codekingpro/portable-devtools

1// Copyright 2022 The Go Authors. All rights reserved.2// Use of this source code is governed by a BSD-style3// license that can be found in the LICENSE file.4 5package main6 7import (8	"os/exec"9	"strings"10)11 12// setDir sets cmd.Dir to dir, and also adds PWD=dir to cmd's environment.13func setDir(cmd *exec.Cmd, dir string) {14	cmd.Dir = dir15	if cmd.Env != nil {16		// os/exec won't set PWD automatically.17		setEnv(cmd, "PWD", dir)18	}19}20 21// setEnv sets cmd.Env so that key = value.22func setEnv(cmd *exec.Cmd, key, value string) {23	cmd.Env = append(cmd.Environ(), key+"="+value)24}25 26// unsetEnv sets cmd.Env so that key is not present in the environment.27func unsetEnv(cmd *exec.Cmd, key string) {28	cmd.Env = cmd.Environ()29 30	prefix := key + "="31	newEnv := []string{}32	for _, entry := range cmd.Env {33		if strings.HasPrefix(entry, prefix) {34			continue35		}36		newEnv = append(newEnv, entry)37		// key may appear multiple times, so keep going.38	}39	cmd.Env = newEnv40}41