cmd/go: add -json flag to go env

"go env" prints Go environment information as a shell script format by
default but it's difficult for some tools (e.g. editor packages) to
interpret it.

The -json flag prints the environment in JSON format which
can be easily interpreted by a lot of tools.

$ go env -json
{
        "CC": "gcc",
        "CGO_CFLAGS": "-g -O2",
        "CGO_CPPFLAGS": "",
        "CGO_CXXFLAGS": "-g -O2",
        "CGO_ENABLED": "1",
        "CGO_FFLAGS": "-g -O2",
        "CGO_LDFLAGS": "-g -O2",
        "CXX": "g++",
        "GCCGO": "gccgo",
        "GOARCH": "amd64",
        "GOBIN": "/home/haya14busa/go/bin",
        "GOEXE": "",
        "GOGCCFLAGS": "-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build498013955=/tmp/go-build -gno-record-gcc-switches",
        "GOHOSTARCH": "amd64",
        "GOHOSTOS": "linux",
        "GOOS": "linux",
        "GOPATH": "/home/haya14busa",
        "GORACE": "",
        "GOROOT": "/home/haya14busa/src/go.googlesource.com/go",
        "GOTOOLDIR": "/home/haya14busa/src/go.googlesource.com/go/pkg/tool/linux_amd64",
        "PKG_CONFIG": "pkg-config"
}

Also, it supports arguments with -json flag.

$ go env -json GOROOT GOPATH GOBIN
{
        "GOBIN": "/home/haya14busa/go/bin",
        "GOPATH": "/home/haya14busa",
        "GOROOT": "/home/haya14busa/src/go.googlesource.com/go"
}

Fixes #12567

Change-Id: I75db3780f14a8ab8c7fa58cc3c9cc488ef7b66a1
Reviewed-on: https://go-review.googlesource.com/38757
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/cmd/dist/deps.go b/src/cmd/dist/deps.go
index 8ac5d839c20b38bc9321dfb89d374cfe989c7ef7..a731fb766dab04f32388017f434b9443a14b72c0 100644 (file)
--- a/src/cmd/dist/deps.go
+++ b/src/cmd/dist/deps.go
@@ -6,12 +6,12 @@ var builddeps = map[string][]string{
        "bufio":                             {"bytes", "errors", "internal/race", "io", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sync", "sync/atomic", "unicode", "unicode/utf8"},
        "bytes":                             {"errors", "internal/race", "io", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sync", "sync/atomic", "unicode", "unicode/utf8"},
        "cmd/go/internal/base":              {"bufio", "bytes", "cmd/go/internal/cfg", "cmd/go/internal/str", "context", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
-       "cmd/go/internal/bug":               {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/envcmd", "cmd/go/internal/load", "cmd/go/internal/str", "cmd/go/internal/web", "cmd/go/internal/work", "compress/flate", "compress/zlib", "container/heap", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
+       "cmd/go/internal/bug":               {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/envcmd", "cmd/go/internal/load", "cmd/go/internal/str", "cmd/go/internal/web", "cmd/go/internal/work", "compress/flate", "compress/zlib", "container/heap", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding", "encoding/base64", "encoding/binary", "encoding/json", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/buildid":           {"bufio", "bytes", "cmd/go/internal/cfg", "compress/flate", "compress/zlib", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/cfg":               {"bufio", "bytes", "errors", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "net/url", "os", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/clean":             {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/load", "cmd/go/internal/str", "cmd/go/internal/work", "compress/flate", "compress/zlib", "container/heap", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/doc":               {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/cfg", "cmd/go/internal/str", "context", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
-       "cmd/go/internal/envcmd":            {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/load", "cmd/go/internal/str", "cmd/go/internal/work", "compress/flate", "compress/zlib", "container/heap", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
+       "cmd/go/internal/envcmd":            {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/load", "cmd/go/internal/str", "cmd/go/internal/work", "compress/flate", "compress/zlib", "container/heap", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding", "encoding/base64", "encoding/binary", "encoding/json", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/fix":               {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/load", "cmd/go/internal/str", "compress/flate", "compress/zlib", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/fmtcmd":            {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/load", "cmd/go/internal/str", "compress/flate", "compress/zlib", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
        "cmd/go/internal/generate":          {"bufio", "bytes", "cmd/go/internal/base", "cmd/go/internal/buildid", "cmd/go/internal/cfg", "cmd/go/internal/load", "cmd/go/internal/str", "cmd/go/internal/work", "compress/flate", "compress/zlib", "container/heap", "context", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding/binary", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "hash/adler32", "internal/poll", "internal/race", "internal/syscall/windows", "internal/syscall/windows/registry", "internal/syscall/windows/sysdll", "io", "io/ioutil", "log", "math", "math/bits", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},

diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index 2f19d6599203a81af6c4e58ff446d394fae83127..f1bc10b32dd4a91b3138a891221fd3f326d56dbc 100644 (file)
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -6,6 +6,7 @@
 package envcmd
 
 import (
+       "encoding/json"
        "fmt"
        "os"
        "runtime"
@@ -18,8 +19,7 @@ import (
 )
 
 var CmdEnv = &base.Command{
-       Run:       runEnv,
-       UsageLine: "env [var ...]",
+       UsageLine: "env [-json] [var ...]",
        Short:     "print Go environment information",
        Long: `
 Env prints Go environment information.
@@ -28,9 +28,18 @@ 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.
+
+The -json flag prints the environment in JSON format
+instead of as a shell script.
        `,
 }
 
+func init() {
+       CmdEnv.Run = runEnv // break init cycle
+}
+
+var envJson = CmdEnv.Flag.Bool("json", false, "")
+
 func MkEnv() []cfg.EnvVar {
        var b work.Builder
        b.Init()
@@ -107,12 +116,26 @@ func runEnv(cmd *base.Command, args []string) {
        env := cfg.CmdEnv
        env = append(env, ExtraEnvVars()...)
        if len(args) > 0 {
-               for _, name := range args {
-                       fmt.Printf("%s\n", findEnv(env, name))
+               if *envJson {
+                       var es []cfg.EnvVar
+                       for _, name := range args {
+                               e := cfg.EnvVar{Name: name, Value: findEnv(env, name)}
+                               es = append(es, e)
+                       }
+                       printEnvAsJSON(es)
+               } else {
+                       for _, name := range args {
+                               fmt.Printf("%s\n", findEnv(env, name))
+                       }
                }
                return
        }
 
+       if *envJson {
+               printEnvAsJSON(env)
+               return
+       }
+
        for _, e := range env {
                if e.Name != "TERM" {
                        switch runtime.GOOS {
@@ -138,3 +161,18 @@ func runEnv(cmd *base.Command, args []string) {
                }
        }
 }
+
+func printEnvAsJSON(env []cfg.EnvVar) {
+       m := make(map[string]string)
+       for _, e := range env {
+               if e.Name == "TERM" {
+                       continue
+               }
+               m[e.Name] = e.Value
+       }
+       enc := json.NewEncoder(os.Stdout)
+       enc.SetIndent("", "\t")
+       if err := enc.Encode(m); err != nil {
+               base.Fatalf("%s", err)
+       }
+}