#!/bin/sh
# If you only have a bash 4.x, you can test with compat 3.1 bash
# shopt -s compat31
FOO="var_with_two_words='foo bar' other_var='baz'"
# An "env variable" definer that use the read command to parse and define the env  variable
define() {
  IFS=\= read -r key value <<EOF
$1
EOF
 
  # Unquotting the value, adapt as it fit your needs
  value="${value#\'}"
  value="${value%\'}"
  read "${key}" << EOF
${value}
EOF
 
}
# Using the set command to "parse" the variables string
set ${FOO}
while [ "$1" ] ; do
  define "$1"
  shift
done
echo "var_with_two_words=${var_with_two_words}"
echo "other_var=${other_var}"
 

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