CanGetenv reports whether key is a valid go/env configuration key.

EnvFile returns the name of the Go environment configuration file.

EnvOr returns Getenv(key) if set, or else def.

Getenv gets the value for the configuration key.

-x flag.

CmdEnv is the new environment for running go tool commands.

Variables to be set by the main package.

Variables to be set by the main package.

OrigEnv is the original environment of the program at startup.

An EnvVar is an environment variable Name=Value, and an optional pointer to a corresponding variable.