github.com/oweisse/u-root@v0.0.0-20181109060735-d005ad25fef1/cmds/elvish/eval/vars/env.go (about)

     1  package vars
     2  
     3  import (
     4  	"errors"
     5  	"os"
     6  )
     7  
     8  var errEnvMustBeString = errors.New("environment variable can only be set string values")
     9  
    10  // envVariable represents an environment variable.
    11  type envVariable struct {
    12  	name string
    13  }
    14  
    15  func (ev envVariable) Set(val interface{}) error {
    16  	if s, ok := val.(string); ok {
    17  		os.Setenv(ev.name, string(s))
    18  		return nil
    19  	}
    20  	return errEnvMustBeString
    21  }
    22  
    23  func (ev envVariable) Get() interface{} {
    24  	return string(os.Getenv(ev.name))
    25  }
    26  
    27  // NewEnv returns an environment variable.
    28  func NewEnv(name string) Var {
    29  	return envVariable{name}
    30  }