src/cksum.c

   1 /* cksum -- calculate and print POSIX checksums and sizes of files
   2    Copyright (C) 1992, 1995-2006, 2008-2010 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 \f
  17 /* Written by Q. Frank Xia, qx@math.columbia.edu.
  18    Cosmetic changes and reorganization by David MacKenzie, djm@gnu.ai.mit.edu.
  19
  20   Usage: cksum [file...]
  21
  22   The code segment between "#ifdef CRCTAB" and "#else" is the code
  23   which calculates the "crctab". It is included for those who want
  24   verify the correctness of the "crctab". To recreate the "crctab",
  25   do something like the following:
  26
  27       cc -DCRCTAB -o crctab cksum.c
  28       crctab > crctab.h
  29
  30   This software is compatible with neither the System V nor the BSD
  31   `sum' program.  It is supposed to conform to POSIX, except perhaps
  32   for foreign language support.  Any inconsistency with the standard
  33   (other than foreign language support) is a bug.  */
  34
  35 #include <config.h>
  36
  37 /* The official name of this program (e.g., no `g' prefix).  */
  38 #define PROGRAM_NAME "cksum"
  39
  40 #define AUTHORS proper_name ("Q. Frank Xia")
  41
  42 #include <stdio.h>
  43 #include <sys/types.h>
  44 #include <stdint.h>
  45 #include "system.h"
  46 #include "xfreopen.h"
  47
  48 #ifdef CRCTAB
  49
  50 # define BIT(x) ((uint_fast32_t) 1 << (x))
  51 # define SBIT   BIT (31)
  52
  53 /* The generating polynomial is
  54
  55           32   26   23   22   16   12   11   10   8   7   5   4   2   1
  56     G(X)=X  + X  + X  + X  + X  + X  + X  + X  + X + X + X + X + X + X + 1
  57
  58   The i bit in GEN is set if X^i is a summand of G(X) except X^32.  */
  59
  60 # define GEN    (BIT (26) | BIT (23) | BIT (22) | BIT (16) | BIT (12) \
  61                  | BIT (11) | BIT (10) | BIT (8) | BIT (7) | BIT (5) \
  62                  | BIT (4) | BIT (2) | BIT (1) | BIT (0))
  63
  64 static uint_fast32_t r[8];
  65
  66 static void
  67 fill_r (void)
  68 {
  69   int i;
  70
  71   r[0] = GEN;
  72   for (i = 1; i < 8; i++)
  73     r[i] = (r[i - 1] << 1) ^ ((r[i - 1] & SBIT) ? GEN : 0);
  74 }
  75
  76 static uint_fast32_t
  77 crc_remainder (int m)
  78 {
  79   uint_fast32_t rem = 0;
  80   int i;
  81
  82   for (i = 0; i < 8; i++)
  83     if (BIT (i) & m)
  84       rem ^= r[i];
  85
  86   return rem & 0xFFFFFFFF;      /* Make it run on 64-bit machine.  */
  87 }
  88
  89 int
  90 main (void)
  91 {
  92   int i;
  93
  94   fill_r ();
  95   printf ("static uint_fast32_t const crctab[256] =\n{\n  0x00000000");
  96   for (i = 0; i < 51; i++)
  97     {
  98       printf (",\n  0x%08x, 0x%08x, 0x%08x, 0x%08x, 0x%08x",
  99               crc_remainder (i * 5 + 1), crc_remainder (i * 5 + 2),
 100               crc_remainder (i * 5 + 3), crc_remainder (i * 5 + 4),
 101               crc_remainder (i * 5 + 5));
 102     }
 103   printf ("\n};\n");
 104   exit (EXIT_SUCCESS);
 105 }
 106
 107 #else /* !CRCTAB */
 108
 109 # include <getopt.h>
 110 # include "long-options.h"
 111 # include "error.h"
 112
 113 /* Number of bytes to read at once.  */
 114 # define BUFLEN (1 << 16)
 115
 116 static uint_fast32_t const crctab[256] =
 117 {
 118   0x00000000,
 119   0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
 120   0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
 121   0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
 122   0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
 123   0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
 124   0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
 125   0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
 126   0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
 127   0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
 128   0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
 129   0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
 130   0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
 131   0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
 132   0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
 133   0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
 134   0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
 135   0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
 136   0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
 137   0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
 138   0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
 139   0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
 140   0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
 141   0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
 142   0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
 143   0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
 144   0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
 145   0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
 146   0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
 147   0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
 148   0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
 149   0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
 150   0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
 151   0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
 152   0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
 153   0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
 154   0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
 155   0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
 156   0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
 157   0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
 158   0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
 159   0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
 160   0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
 161   0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
 162   0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
 163   0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
 164   0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
 165   0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
 166   0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
 167   0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
 168   0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
 169   0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
 170 };
 171
 172 /* Nonzero if any of the files read were the standard input. */
 173 static bool have_read_stdin;
 174
 175 /* Calculate and print the checksum and length in bytes
 176    of file FILE, or of the standard input if FILE is "-".
 177    If PRINT_NAME is true, print FILE next to the checksum and size.
 178    Return true if successful.  */
 179
 180 static bool
 181 cksum (const char *file, bool print_name)
 182 {
 183   unsigned char buf[BUFLEN];
 184   uint_fast32_t crc = 0;
 185   uintmax_t length = 0;
 186   size_t bytes_read;
 187   FILE *fp;
 188   char length_buf[INT_BUFSIZE_BOUND (uintmax_t)];
 189   char const *hp;
 190
 191   if (STREQ (file, "-"))
 192     {
 193       fp = stdin;
 194       have_read_stdin = true;
 195       if (O_BINARY && ! isatty (STDIN_FILENO))
 196         xfreopen (NULL, "rb", stdin);
 197     }
 198   else
 199     {
 200       fp = fopen (file, (O_BINARY ? "rb" : "r"));
 201       if (fp == NULL)
 202         {
 203           error (0, errno, "%s", file);
 204           return false;
 205         }
 206     }
 207
 208   while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0)
 209     {
 210       unsigned char *cp = buf;
 211
 212       if (length + bytes_read < length)
 213         error (EXIT_FAILURE, 0, _("%s: file too long"), file);
 214       length += bytes_read;
 215       while (bytes_read--)
 216         crc = (crc << 8) ^ crctab[((crc >> 24) ^ *cp++) & 0xFF];
 217       if (feof (fp))
 218         break;
 219     }
 220
 221   if (ferror (fp))
 222     {
 223       error (0, errno, "%s", file);
 224       if (!STREQ (file, "-"))
 225         fclose (fp);
 226       return false;
 227     }
 228
 229   if (!STREQ (file, "-") && fclose (fp) == EOF)
 230     {
 231       error (0, errno, "%s", file);
 232       return false;
 233     }
 234
 235   hp = umaxtostr (length, length_buf);
 236
 237   for (; length; length >>= 8)
 238     crc = (crc << 8) ^ crctab[((crc >> 24) ^ length) & 0xFF];
 239
 240   crc = ~crc & 0xFFFFFFFF;
 241
 242   if (print_name)
 243     printf ("%u %s %s\n", (unsigned int) crc, hp, file);
 244   else
 245     printf ("%u %s\n", (unsigned int) crc, hp);
 246
 247   if (ferror (stdout))
 248     error (EXIT_FAILURE, errno, "-: %s", _("write error"));
 249
 250   return true;
 251 }
 252
 253 void
 254 usage (int status)
 255 {
 256   if (status != EXIT_SUCCESS)
 257     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 258              program_name);
 259   else
 260     {
 261       printf (_("\
 262 Usage: %s [FILE]...\n\
 263   or:  %s [OPTION]\n\
 264 "),
 265               program_name, program_name);
 266       fputs (_("\
 267 Print CRC checksum and byte counts of each FILE.\n\
 268 \n\
 269 "), stdout);
 270       fputs (HELP_OPTION_DESCRIPTION, stdout);
 271       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 272       emit_ancillary_info ();
 273     }
 274   exit (status);
 275 }
 276
 277 int
 278 main (int argc, char **argv)
 279 {
 280   int i;
 281   bool ok;
 282
 283   initialize_main (&argc, &argv);
 284   set_program_name (argv[0]);
 285   setlocale (LC_ALL, "");
 286   bindtextdomain (PACKAGE, LOCALEDIR);
 287   textdomain (PACKAGE);
 288
 289   atexit (close_stdout);
 290
 291   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE, Version,
 292                       usage, AUTHORS, (char const *) NULL);
 293   if (getopt_long (argc, argv, "", NULL, NULL) != -1)
 294     usage (EXIT_FAILURE);
 295
 296   have_read_stdin = false;
 297
 298   if (optind == argc)
 299     ok = cksum ("-", false);
 300   else
 301     {
 302       ok = true;
 303       for (i = optind; i < argc; i++)
 304         ok &= cksum (argv[i], true);
 305     }
 306
 307   if (have_read_stdin && fclose (stdin) == EOF)
 308     error (EXIT_FAILURE, errno, "-");
 309   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 310 }
 311
 312 #endif /* !CRCTAB */