environ

Documentation

Overview

Package environ is a simple environment variable manipulation library. It couples the system's environment, representated as a []string of KEY[=VALUE] strings, into a key/value map and back.

Index

• func Join(k, v string) string
• func Split(v string) (key, value string)
• func SystemIsCaseInsensitive() bool
• type Env
  • func New(s []string) Env
  • func System() Env
  • func (e Env) Clone() Env
  • func (e Env) Get(k string) (v string, ok bool)
  • func (e Env) GetEmpty(k string) string
  • func (e Env) Iter(cb func(k, v string) bool)
  • func (e Env) Len() int
  • func (e *Env) Load(m map[string]string)
  • func (e *Env) LoadSlice(s []string)
  • func (e Env) Map() map[string]string
  • func (e *Env) Remove(k string) bool
  • func (e *Env) RemoveMatch(fn func(k, v string) bool)
  • func (e *Env) Set(k, v string)
  • func (e *Env) SetEntry(entry string)
  • func (e Env) Sorted() []string
  • func (e Env) String() string
  • func (e *Env) Update(other Env)

Functions

func Join

func Join(k, v string) string

Join creates an environment variable definition for the supplied key/value.

func Split

func Split(v string) (key, value string)

Split splits the supplied environment variable value into a key/value pair.

If v is of the form:

• KEY, returns (KEY, "")
• KEY=, returns (KEY, "")
• KEY=VALUE, returns (KEY, VALUE)

func SystemIsCaseInsensitive

func SystemIsCaseInsensitive() bool

SystemIsCaseInsensitive returns true if the local operating system treats environment variable keys in a case-insensitive manner.

Types

type Env

type Env struct {
	// CaseInsensitive is true if environment keys are case-insensitive.
	CaseInsensitive bool
	// contains filtered or unexported fields
}

Env contains system environment variables. It preserves each environment variable verbatim (even if invalid).

func New

func New(s []string) Env

New instantiates a new Env instance from the supplied set of environment KEY=VALUE strings using LoadSlice.

The environment is automatically configured with the local system's case insensitivity.

func System

func System() Env

System returns an Env instance instantiated with the current os.Environ values.

The environment is automatically configured with the local system's case insensitivity.

func (Env) Clone

func (e Env) Clone() Env

Clone creates a new Env instance that is identical to, but independent from, e.

func (Env) Get

func (e Env) Get(k string) (v string, ok bool)

Get returns the environment value for the supplied key.

If the value is defined, ok will be true and v will be set to its value (note that this can be empty if the environment has an empty value). If the value is not defined, ok will be false.

func (Env) GetEmpty

func (e Env) GetEmpty(k string) string

GetEmpty is the same as Get, except that instead of returning a separate boolean indicating the presence of a key, it will return an empty string if the key is missing.

func (Env) Iter

func (e Env) Iter(cb func(k, v string) bool)

Iter iterates through all of the key/value pairs in Env and invokes the supplied callback, cb, for each element.

If the callback returns false, iteration will stop immediately.

func (Env) Len

func (e Env) Len() int

Len returns the number of environment variables defined in e.

func (*Env) Load

func (e *Env) Load(m map[string]string)

Load adds environment variables defined in a key/value map to an existing environment.

func (*Env) LoadSlice

func (e *Env) LoadSlice(s []string)

LoadSlice adds environment variable entries, specified as "KEY[=VALUE]" strings, into an existing environment.

Entries are added in order. If there are duplicates, later entries will override earlier ones.

func (Env) Map

func (e Env) Map() map[string]string

Map returns a map of the key/value values in the environment.

This is a clone of the contents of e; manipulating this map will not change the values in e.

func (*Env) Remove

func (e *Env) Remove(k string) bool

Remove removes a value from the environment, returning true if the value was present. If the value was missing, Remove returns false.

Remove is different from Set(k, "") in that Set persists the key with an empty value, while Remove removes it entirely.

func (*Env) RemoveMatch

func (e *Env) RemoveMatch(fn func(k, v string) bool)

RemoveMatch iterates over all keys and values in the environment, invoking the callback function, fn, for each key/value pair. If fn returns true, the key is removed from the environment.

func (*Env) Set

func (e *Env) Set(k, v string)

Set sets the supplied environment key and value.

func (*Env) SetEntry

func (e *Env) SetEntry(entry string)

SetEntry sets the supplied environment to a "KEY[=VALUE]" entry.

func (Env) Sorted

func (e Env) Sorted() []string

Sorted returns the contents of the environment, sorted by key.

func (Env) String

func (e Env) String() string

func (*Env) Update

func (e *Env) Update(other Env)

Update adds all key/value from other to the current environment. If there is a duplicate key, the value from other will overwrite the value from e.

Values from other will be sorted and added in alphabetic order. This means that if e is case insensitive and there are multiple keys in other that converge on the same case insensitive key, the one that is alphabetically highest will be added.