57 lines
1.1 KiB
Go
57 lines
1.1 KiB
Go
// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
|
|
// All rights reserved. Use of this source code is governed by an MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
import (
|
|
"bytes"
|
|
"flag"
|
|
"fmt"
|
|
"io"
|
|
"text/tabwriter"
|
|
)
|
|
|
|
func optionTable(w io.Writer, rows [][]string) {
|
|
tw := tabwriter.NewWriter(w, 2, 4, 2, ' ', 0)
|
|
for _, row := range rows {
|
|
for i, cell := range row {
|
|
if i > 0 {
|
|
tw.Write([]byte("\t"))
|
|
}
|
|
tw.Write([]byte(cell))
|
|
}
|
|
tw.Write([]byte("\n"))
|
|
}
|
|
tw.Flush()
|
|
}
|
|
|
|
func usageFor(fs *flag.FlagSet, usage string, extra string) func() {
|
|
return func() {
|
|
var b bytes.Buffer
|
|
b.WriteString("Usage:\n " + usage + "\n")
|
|
|
|
var options [][]string
|
|
fs.VisitAll(func(f *flag.Flag) {
|
|
var opt = " -" + f.Name
|
|
|
|
if f.DefValue != "false" {
|
|
opt += "=" + fmt.Sprintf("%q", f.DefValue)
|
|
}
|
|
|
|
options = append(options, []string{opt, f.Usage})
|
|
})
|
|
|
|
if len(options) > 0 {
|
|
b.WriteString("\nOptions:\n")
|
|
optionTable(&b, options)
|
|
}
|
|
|
|
fmt.Println(b.String())
|
|
|
|
if len(extra) > 0 {
|
|
fmt.Println(extra)
|
|
}
|
|
}
|
|
}
|