github.com/u-root/u-root@v7.0.1-0.20200915234505-ad7babab0a8e+incompatible/pkg/uflag/flagfile.go (about)

     1  // Copyright 2020 the u-root Authors. All rights reserved
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package uflag supports u-root-custom flags as well as flag files.
     6  package uflag
     7  
     8  import (
     9  	"fmt"
    10  	"strconv"
    11  	"strings"
    12  )
    13  
    14  // ArgvToFile encodes argv program arguments such that they can be stored in a
    15  // file.
    16  func ArgvToFile(args []string) string {
    17  	// We separate flags in the flags file with new lines, so we
    18  	// have to escape new lines.
    19  	//
    20  	// Go already has a nifty Quote mechanism which will escape
    21  	// more than just new-line, which won't hurt anyway.
    22  	var quoted []string
    23  	for _, arg := range args {
    24  		quoted = append(quoted, strconv.Quote(arg))
    25  	}
    26  	return strings.Join(quoted, "\n")
    27  }
    28  
    29  // FileToArgv converts argvs stored in a file back to an array of strings.
    30  func FileToArgv(content string) []string {
    31  	quotedArgs := strings.Split(content, "\n")
    32  	var args []string
    33  	for _, arg := range quotedArgs {
    34  		if len(arg) > 0 {
    35  			s, err := strconv.Unquote(arg)
    36  			if err != nil {
    37  				panic(fmt.Sprintf("flags file encoded wrong, arg %q, error %v", arg, err))
    38  			}
    39  			args = append(args, s)
    40  		}
    41  	}
    42  	return args
    43  }