Trjtdtk

So practically for my assignment I need to break out of a true while loop when the user inputs a number that gives a modulus remainder of 0, ex: (25 % 5 = 0 break loop) Where in my attempt below have I gone wrong?

while true
do
 echo "Please input anything here: "
 read INPUT

 if [ `expr $INPUT % 5` -eq 0 ]; then
 echo "you entered wrong"
 else
 echo "you entered right"
 break
fi
done

Move the break from the else part to the if part:

#!/bin/bash

while true
do
 echo "Please input anything here: "
 read INPUT

 if [ `expr $INPUT % 5` -eq 0 ]; then
 echo "you entered wrong"
 break
 else
 echo "you entered right"
 fi
done

It works for me according to @steeldriver's tips,

• 
  

  make sure you use bash

  
  
  

  #!/bin/bash
  

  
  


• 
  

  use the bash syntax for arithmetic evaluation

  
  
  

  ((...))
  

  
  

Otherwise the shellscript can remain the same,

#!/bin/bash

while true
do
 echo "Please input anything here: "
 read INPUT

 if (( INPUT % 5 == 0 )) ; then
 echo "you entered right"
 break
 else
 echo "you entered wrong"
 fi
done

Edit: You have modified the question. This answer corresponds to a previous version of the question. (It is not clear to me, if you want to break the loop, when there is no remainder or when there is a remainder.)

Since this is bash script we're talking about, you may want to use read -p and arithmetic evaluation ((...))

$ while read -p "Enter number:" input ; do (( input%5 == 0 )) && echo "Wrong"; break; || echo "alright"; done
Enter number:11
alright
Enter number:7
alright
Enter number:10
Wrong

Portably, you might want to use [ aka test

$ [ $((25%5)) -eq 0 ] && echo "Zero"
Zero
$ [ $((26%5)) -eq 0 ] && echo "Zero"
$