mirror of https://github.com/golang/go.git
60 lines
1.5 KiB
Go
60 lines
1.5 KiB
Go
// 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
|
|
}
|