/* Copyright 2022 The Kubernetes Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package templates import ( "bytes" "fmt" "io" "strings" "github.com/mitchellh/go-wordwrap" flag "github.com/spf13/pflag" ) const offset = 10 // HelpFlagPrinter is a printer that // processes the help flag and print // it to i/o writer type HelpFlagPrinter struct { wrapLimit uint out io.Writer } // NewHelpFlagPrinter will initialize a HelpFlagPrinter given the // i/o writer func NewHelpFlagPrinter(out io.Writer, wrapLimit uint) *HelpFlagPrinter { return &HelpFlagPrinter{ wrapLimit: wrapLimit, out: out, } } // PrintHelpFlag will beautify the help flags and print it out to p.out func (p *HelpFlagPrinter) PrintHelpFlag(flag *flag.Flag) { formatBuf := new(bytes.Buffer) writeFlag(formatBuf, flag) wrappedStr := formatBuf.String() flagAndUsage := strings.Split(formatBuf.String(), "\n") flagStr := flagAndUsage[0] // if the flag usage is longer than one line, wrap it again if len(flagAndUsage) > 1 { nextLines := strings.Join(flagAndUsage[1:], " ") wrappedUsages := wordwrap.WrapString(nextLines, p.wrapLimit-offset) wrappedStr = flagStr + "\n" + wrappedUsages } appendTabStr := strings.ReplaceAll(wrappedStr, "\n", "\n\t") fmt.Fprintf(p.out, appendTabStr+"\n\n") } // writeFlag will output the help flag based // on the format provided by getFlagFormat to i/o writer func writeFlag(out io.Writer, f *flag.Flag) { deprecated := "" if f.Deprecated != "" { deprecated = fmt.Sprintf(" (DEPRECATED: %s)", f.Deprecated) } fmt.Fprintf(out, getFlagFormat(f), f.Shorthand, f.Name, f.DefValue, f.Usage, deprecated) }