Homework & Coursework Questions

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!

1. The problem statement, all variables and given/known data:

accept the selling price (range 5¢ to $1.05) as a command line argument (cents only); reject prices out of range or not multiples of 5; return to the operating system with a usage message


2. Relevant commands, code, scripts, algorithms:

if statment
%

3. The attempts at a solution (include all code and scripts):
if [ $1 -ge 5 -a $1 -le 105 -a $(( $1 % 5 == 0 )) ]
then
echo The selling price has been set to $1
else
Invalid amount


4. Complete Name of School (University), City (State), Country, Name of Professor, and Course Number (Link to Course):
Ryerson University, Toronto, Canada, Ikhari, CCPS 393

Note: Without school/professor/course information, you will be banned if you post here! You must complete the entire template (not just parts of it).

Your fi is missing. You're also out an echo.

$(( )) isn't part of the [ ] syntax, it gets substituted, so what you're doing amounts to "-a 0" or "-a 1" which doesn't make sense. I'd put it outside the [ ].


You certainly made a good start on it though! Only minor fixes needed:

Code:

if [ $1 -ge 5 -a $1 -le 105 ] && $(( $1 % 5 == 0 ))
then
        echo The selling price has been set to $1
else
        echo Invalid amount
fi

Before doing that if statement at all you should check if $1 is blank if [ -z "$1" ] ; then echo "no first parameter" ; exit ; fi otherwise that $(( )) will be a syntax error when $1 is blank.

thank you

---------- Post updated at 01:37 AM ---------- Previous update was at 12:44 AM ----------

Wait, still not working.... it works if no parameter entered and when parameter for else entered but not if number between 5 and 105 entered

this is what i have'

Code:

#!/bin/bash

if [ -z "$1" ] 
then echo "no first parameter"

exit

elif [ $1 -ge 5 -a $1 -le 105 ] && $(( $1 % 5 == 0 ))

then
    echo The selling price of pop has been set to $1 cents as per your request
  
else
    echo Invalid amount. Price must be between 5 and 105 cents

fi

---------- Post updated at 02:25 AM ---------- Previous update was at 01:37 AM ----------

Ok got it....had to remove the $

Code:

elif [ $1 -ge 5 -a $1 -le 105 ] && $(( $1 % 5 == 0 ))

one more question. I want to skip the first echo statement the first time the loop gets entered

while [ $total_inserted -lt $selling_price ] #keep prompting for more funds until selling price achieved
do

echo "You have inserted a total of ${total_inserted} cents. Please insert $total_remaining more cents"
echo 'Please insert coins (NDQR)'
read coin_inserted

Otherwise the progam will tell user that he entered 0 cents, which is pointless. Any ideas???