blob: fcade9d84e228400547fe3d9532b42ad8b655d32 [file] [log] [blame]
// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package base
import "strings"
// EnvForDir returns a copy of the environment
// suitable for running in the given directory.
// The environment is the current process's environment
// but with an updated $PWD, so that an os.Getwd in the
// child will be faster.
func EnvForDir(dir string, base []string) []string {
// Internally we only use rooted paths, so dir is rooted.
// Even if dir is not rooted, no harm done.
return MergeEnvLists([]string{"PWD=" + dir}, base)
// MergeEnvLists merges the two environment lists such that
// variables with the same name in "in" replace those in "out".
// This always returns a newly allocated slice.
func MergeEnvLists(in, out []string) []string {
out = append([]string(nil), out...)
for _, inkv := range in {
k := strings.SplitAfterN(inkv, "=", 2)[0]
for i, outkv := range out {
if strings.HasPrefix(outkv, k) {
out[i] = inkv
continue NextVar
out = append(out, inkv)
return out