1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
// Copyright 2021 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 cmd
import (
"context"
"flag"
"fmt"
"text/tabwriter"
"golang.org/x/tools/internal/tool"
)
// subcommands is a helper that may be embedded for commands that delegate to
// subcommands.
type subcommands []tool.Application
func (s subcommands) DetailedHelp(f *flag.FlagSet) {
w := tabwriter.NewWriter(f.Output(), 0, 0, 2, ' ', 0)
defer w.Flush()
fmt.Fprint(w, "\nSubcommand:\n")
for _, c := range s {
fmt.Fprintf(w, " %s\t%s\n", c.Name(), c.ShortHelp())
}
printFlagDefaults(f)
}
func (s subcommands) Usage() string { return "<subcommand> [arg]..." }
func (s subcommands) Run(ctx context.Context, args ...string) error {
if len(args) == 0 {
return tool.CommandLineErrorf("must provide subcommand")
}
command, args := args[0], args[1:]
for _, c := range s {
if c.Name() == command {
s := flag.NewFlagSet(c.Name(), flag.ExitOnError)
return tool.Run(ctx, s, c, args)
}
}
return tool.CommandLineErrorf("unknown subcommand %v", command)
}
func (s subcommands) Commands() []tool.Application { return s }
// getSubcommands returns the subcommands of a given Application.
func getSubcommands(a tool.Application) []tool.Application {
// This interface is satisfied both by tool.Applications
// that embed subcommands, and by *cmd.Application.
type hasCommands interface {
Commands() []tool.Application
}
if sub, ok := a.(hasCommands); ok {
return sub.Commands()
}
return nil
}
|
