The variable expansion rules are different from the Bourne shell rules

[kmkaplan]

The rules are different in the shell and in dotenv. This is confusing. Is it possible to adopt the shell rules?

These rules apply to dotenv (from the README):

VAR=one
VAR_2=two
# Curly braces are useful in cases when we need to use a variable with non-alphanumeric name
RESULT=$VAR_2 #value: 'one_2' since $ with no curly braces stops after first non-alphanumeric symbol 
RESULT=${VAR_2} #value: 'two'

In Bourne shell the rules are different:

VAR=one
VAR_2=two
RESULT=$VAR_2 #value: 'two' since $ with no curly braces uses as much as possible
RESULT=${VAR_2} #value: 'two' same thing
RESULT=${VAR}_2 #value: 'one_2', the curly brace mark the end of the variable name

[Plecra]

For something more official, the POSIX specification defines it as "Parameter Expansion" in the same way as the Bourne shell examples.