docs: update

README.md

@@ -334,6 +334,8 @@ Hello, World
 
 ## Parsing a `key=val` file.
 
+This could be used to parse a simple `key=value` configuration file.
+
 ```shell
 # Setting 'IFS' tells 'read' where to split the string.
 while IFS='=' read -r key val; do
@@ -344,6 +346,18 @@ while IFS='=' read -r key val; do
     # '$key' stores the key.
     # '$val' stores the value.
     printf '%s: %s\n' "$key" "$val"
+
+    # Alternatively replacing 'printf' with the following
+    # populates variables called '$key' with the value of '$val'.
+    #
+    # NOTE: I would extend this with a check to ensure 'key' is
+    #       a valid variable name.
+    # export "$key=$val"
+    #
+    # Example with error handling:
+    #
+    # export "$key=$val" 2>/dev/null ||
+    #     printf 'warning %s is not a valid variable name\n' "$key"
 done < "file"
 ```