const (
// DefaultListFormat constant to use to display usage in a list format
DefaultListFormat = `This application is configured via the environment. The following environment
variables can be used:
{{range .}}
{{usage_key .}}
[description] {{usage_description .}}
[type] {{usage_type .}}
[default] {{usage_default .}}
[required] {{usage_required .}}{{end}}
`
// DefaultTableFormat constant to use to display usage in a tabular format
DefaultTableFormat = `This application is configured via the environment. The following environment
variables can be used:
KEY TYPE DEFAULT REQUIRED DESCRIPTION
{{range .}}{{usage_key .}} {{usage_type .}} {{usage_default .}} {{usage_required .}} {{usage_description .}}
{{end}}`
)
ErrInvalidSpecification indicates that a specification is of the wrong type.
var ErrInvalidSpecification = errors.New("specification must be a struct pointer")
func CheckDisallowed(prefix string, spec interface{}) error
CheckDisallowed checks that no environment variables with the prefix are set that we don't know how or want to parse. This is likely only meaningful with a non-empty prefix.
func MustProcess(prefix string, spec interface{})
MustProcess is the same as Process but panics if an error occurs
func Process(prefix string, spec interface{}) error
Process populates the specified struct based on environment variables
func Usage(prefix string, spec interface{}) error
Usage writes usage information to stdout using the default header and table format
func Usagef(prefix string, spec interface{}, out io.Writer, format string) error
Usagef writes usage information to the specified io.Writer using the specifed template specification
func Usaget(prefix string, spec interface{}, out io.Writer, tmpl *template.Template) error
Usaget writes usage information to the specified io.Writer using the specified template
Decoder has the same semantics as Setter, but takes higher precedence. It is provided for historical compatibility.
type Decoder interface {
Decode(value string) error
}
A ParseError occurs when an environment variable cannot be converted to the type required by a struct field during assignment.
type ParseError struct {
KeyName string
FieldName string
TypeName string
Value string
Err error
}
func (e *ParseError) Error() string
Setter is implemented by types can self-deserialize values. Any type that implements flag.Value also implements Setter.
type Setter interface {
Set(value string) error
}