo "Let me see some id" #if true, this is printed

elif [ "$d1" = "$wine" ] comparing d1 with wine
then
    echo "one box or two"
else # if nothing is true, else is executed
    
    echo "Coming right up." # executes when if is not executed
    break # breaks the statement and the script closes

fi # closing if statement with fi
fi # closing if statement with fi

Output:

All the given conditions were verified

If you have any doubts, leave a comment below before rating. I'll be happy to assist you further.

Do UPVOTE this as I have put a lot of EFFORT in answering this question. It really helps me.