src/mktemp.c

   1 /* Create a temporary file or directory, safely.
   2    Copyright (C) 2007-2009 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Jim Meyering.  */
  18
  19 #include <config.h>
  20 #include <stdio.h>
  21 #include <sys/types.h>
  22 #include <getopt.h>
  23
  24 #include "system.h"
  25
  26 #include "error.h"
  27 #include "filenamecat.h"
  28 #include "quote.h"
  29 #include "tempname.h"
  30
  31 /* The official name of this program (e.g., no `g' prefix).  */
  32 #define PROGRAM_NAME "mktemp"
  33
  34 #define AUTHORS proper_name ("Jim Meyering")
  35
  36 static const char *default_template = "tmp.XXXXXXXXXX";
  37
  38 /* For long options that have no equivalent short option, use a
  39    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  40 enum
  41 {
  42   TMPDIR_OPTION = CHAR_MAX + 1
  43 };
  44
  45 static struct option const longopts[] =
  46 {
  47   {"directory", no_argument, NULL, 'd'},
  48   {"quiet", no_argument, NULL, 'q'},
  49   {"dry-run", no_argument, NULL, 'u'},
  50   {"tmpdir", optional_argument, NULL, TMPDIR_OPTION},
  51   {GETOPT_HELP_OPTION_DECL},
  52   {GETOPT_VERSION_OPTION_DECL},
  53   {NULL, 0, NULL, 0}
  54 };
  55
  56 void
  57 usage (int status)
  58 {
  59   if (status != EXIT_SUCCESS)
  60     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  61              program_name);
  62   else
  63     {
  64       printf (_("Usage: %s [OPTION]... [TEMPLATE]\n"), program_name);
  65       fputs (_("\
  66 Create a temporary file or directory, safely, and print its name.\n\
  67 If TEMPLATE is not specified, use tmp.XXXXXXXXXX.\n\
  68 "), stdout);
  69       fputs ("\n", stdout);
  70       fputs (_("\
  71   -d, --directory  create a directory, not a file\n\
  72 "), stdout);
  73       fputs (_("\
  74   -q, --quiet      suppress diagnostics about file/dir-creation failure\n\
  75 "), stdout);
  76       fputs (_("\
  77   -u, --dry-run    do not create anything; merely print a name (unsafe)\n\
  78 "), stdout);
  79       fputs (_("\
  80   --tmpdir[=DIR]   interpret TEMPLATE relative to DIR.  If DIR is\n\
  81                      not specified, use $TMPDIR if set, else /tmp.\n\
  82                      With this option, TEMPLATE must not be an absolute name.\n\
  83                      Unlike with -t, TEMPLATE may contain slashes, but even\n\
  84                      here, mktemp still creates only the final component.\n\
  85 "), stdout);
  86       fputs ("\n", stdout);
  87       fputs (_("\
  88   -p DIR           use DIR as a prefix; implies -t [deprecated]\n\
  89 "), stdout);
  90       fputs (_("\
  91   -t               interpret TEMPLATE as a single file name component,\n\
  92                      relative to a directory: $TMPDIR, if set; else the\n\
  93                      directory specified via -p; else /tmp [deprecated]\n\
  94 "), stdout);
  95       fputs ("\n", stdout);
  96       fputs (HELP_OPTION_DESCRIPTION, stdout);
  97       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  98       emit_bug_reporting_address ();
  99     }
 100
 101   exit (status);
 102 }
 103
 104 static size_t
 105 count_trailing_X_s (const char *s)
 106 {
 107   size_t len = strlen (s);
 108   size_t n = 0;
 109   for ( ; len && s[len-1] == 'X'; len--)
 110     ++n;
 111   return n;
 112 }
 113
 114 static int
 115 mkstemp_len (char *tmpl, size_t suff_len, bool dry_run)
 116 {
 117   return gen_tempname_len (tmpl, dry_run ? GT_NOCREATE : GT_FILE, suff_len);
 118 }
 119
 120 static int
 121 mkdtemp_len (char *tmpl, size_t suff_len, bool dry_run)
 122 {
 123   return gen_tempname_len (tmpl, dry_run ? GT_NOCREATE : GT_DIR, suff_len);
 124 }
 125
 126 int
 127 main (int argc, char **argv)
 128 {
 129   char const *dest_dir;
 130   char const *dest_dir_arg = NULL;
 131   bool suppress_stderr = false;
 132   int c;
 133   unsigned int n_args;
 134   char *template;
 135   bool use_dest_dir = false;
 136   bool deprecated_t_option = false;
 137   bool create_directory = false;
 138   bool dry_run = false;
 139   int status = EXIT_SUCCESS;
 140   size_t x_count;
 141   char *dest_name;
 142
 143   initialize_main (&argc, &argv);
 144   set_program_name (argv[0]);
 145   setlocale (LC_ALL, "");
 146   bindtextdomain (PACKAGE, LOCALEDIR);
 147   textdomain (PACKAGE);
 148
 149   atexit (close_stdout);
 150
 151   while ((c = getopt_long (argc, argv, "dp:qtuV", longopts, NULL)) != -1)
 152     {
 153       switch (c)
 154         {
 155         case 'd':
 156           create_directory = true;
 157           break;
 158         case 'p':
 159           dest_dir_arg = optarg;
 160           use_dest_dir = true;
 161           break;
 162         case 'q':
 163           suppress_stderr = true;
 164           break;
 165         case 't':
 166           use_dest_dir = true;
 167           deprecated_t_option = true;
 168           break;
 169         case 'u':
 170           dry_run = true;
 171           break;
 172
 173         case TMPDIR_OPTION:
 174           use_dest_dir = true;
 175           dest_dir_arg = optarg;
 176           break;
 177
 178         case_GETOPT_HELP_CHAR;
 179
 180         case 'V':
 181         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 182         default:
 183           usage (EXIT_FAILURE);
 184         }
 185     }
 186
 187   if (suppress_stderr)
 188     {
 189       /* From here on, redirect stderr to /dev/null.
 190          A diagnostic from getopt_long, above, would still go to stderr.  */
 191       if (!freopen ("/dev/null", "wb", stderr))
 192         error (EXIT_FAILURE, errno,
 193                _("failed to redirect stderr to /dev/null"));
 194     }
 195
 196   n_args = argc - optind;
 197   if (2 <= n_args)
 198     {
 199       error (0, 0, _("too many templates"));
 200       usage (EXIT_FAILURE);
 201     }
 202
 203   if (n_args == 0)
 204     {
 205       use_dest_dir = true;
 206       template = (char *) default_template;
 207     }
 208   else
 209     {
 210       template = argv[optind];
 211     }
 212
 213   x_count = count_trailing_X_s (template);
 214   if (x_count < 3)
 215     error (EXIT_FAILURE, 0, _("too few X's in template %s"), quote (template));
 216
 217   if (use_dest_dir)
 218     {
 219       if (deprecated_t_option)
 220         {
 221           char *env = getenv ("TMPDIR");
 222           dest_dir = (env && *env
 223                       ? env
 224                       : (dest_dir_arg ? dest_dir_arg : "/tmp"));
 225
 226           if (last_component (template) != template)
 227             error (EXIT_FAILURE, 0,
 228                    _("invalid template, %s, contains directory separator"),
 229                    quote (template));
 230         }
 231       else
 232         {
 233           if (dest_dir_arg && *dest_dir_arg)
 234             dest_dir = dest_dir_arg;
 235           else
 236             {
 237               char *env = getenv ("TMPDIR");
 238               dest_dir = (env && *env ? env : "/tmp");
 239             }
 240           if (IS_ABSOLUTE_FILE_NAME (template))
 241             error (EXIT_FAILURE, 0,
 242                    _("invalid template, %s; with --tmpdir,"
 243                      " it may not be absolute"),
 244                    quote (template));
 245         }
 246
 247       template = file_name_concat (dest_dir, template, NULL);
 248     }
 249   else
 250     {
 251       template = xstrdup (template);
 252     }
 253
 254   /* Make a copy to be used in case of diagnostic, since failing
 255      mkstemp may leave the buffer in an undefined state.  */
 256   dest_name = xstrdup (template);
 257
 258   if (create_directory)
 259     {
 260       int err = mkdtemp_len (dest_name, x_count, dry_run);
 261       if (err != 0)
 262         {
 263           error (0, errno, _("failed to create directory via template %s"),
 264                  quote (template));
 265           status = EXIT_FAILURE;
 266         }
 267     }
 268   else
 269     {
 270       int fd = mkstemp_len (dest_name, x_count, dry_run);
 271       if (fd < 0 || (!dry_run && close (fd) != 0))
 272         {
 273           error (0, errno, _("failed to create file via template %s"),
 274                  quote (template));
 275           status = EXIT_FAILURE;
 276         }
 277     }
 278
 279   if (status == EXIT_SUCCESS)
 280     puts (dest_name);
 281
 282 #ifdef lint
 283   free (dest_name);
 284   free (template);
 285 #endif
 286
 287   exit (status);
 288 }