eget

A tiny helper to access scoped environment variables.

eget uses a format string to dynamically construct calls to environment variables based on other environment variables. The most common use case for this is a situation where you may have environment variables prefixed or suffixed with environment names, i.e. VAR_STAGING and VAR_PRODUCTION and you want to dynamically select between them.

Doing this in bash is possible but somewhat cumbersome. With eget, you can define the format of your environment variables once and then easily reuse it across calls.

Usage

eget <variable_name>

Example

some-command -e VAR=$(eget VAR)

Customization

The default format string is {var_name}_{$ENV_NAME}. This means that the above call will result in the environment variable VAR_STAGING being called, if $ENV_NAME=staging.

The format string can be changed by setting the environment variable EGET_FMT. It follows a simplified version of the Python string formatting syntax, with the following rules:

1. The variable {var_name} is special and will be the name of the environment variable passed to eget.
2. Variables beginning with $ such as {$ENV_NAME} will be interpeted as environment variables and substituted with their values accordingly.
3. Format specifiers are supported, but currently only two are available: u (uppercase) and l (lowercase). u is the default, meaning all variable names will be uppercased by default. Format specifiers can be supplied like this: {$ENV_NAME:u} or {$ENV_NAME:l}