Add support for fallback if env variable is missing

[lesichkovm]

Would be nice if there was option for fallback option if a variable is missing

Something similar to:

func env(key, fallback string) string {
value, exists := os.LookupEnv(key)
if !exists {
value = fallback
}
return value
}

[D-sense]

@lesichkovm, I think there is a similar logic provided already. When you call the Load(filenames ...string) or Overload(filenames ...string), it first calls on filenamesOrDefault(filenames); If "filenames" is empty, a fallback is provided. This fallback expects to find ".env" file in the root folder.

[lesichkovm]

@D-sense it is not about loading files, but a helper function to check if an environmental variable exists:

myVar := Env("MYENV", "DEFAULT_IF_NOT_SET")

[D-sense]

@lesichkovm , please ignore the tagging of the PR. It was a mistake (I didn’t mean to tag it here).

On the point you raised, except I still haven’t gotten your point well enough, I think the existing logic already caters for that need (as outlined in my earlier response). I might be wrong though.

[nerg4l]

If I understand @lesichkovm correctly he would like to have a function which simplifies the following:

val, ok := os.LookupEnv("KEY")
if !ok {
  val = "DEFAULT_VAL"
}

Instead of the above code you could write this:

val := godotenv.Env("KEY", "DEFAULT_VAL")