env

func EnvironWithout ¶

func EnvironWithout(names ...string) []string

EnvironWithout returns the process environment without the named variables. Owned names remove both spellings; foreign names remove only themselves.

WHAT IT IS FOR: a child that is not part of some arrangement must not inherit the arrangement's NAMES. A descriptor handed to a child at least shows up in lsof; an inherited variable is invisible, and it travels to every grandchild for the life of the tree.

The worked case is the heavy-suite lock (cmd/codeaf-suite-lock's suiteEnviron). Exporting the lock's path so the wrapper could read it handed it to the SUITE as well, so every process the suite started tried to take a lock the suite itself was already holding, and refused itself. It made the package untestable from inside a locked box, which is a locking scheme nobody can gate.

func Get ¶

func Get(name string) string

Get reads a statically known codeaf variable with its legacy fallback.

func Legacy ¶

func Legacy(name string) string

Legacy returns the former spelling of an owned variable.

func Lookup ¶

func Lookup(name string) (string, bool)

Lookup is Get with the presence bit of the spelling that supplied the value.

func LookupValue ¶

func LookupValue(name string) (string, bool)

LookupValue is Value with os.LookupEnv's presence bit.

func Spelling ¶

func Spelling(name string) (string, bool)

Spelling names the spelling that supplied an owned variable's value: the current one when it is set and non-empty, the former one when only it is set. A receipt that says which variable answered has to say the one the person actually wrote, or it points them at a row they never set. When neither answers it is the current name, unset.

func Value ¶

func Value(name string) string

Value reads a runtime-supplied name. Foreign variables are read plainly.