golang env 代码
文件路径：/src/cmd/go/internal/base/env.go
/ 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 (
"cmd/go/internal/cfg"
"fmt"
"os"
"path/filepath"
"runtime"
)
/ AppendPWD returns the result of appending PWD=dir to the environment base.
/
/ The resulting environment makes os.Getwd more efficient for a subprocess
/ running in dir, and also improves the accuracy of paths relative to dir
/ if one or more elements of dir is a symlink.
func AppendPWD(base []string, dir string) []string {
/ POSIX requires PWD to be absolute.
/ Internally we only use absolute paths, so dir should already be absolute.
if !filepath.IsAbs(dir) {
panic(fmt.Sprintf("AppendPWD with relative path %q", dir))
}
return append(base, "PWD="+dir)
}
/ AppendPATH returns the result of appending PATH=$GOROOT/bin:$PATH
/ (or the platform equivalent) to the environment base.
func AppendPATH(base []string) []string {
if cfg.GOROOTbin == "" {
return base
}
pathVar := "PATH"
if runtime.GOOS == "plan9" {
pathVar = "path"
}
path := os.Getenv(pathVar)
if path == "" {
return append(base, pathVar+"="+cfg.GOROOTbin)
}
return append(base, pathVar+"="+cfg.GOROOTbin+string(os.PathListSeparator)+path)
}