/* Like env_get, but prints an error if envvar isn't defined in the environment. It always returns what env_get does, so it can be used in place of env_get without changing error handling otherwise.  */
char* from_env(const char *envvar)
/* Like env_get, but prints an error if envvar isn't defined in the environment. It always returns what env_get does, so it can be used in place of env_get without changing error handling otherwise.  */
char* from_env(const char *envvar)
{
	char *ret;
	ret = env_get(envvar);
	if (!ret)
		printf("missing environment variable: %s\n", envvar);
	return ret;
}