bash - how to return values from a bash function — CodeJobler

What I wanted to do was to set a variable in bash from a function. Not as easy as I would have hoped.

Here is the choice I used from the article:

The other way to return a value is to write your function so that it accepts a variable name as part of its command line and then set that variable to the result of the function:

function myfunc()
{
    local  __resultvar=$1
    local  myresult='some value'
    eval $__resultvar="'$myresult'"
}

myfunc result
echo $result

It seems to work just fine. Here is the code that I used in my common.sh function, for the work script RWS-1891.sh:

get_choice () {
    # https://www.linuxjournal.com/content/return-values-bash-functions
    # sets the passed in variable to set later
    local __resultvar=$1

    choice_arg=$2
    if [ -z "$choice_arg" ]
    then
        choice_arg="HERE"
    else        
        check_if_ask_for_help $choice_arg
        check_if_invalid_choicd $choice_arg 
    fi

    # sets the value into the passed in variable
    eval $__resultvar="'$choice_arg'"
}

called like this:

#### https://linuxhint.com/bash_lowercase_uppercase_strings/
#### upper-case the passed in choice 
####  - have to use for bash 3.2.57
####  - can't use nice bash 4+ way - silly macOS
#
MY_CHOICE=`echo $1 | tr "[:lower:]" "[:upper:]"`
echo "choice:  $MY_CHOICE"

get_choice MY_CHOICE "$MY_CHOICE"

Works pretty well.