idioms for returning multiple values in shell scripting

Question

Are there any idioms for returning multiple values from a bash function within a script?

http://tldp.org/LDP/abs/html/assortedtips.html describes how to echo multipl

Answer 1

This question was posted 5 years ago, but I have some interesting answer to post. I have just started learning bash, and I also encounter to the same problem as you did. I think this trick might be helpful:

#!/bin/sh

foo=""
bar=""

my_func(){
    echo 'foo="a"; bar="b"'
}

eval $(my_func)
echo $foo $bar
# result: a b

This trick is also useful for solving a problem when a child process can not send back a value to its parent process.

Answer 2

Yet another way:

function get_tuple()
{
  echo -e "Value1\nValue2"
}

IFS=$'\n' read -d '' -ra VALUES < <(get_tuple)
echo "${VALUES[0]}" # Value1
echo "${VALUES[1]}" # Value2

Answer 3

you can make use of associative arrays with you have bash 4 eg

declare -A ARR
function foo(){
  ...
  ARR["foo_return_value_1"]="VAR1"
  ARR["foo_return_value_2"]="VAR2"
}

you can combine them as strings.

function foo(){
  ...
  echo "$var1|$var2|$var3"
}

then whenever you need to use those return values,

ret="$(foo)"
IFS="|"
set -- $ret
echo "var1 one is: $1"
echo "var2 one is: $2"
echo "var3 one is: $3"

Answer 4

I am new to bash, But found this code helping.

function return_multiple_values() {
        eval "$1='What is your name'"
        eval "$2='my name is: BASH'"
    }
    
    return_var=''
    res2=''
    return_multiple_values return_var res2
    echo $return_var
    echo $res2