github.com/xyproto/u-root@v6.0.1-0.20200302025726-5528e0c77a3c+incompatible/cmds/core/mktemp/mktemp.go (about)

     1  // Copyright 2012-2018 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  // Mktemp makes a temporary file (or directory)
     6  //
     7  // Synopsis:
     8  //       mktemp [OPTION]... [TEMPLATE]
     9  //
    10  //       Create  a  temporary  file or directory, safely, and print its name.  TEMPLATE must contain at least 3 consecutive 'X's in last component.  If TEMPLATE is not specified, use tmp.XXXXXXXXXX, and --tmpdir is implied.  Files are
    11  //       created u+rw, and directories u+rwx, minus umask restrictions.
    12  //
    13  //       -d, --directory
    14  //              create a directory, not a file
    15  //
    16  //       -u, --dry-run
    17  //              do not create anything; merely print a name (unsafe)
    18  //
    19  //       -q, --quiet
    20  //              suppress diagnostics about file/dir-creation failure
    21  //
    22  //       --suffix=SUFF
    23  //              append SUFF to TEMPLATE; SUFF must not contain a slash.  This option is implied if TEMPLATE does not end in X
    24  //
    25  //       -p DIR, --tmpdir[=DIR]
    26  //              interpret TEMPLATE relative to DIR; if DIR is not specified, use $TMPDIR if set, else /tmp.  With this option, TEMPLATE must not be an absolute name; unlike with -t, TEMPLATE may contain  slashes,  but  mktemp  creates
    27  //              only the final component
    28  package main
    29  
    30  import (
    31  	"fmt"
    32  	"io/ioutil"
    33  	"log"
    34  	"os"
    35  	"strings"
    36  
    37  	flag "github.com/spf13/pflag"
    38  )
    39  
    40  type mktempflags struct {
    41  	d      bool
    42  	u      bool
    43  	q      bool
    44  	v      bool
    45  	prefix string
    46  	suffix string
    47  	dir    string
    48  }
    49  
    50  var (
    51  	flags mktempflags
    52  )
    53  
    54  func init() {
    55  	flag.BoolVarP(&flags.d, "directory", "d", false, "Make a directory")
    56  	flag.BoolVarP(&flags.u, "dry-run", "u", false, "Do everything save the actual create")
    57  	flag.BoolVarP(&flags.v, "quiet", "q", false, "Quiet: show no errors")
    58  	flag.StringVarP(&flags.prefix, "prefix", "s", "", "add a prefix -- the s flag is for compatibility with GNU mktemp")
    59  	flag.StringVarP(&flags.suffix, "suffix", "", "", "add a suffix to the prefix (rather than the end of the mktemp file)")
    60  	flag.StringVarP(&flags.dir, "tmpdir", "p", "", "Tmp directory to use. If this is not set, TMPDIR is used, else /tmp")
    61  }
    62  
    63  func usage() {
    64  	log.Fatalf("Usage: mktemp [options] [template]\n%v", flag.CommandLine.FlagUsages())
    65  }
    66  
    67  func mktemp() (string, error) {
    68  	if flags.dir == "" {
    69  		flags.dir = os.Getenv("TMPDIR")
    70  	}
    71  
    72  	if flags.u {
    73  		if !flags.q {
    74  			log.Printf("Not doing anything but dry-run is an inherently unsafe concept")
    75  		}
    76  		return "", nil
    77  	}
    78  
    79  	if flags.d {
    80  		d, err := ioutil.TempDir(flags.dir, flags.prefix)
    81  		return d, err
    82  	}
    83  	f, err := ioutil.TempFile(flags.dir, flags.prefix)
    84  	return f.Name(), err
    85  }
    86  
    87  func main() {
    88  	flag.Parse()
    89  
    90  	args := flag.Args()
    91  
    92  	switch len(args) {
    93  	case 1:
    94  		// To make this work, we strip the trailing X's, since the Go runtime doesn't work
    95  		// as old school mktemp(3) does. Just split on the first X.
    96  		// If they also specified a suffix, well, add that to the prefix I guess.
    97  		flags.prefix = flags.prefix + strings.Split(args[0], "X")[0] + flags.suffix
    98  	case 0:
    99  	default:
   100  		usage()
   101  	}
   102  
   103  	fileName, err := mktemp()
   104  	if err != nil && !flags.q {
   105  		log.Fatalf("%v", err)
   106  	}
   107  	fmt.Println(fileName)
   108  }