1 files changed, 89 insertions, 0 deletions
diff --git a/src/cmd/go/env.go b/src/cmd/go/env.go
new file mode 100644
index 000000000..d5b034809
--- /dev/null
+++ b/src/cmd/go/env.go
@@ -0,0 +1,89 @@
+// Copyright 2012 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 main
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+)
+
+var cmdEnv = &Command{
+	Run:       runEnv,
+	UsageLine: "env [var ...]",
+	Short:     "print Go environment information",
+	Long: `
+Env prints Go environment information.
+
+By default env prints information as a shell script
+(on Windows, a batch file).  If one or more variable
+names is given as arguments,  env prints the value of
+each named variable on its own line.
+	`,
+}
+
+type envVar struct {
+	name, value string
+}
+
+func mkEnv() []envVar {
+	var b builder
+	b.init()
+
+	env := []envVar{
+		{"GOROOT", goroot},
+		{"GOBIN", gobin},
+		{"GOARCH", goarch},
+		{"GOCHAR", archChar},
+		{"GOOS", goos},
+		{"GOEXE", exeSuffix},
+		{"GOHOSTARCH", runtime.GOARCH},
+		{"GOHOSTOS", runtime.GOOS},
+		{"GOTOOLDIR", toolDir},
+		{"GOGCCFLAGS", strings.Join(b.gccCmd(".")[3:], " ")},
+	}
+
+	if buildContext.CgoEnabled {
+		env = append(env, envVar{"CGO_ENABLED", "1"})
+	} else {
+		env = append(env, envVar{"CGO_ENABLED", "0"})
+	}
+
+	return env
+}
+
+func findEnv(env []envVar, name string) string {
+	for _, e := range env {
+		if e.name == name {
+			return e.value
+		}
+	}
+	return ""
+}
+
+func runEnv(cmd *Command, args []string) {
+	env := mkEnv()
+	if len(args) > 0 {
+		for _, name := range args {
+			fmt.Printf("%s\n", findEnv(env, name))
+		}
+		return
+	}
+
+	switch runtime.GOOS {
+	default:
+		for _, e := range env {
+			fmt.Printf("%s=\"%s\"\n", e.name, e.value)
+		}
+	case "plan9":
+		for _, e := range env {
+			fmt.Printf("%s='%s'\n", e.name, strings.Replace(e.value, "'", "''", -1))
+		}
+	case "windows":
+		for _, e := range env {
+			fmt.Printf("set %s=%s\n", e.name, e.value)
+		}
+	}
+}