github.com/dannin/go@v0.0.0-20161031215817-d35dfd405eaa/src/cmd/go/env.go (about) 1 // Copyright 2012 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package main 6 7 import ( 8 "fmt" 9 "os" 10 "runtime" 11 "strings" 12 ) 13 14 var cmdEnv = &Command{ 15 Run: runEnv, 16 UsageLine: "env [var ...]", 17 Short: "print Go environment information", 18 Long: ` 19 Env prints Go environment information. 20 21 By default env prints information as a shell script 22 (on Windows, a batch file). If one or more variable 23 names is given as arguments, env prints the value of 24 each named variable on its own line. 25 `, 26 } 27 28 type envVar struct { 29 name, value string 30 } 31 32 func mkEnv() []envVar { 33 var b builder 34 b.init() 35 36 env := []envVar{ 37 {"GOARCH", goarch}, 38 {"GOBIN", gobin}, 39 {"GOEXE", exeSuffix}, 40 {"GOHOSTARCH", runtime.GOARCH}, 41 {"GOHOSTOS", runtime.GOOS}, 42 {"GOOS", goos}, 43 {"GOPATH", os.Getenv("GOPATH")}, 44 {"GORACE", os.Getenv("GORACE")}, 45 {"GOROOT", goroot}, 46 {"GOTOOLDIR", toolDir}, 47 48 // disable escape codes in clang errors 49 {"TERM", "dumb"}, 50 } 51 52 if gccgoBin != "" { 53 env = append(env, envVar{"GCCGO", gccgoBin}) 54 } else { 55 env = append(env, envVar{"GCCGO", gccgoName}) 56 } 57 58 switch goarch { 59 case "arm": 60 env = append(env, envVar{"GOARM", os.Getenv("GOARM")}) 61 case "386": 62 env = append(env, envVar{"GO386", os.Getenv("GO386")}) 63 } 64 65 if goos != "plan9" { 66 cmd := b.gccCmd(".") 67 env = append(env, envVar{"CC", cmd[0]}) 68 env = append(env, envVar{"GOGCCFLAGS", strings.Join(cmd[3:], " ")}) 69 cmd = b.gxxCmd(".") 70 env = append(env, envVar{"CXX", cmd[0]}) 71 } 72 73 if buildContext.CgoEnabled { 74 env = append(env, envVar{"CGO_ENABLED", "1"}) 75 } else { 76 env = append(env, envVar{"CGO_ENABLED", "0"}) 77 } 78 79 return env 80 } 81 82 func findEnv(env []envVar, name string) string { 83 for _, e := range env { 84 if e.name == name { 85 return e.value 86 } 87 } 88 return "" 89 } 90 91 // extraEnvVars returns environment variables that should not leak into child processes. 92 func extraEnvVars() []envVar { 93 var b builder 94 b.init() 95 cppflags, cflags, cxxflags, fflags, ldflags := b.cflags(&Package{}) 96 return []envVar{ 97 {"PKG_CONFIG", b.pkgconfigCmd()}, 98 {"CGO_CFLAGS", strings.Join(cflags, " ")}, 99 {"CGO_CPPFLAGS", strings.Join(cppflags, " ")}, 100 {"CGO_CXXFLAGS", strings.Join(cxxflags, " ")}, 101 {"CGO_FFLAGS", strings.Join(fflags, " ")}, 102 {"CGO_LDFLAGS", strings.Join(ldflags, " ")}, 103 } 104 } 105 106 func runEnv(cmd *Command, args []string) { 107 env := mkEnv() 108 env = append(env, extraEnvVars()...) 109 if len(args) > 0 { 110 for _, name := range args { 111 fmt.Printf("%s\n", findEnv(env, name)) 112 } 113 return 114 } 115 116 for _, e := range env { 117 if e.name != "TERM" { 118 switch runtime.GOOS { 119 default: 120 fmt.Printf("%s=\"%s\"\n", e.name, e.value) 121 case "plan9": 122 if strings.IndexByte(e.value, '\x00') < 0 { 123 fmt.Printf("%s='%s'\n", e.name, strings.Replace(e.value, "'", "''", -1)) 124 } else { 125 v := strings.Split(e.value, "\x00") 126 fmt.Printf("%s=(", e.name) 127 for x, s := range v { 128 if x > 0 { 129 fmt.Printf(" ") 130 } 131 fmt.Printf("%s", s) 132 } 133 fmt.Printf(")\n") 134 } 135 case "windows": 136 fmt.Printf("set %s=%s\n", e.name, e.value) 137 } 138 } 139 } 140 }