github.com/catcombo/envcfg (go): Package envcfg provides functions to load values to a structure fields from .env file and from OS environment variables.  Declare a structure and use tag `env` to define associated environment variable names for desired fields.  Create a new structure to provide default values.  Call envcfg.Load() to load values from environment variables.  Keep in mind that the values are first loaded from the .env file (if it exists) and then from the OS environment variables that can override the values loaded from the file.  The syntax of the .env file should follow these rules:  A limited number of field types are supported, but they should be enough for most cases. Nested structures are supported, just mark nested fields with `env` tag as usual (no special syntax for .env file required). To load .env file from a different location or with a different name use LoadFile().
Keywords: environment-variables|golang