github.com/system-transparency/u-root@v6.0.1-0.20190919065413-ed07a650de4c+incompatible/cmds/core/chmod/chmod.go (about)

     1  // Copyright 2016-2017 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  // Change modifier bits of a file.
     6  //
     7  // Synopsis:
     8  //     chmod MODE FILE...
     9  //
    10  // Desription:
    11  //     MODE is a three character octal value.
    12  package main
    13  
    14  import (
    15  	"flag"
    16  	"fmt"
    17  	"log"
    18  	"os"
    19  	"path/filepath"
    20  	"strconv"
    21  )
    22  
    23  var (
    24  	recursive bool
    25  	reference string
    26  )
    27  
    28  func init() {
    29  	flag.BoolVar(&recursive,
    30  		"R",
    31  		false,
    32  		"do changes recursively")
    33  
    34  	flag.BoolVar(&recursive,
    35  		"recursive",
    36  		false,
    37  		"do changes recursively")
    38  
    39  	flag.StringVar(&reference,
    40  		"reference",
    41  		"",
    42  		"use mode from reference file")
    43  }
    44  
    45  func main() {
    46  	flag.Parse()
    47  	if len(flag.Args()) < 1 {
    48  		fmt.Fprintf(os.Stderr, "Usage of %s: [mode] filepath\n", os.Args[0])
    49  		flag.PrintDefaults()
    50  		os.Exit(1)
    51  	}
    52  
    53  	if len(flag.Args()) < 2 && reference == "" {
    54  		fmt.Fprintf(os.Stderr, "Usage of %s: [mode] filepath\n", os.Args[0])
    55  		flag.PrintDefaults()
    56  		os.Exit(1)
    57  	}
    58  
    59  	var mode os.FileMode
    60  	var fileList []string
    61  
    62  	if reference != "" {
    63  		fi, err := os.Stat(reference)
    64  		if err != nil {
    65  			log.Fatalf("bad reference file: %v", err)
    66  
    67  		}
    68  		mode = fi.Mode()
    69  		fileList = flag.Args()
    70  	} else {
    71  		modeString := flag.Args()[0]
    72  		octval, err := strconv.ParseUint(modeString, 8, 32)
    73  		if err != nil {
    74  			log.Fatalf("Unable to decode mode %q. Please use an octal value: %v", modeString, err)
    75  		} else if octval > 0777 {
    76  			log.Fatalf("Invalid octal value %0o. Value should be less than or equal to 0777.", octval)
    77  		}
    78  		mode = os.FileMode(octval)
    79  		fileList = flag.Args()[1:]
    80  	}
    81  
    82  	var exitError bool
    83  	for _, name := range fileList {
    84  		if recursive {
    85  			err := filepath.Walk(name, func(path string,
    86  				info os.FileInfo,
    87  				err error) error {
    88  				return os.Chmod(path, mode)
    89  			})
    90  			if err != nil {
    91  				log.Printf("%v", err)
    92  				exitError = true
    93  			}
    94  		} else {
    95  			if err := os.Chmod(name, mode); err != nil {
    96  				log.Printf("%v", err)
    97  				exitError = true
    98  			}
    99  		}
   100  	}
   101  	if exitError {
   102  		os.Exit(1)
   103  	}
   104  }