Question

I am trying to create a bash script that is essentially like a magic 8 ball with 6 different responses (Yes, No, Maybe, Hard to tell, Unlikely, and Unknown). The key is that once a response is given, it should not be given again until all responses have been given.

Here is what I have so far:

#!/bin/bash
echo "Ask and you shall receive your fortune: "
n=$((RANDOM*6/32767))
while [`grep $n temp | wc awk '{print$3}'` -eq 0]; do
   n=$((RANDOM*6/32767))
done
grep -v $n temp > temp2
mv temp2 temp

Basically I have the 6 responses all on different lines in the temp file, and I am trying to construct the loops so that once a response is given, it creates a new file without that response (temp2), then copies it back to temp. Then once the temp file is empty it will continue from the beginning.

I’m quite positive that my current inner loop is wrong, and that I need an outer loop, but I’m fairly new to this and I am stuck.

Any help will be greatly appreciated.

Answer 1

Try something like this:

#!/bin/bash

shuffle() {
   local i tmp size max rand

   # $RANDOM % (i+1) is biased because of the limited range of $RANDOM
   # Compensate by using a range which is a multiple of the array size.
   size=${#array[*]}
   max=$(( 32768 / size * size ))

   for ((i=size-1; i>0; i--)); do
      while (( (rand=$RANDOM) >= max )); do :; done
      rand=$(( rand % (i+1) ))
      tmp=${array[i]} array[i]=${array[rand]} array[rand]=$tmp
   done
}

array=( 'Yes' 'No' 'Maybe' 'Hard to tell' 'Unknown' 'Unlikely' )

shuffle
for var in "${array[@]}"
do
  echo -n "Ask a question: "
  read q
  echo "${var}"
done