How to use converted variable inside shell script [duplicate]

Question

I have below shell script:

while [[ -z "$hosts" ]];do
read hosts?"some string"
done

I want to convert this string to uppercase:

echo $hosts | awk '{print toupper(0)}'

Can I use this converted variable on some way? something like this:

bighosts="echo $hosts | awk '{print toupper(0)}'"

echo $bighosts

I know its not working, can you please provide me some way to use converted variable inside the script instead of creating new text file?

Answer 1

Here are two ways to convert a variable to upper case, one using awk and the other using tr:

host=abcd

# using awk
bighost=$(echo $host | awk '{print toupper($0)}')
echo host=$host bighost=$bighost
host=abcd bighost=ABCD

# using tr
bighost2=$(echo $host | tr 'a-z' 'A-Z')
echo host=$host bighost2=$bighost2
host=abcd bighost2=ABCD